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Archive of Mathematica weekly newsletters

Nasser M. Abbasi

July 4, 2021   Compiled on July 4, 2021 at 2:04pm

1 Year 2021
2 Year 2020
3 Year 2018
4 Year 2017
5 Year 2016
6 Year 2015
7 Year 2014
8 Year 2013

Chapter 1
Year 2021

 1.1 Thursday, May 27, 2021
 1.2 Thursday, May 20, 2021
 1.3 Thursday, May 13, 2021
 1.4 Thursday, April 29, 2021
 1.5 Thursday, April 22, 2021
 1.6 Thursday, April 15, 2021
 1.7 Thursday, April 1, 2021
 1.8 Thursday, March 25, 2021
 1.9 Thursday, March 18, 2021
 1.10 Thursday, March 11, 2021
 1.11 Thursday, February 25, 2021
 1.12 Thursday, February 18, 2021
 1.13 Thursday, February 11, 2021
 1.14 Thursday, February 4, 2021
 1.15 Thursday, January 28, 2021
 1.16 Thursday, January 21, 2021
 1.17 Thursday, January 14, 2021
 1.18 Thursday, January 7, 2021

1.1 Thursday, May 27, 2021

  1.1.1 Top new questions this week
  1.1.2 Greatest hits from previous weeks
  1.1.3 Can you answer these questions?

1.1.1 Top new questions this week

   Is Internal‘StringToDouble broken in 12.3?
   in V 12.3, expression in notebook shakes when scrolling mouse to edit them. How to stop this effect?
   Programming language prototyping in Mathematica
   WriteString to TCP socket appears to be broken in Mathematica 12.3
   DirichletCondition doesn’t always work with RegionBoundary
   What are the key reasons for the performance improvements in 12.3?
   Default window size too small in version 12.3 (in Windows 10)

Is Internal‘StringToDouble broken in 12.3?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246449

I believe Internal`StringToDouble was the only way to fast convert string into numbers. Now in V12.3 it was removed: Internal`StringToDouble["1"]

asked by Murta https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2266 17 votes

answered by Itai Seggev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4848 20 votes

in V 12.3, expression in notebook shakes when scrolling mouse to edit them. How to stop this effect?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246400

I noticed in V 12.3, when trying to edit an expression in a cell, and moving/scrolling the mouse, the expression itself shakes. It seems to auto-resize or adjust while one is editing it. This does not ...

asked by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 14 votes

answered by MassDefect https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42264 16 votes

Programming language prototyping in Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246507

Are you aware of any projects using the Wolfram language resp. Mathematica as an environment to explore the design of programming languages - in particular languages with a focus on mathematics (...

asked by Math Gaudium https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74255 12 votes

answered by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 18 votes

WriteString to TCP socket appears to be broken in Mathematica 12.3

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246444

I have a large codebase in which some functions make calls to Python TCP servers. The code used to work perfectly in Mathematica 12.2, but has not worked since I ...

asked by Shredderroy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9257 11 votes

answered by Dorian B. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23275 2 votes

DirichletCondition doesn’t always work with RegionBoundary

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246520

I am trying to solve the heat equation on a circle with a square shaped hole in it. It works:

asked by Pillsy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=531 9 votes

answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 11 votes

What are the key reasons for the performance improvements in 12.3?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246476

The built in benchmark test on my stationary workstation shows an improvement from 2.82 to 5.99, all other hardware and operating systems settings the same. This looks very good. My question is: What ...

asked by FredrikD https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1635 9 votes

answered by Dan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42162 5 votes

Default window size too small in version 12.3 (in Windows 10)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246466

After starting Mathematica 12.3, the default window size is like this, it’s too small for me, I don’t want to manually drag the window every time. I have tried this,

asked by matrix89 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5379 7 votes

1.1.2 Greatest hits from previous weeks

   Multivariable Taylor expansion does not work as expected
   How to calculate contour integrals with Mathematica?
   What does ”Tag Integer is Protected” message mean?
   Is there an open source implementation of Mathematica-the-language?
   How to express trigonometric equation in terms of of given trigonometric function?
   How can I plot a graph of an integral?
   Find eigen energies of time-independent Schrödinger equation

Multivariable Taylor expansion does not work as expected

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=15023

The basic multivariable Taylor expansion formula around a point is as follows:

\[ f(\mathbf r + \mathbf a) = f(\mathbf r) + (\mathbf a \cdot \nabla )f(\mathbf r) + \frac {1}{2!}(\mathbf a \cdot \nabla ) \]

asked by matheorem https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4742 65 votes

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 73 votes

How to calculate contour integrals with Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=34073

How to calculate the integral of \(\frac {1}{\sqrt {4 z^2 + 4 z + 3}}\) over the unit circle counterclockwise for each branch of the integrand?

asked by user64494 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7152 42 votes

answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 64 votes

What does ”Tag Integer is Protected” message mean?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=6738

(Newbie question)

For every function I define I get this message: When I close and reopen Mathematica, and re-enter the function definition, I don’t get the message anymore. What does it mean?

asked by stevenvh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1450 11 votes

answered by J. M.’s ennui https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 13 votes

Is there an open source implementation of Mathematica-the-language?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=4454

I’ve seen questions before such as ”What is the best open-source equivalent for Mathematica?”, but that specific question (and that line of inquiry in general) cares more about the computer algebra ...

asked by sblom https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=178 124 votes

answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 86 votes

How to express trigonometric equation in terms of of given trigonometric function?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=434

How can I express a trigonometric equation / identity in terms of a given trigonometric function?

using following trigonometric identities

asked by Prashant Bhate https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=99 30 votes

answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 37 votes

How can I plot a graph of an integral?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=78451

I want to plot the following function:

\[ \int \left (\frac {\Gamma (x+1)}{2}-\frac {\Gamma (x-1)}{2}\right ) \, dx \]

asked by Anixx https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=651 4 votes

answered by k_v https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=24727 9 votes

Find eigen energies of time-independent Schrödinger equation

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=32293

I’m trying to get the eigenvalues of a one dimensional time-independent Schrödinger equation,

\(-\frac {h^2}{2m_0}\frac {d^2\psi }{dx^2}+U(x)~\psi =Ei~\psi \)

where \(U(x)\) is some potential and Ei is the ...

asked by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 49 votes

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 46 votes

1.1.3 Can you answer these questions?

   What is ”Flatten” doing to my elements?
   Inconsistent boundary and initial conditions when solving sine Gordon equation
   Step-by-step solution for a Limit

What is ”Flatten” doing to my elements?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246395

Here’s some of my code. x1 results in returning the position of a list in a {{{n1}},{{n2}}...}. Im trying to flatten it such that the list reads out as {n1,n2,n3....} some how it’s adding elements.

asked by MT Cup https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79502 1 vote

Inconsistent boundary and initial conditions when solving sine Gordon equation

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246596

I have been trying to solve the following sine Gordon equation \(\partial _{x,x} u(x,t) - \partial _{t,t} u(x,t) - \sin (u(x,t)) - \alpha \partial _t u(x,t) + \gamma = 0\), for \(x \in [0,15]\) and

asked by Đạt Lê Thành https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68852 1 vote

Step-by-step solution for a Limit

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246560

Is it possible in Mathematica to get a step-by-step evaluation of some functions? Such that Mathematica is outputting not only the result but all the stages that have led to it? If so, how does one do ...

asked by putti.123 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=80178 1 vote

1.2 Thursday, May 20, 2021

  1.2.1 Top new questions this week
  1.2.2 Greatest hits from previous weeks
  1.2.3 Can you answer these questions?

1.2.1 Top new questions this week

   Stable fluids code for electromagnetic mixture application
   How can I create an animation showing how a circular sector deformed to a cone?
   Dataset from association of lists doesn’t work
   Creating the Yin Yang symbol with minimal code
   On the ordering of the vertices of a polygon
   Is it possible to vary the thickness of curves according to their color code
   How can I style a Line like ”Glassrectangle”?

Stable fluids code for electromagnetic mixture application

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246091

This code has been translated from the original Jos Stam code and improved with some Mathematica functions. It solves problem of viscous incompressible flow with electromagnetic force in a rectangle ...

asked by Alex Trounev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58388 14 votes

answered by xzczd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1871 11 votes

How can I create an animation showing how a circular sector deformed to a cone?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246171

I want to create the following animation with Mathematica.

What is the simplest way to do so? My first effort:

asked by Kim Jong Un https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42141 12 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes

Dataset from association of lists doesn’t work

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246088

Mathematica 12 on wolfram cloud isn’t rendering the table for an association of lists. According to the documentation you should be able to make columns in the table by:

However I tried this

asked by Ion Sme https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=62529 10 votes

answered by WReach https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=142 9 votes

Creating the Yin Yang symbol with minimal code

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246309

The following code creates the Yin Yang symbol

asked by nilo de roock https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=156 9 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 15 votes

On the ordering of the vertices of a polygon

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245994

Writing:

pts = {{1, 0}, {2, 0}, {2, 3}, {3, 3}, {3, 4}, {0, 4}, {0, 3}, {1, 3}, {1, 0}}; 
Graphics[{Red, Point[pts], Blue, Line[pts]}]

we get:

and all of this ...

asked by Rolex https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=80016 9 votes

answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 15 votes

Is it possible to vary the thickness of curves according to their color code

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246125 I have this data data = Table[{x, Sin[5 x], Tanh[3 x]}, {x, -1, 1, 0.01}];

which I plot as follows

asked by valar morghulis https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26937 8 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 6 votes

How can I style a Line like ”Glassrectangle”?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246046

I’d like a thick Line to look like ChartElementFunction -> "GlassRectangle" How can that be accomplished?

asked by Gannicus https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=80033 8 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 11 votes

1.2.2 Greatest hits from previous weeks

   What’s the most difficult multidimensional integral that Mathematica has solved?
   Extract real part of a complex expression better than Re does
   Exporting graphics to PDF - huge file
   My Girlfriend is going to prison...Save her with Math
   How to plot an ellipse?
   Is there something like DensityPlot3D to visualize atomic orbitals?
   Calling Correct Function for Plotting DiracDelta

What’s the most difficult multidimensional integral that Mathematica has solved?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222184

I am interested in benchmarking numerical integration methods and am trying to develop a wider set of difficult multivariate examples. For my particular methods, I only want to look at non-negative-...

asked by ben18785 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19278 6 votes

Extract real part of a complex expression better than Re does

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3306

I have a complex expression with real positive variables only.

Mathematica Input Style:

asked by max https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=796 34 votes

answered by nixeagle https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=814 54 votes

Exporting graphics to PDF - huge file

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=1542

I want to draw some basic surfaces, export them to PDF and include them in a LaTeX file. I create a simple 3D graphics object, for instance with

asked by Matthew Leingang https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=395 109 votes

My Girlfriend is going to prison...Save her with Math

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=135937

Salacious title, but true story.

asked by Prisoners Dilema https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46025 42 votes

answered by bobthechemist https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7167 23 votes

How to plot an ellipse?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=20100

I’m new to Mathematica, and I’m finding it difficult to plot an ellipse. I tried using

 Plot[(x/5)^2 + (y/3)^2 == 1, {x, -5, 5}, {y, -3, 3}]

but I’m getting ...

asked by Sriram https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6075 18 votes

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 30 votes

Is there something like DensityPlot3D to visualize atomic orbitals?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=32378

I’m visualizing some hydrogen like atomic orbitals. For looking at plane slices of the probability density, the DensityPlot function works well, and with something ...

asked by Peeter Joot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10 45 votes

answered by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 25 votes

Calling Correct Function for Plotting DiracDelta

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3506

I am wondering what is the correct function in Mathematica to plot the true impulse function, better known as the DiracDelta[] function. When using this inside of a ...

asked by night owl https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=116 17 votes

answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 19 votes

1.2.3 Can you answer these questions?

   Speeding up this function?
   Error when integrating with constants?
   Is there an analog of ArrayQ for datasets?

Speeding up this function?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246242 Is there a way to speed this function?

asked by An old man in the sea. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=11313 2 votes

Error when integrating with constants?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246300

I’m trying to integrate an ellipse: (x^2)/alpha^2) + ((y^2)/beta^2) = 1. I am not sure if I should have insert constants for alpha and beta or if there’s a way to keep them there.

This is my code

asked by user80088 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=80088 1 vote

answered by Daniel Huber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46318 0 votes

Is there an analog of ArrayQ for datasets?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246152

ArrayQ provides a nice way to check for missing data (specifically, it checks if the array is ragged). But if you import your data as a dataset, and apply ArrayQ, it will return False for both ragged ...

asked by theorist https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45215 1 vote

1.3 Thursday, May 13, 2021

  1.3.1 Top new questions this week
  1.3.2 Greatest hits from previous weeks
  1.3.3 Can you answer these questions?

1.3.1 Top new questions this week

   Finding ”chains” of numbers in a matrix
   How to formulate this problem in Mathematica?
   Problem with optimal control and Pontryagin’s maximum principle
   Sorting Associations by DayName (day of week) using KeySort and/or KeySortBy
   Using the PowerPoint’s laser pointer in symbols of plots
   How would one add Hyperreals as a new type to Mathematica?
   Extract held value from Association

Finding ”chains” of numbers in a matrix

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245937

To give some context, this problem is related to music theory. I have a matrix I’m generating with this code:

asked by Eriek https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18649 6 votes

answered by thorimur https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=63584 9 votes

How to formulate this problem in Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245908

Say, I have the following expressions

f = R[p] 
g = S[p]

where R,S are rational functions, and I want to find a polynomial such that

asked by nilo de roock https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=156 6 votes

answered by Roman https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26598 11 votes

Problem with optimal control and Pontryagin’s maximum principle

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245797

For dynamic system: \(\dot {x}=\frac {df}{dx}+u\) where \(f=e^{-x^2}\) It is necessary to develop optimal control, minimizing criterion: \(J= \int _{0}^{t_f} ((\frac {df}{dx})^2+u^2) \,dt \) Algorithm:

We ...

asked by dtn https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=67019 6 votes

answered by Alex Trounev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58388 7 votes

Sorting Associations by DayName (day of week) using KeySort and/or KeySortBy

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245721

I have an association where the keys are the days of the week:

asked by theorist https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45215 6 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 6 votes

Using the PowerPoint’s laser pointer in symbols of plots

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245800

I am interested in exploiting a symbol that is similar to the PowerPoint’s laser pointer in the role of PlotMarkers. Is there any idea to create that!? This symbol ...

asked by Inzo Babaria https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=33967 5 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 12 votes

How would one add Hyperreals as a new type to Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245782

Hyperreals are an extension to the real numbers; they formalise the concepts of infinities and infinitestimals as numbers, rather than the named limit points outside of the system of reals and form ...

asked by Julian Moore https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12858 5 votes

Extract held value from Association

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245784

Consider an association which contains a key which must not be prematurely evaluated. assoc = <| key :> value |>

For example, a value of ...

asked by Anti Earth https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=32591 5 votes

answered by Leonid Shifrin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=81 6 votes

1.3.2 Greatest hits from previous weeks

   1 Plot, 2 Scale/Axis
   How to perform a multi-peak fitting?
   Standard deck of 52 playing cards in curated data?
   Is it possible to export the equations from Mathematica to MATLAB?
   LaTeXand Mathematica
   How can I plot implicit equations?
   Calling Correct Function for Plotting DiracDelta

1 Plot, 2 Scale/Axis

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=627

I would like to plot those two datasets on top of each other. But they have very different range on the \(y\) axis. How can I have two different axis?

I found the following on the help menu but quite ...

asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 152 votes

answered by ArgentoSapiens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=92 152 votes

How to perform a multi-peak fitting?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=26336

I am wondering how to implement the multi-peak detecting and fitting in Mathematica. Following is an example of fitting the data using three peaks (such that the data ~ peak1 + peak2 + peak3). The ...

asked by Everett You https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1389 55 votes

answered by Silvia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=17 55 votes

Standard deck of 52 playing cards in curated data?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16108

I am not sure how to find out what all is included as curated data. For example, are the individual images of each of the 52 cards in a standard deck of playing cards included?

If not, is there a way ...

asked by JohnD https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1629 25 votes

answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 23 votes

Is it possible to export the equations from Mathematica to MATLAB?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=14035

Is it possible to export the output expressions from Mathematica computations (e.g., equations) in valid MATLAB syntax?

asked by Seyhmus Güngören https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4256 43 votes

answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 48 votes

LaTeXand Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=736

I quite often would like to draw graphics in my LaTeXdocuments using Mathematica. I have encountered three problems. I would like to know if there are any workarounds to these problems

I would ...

asked by Thomas Rot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=227 130 votes

answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 46 votes

How can I plot implicit equations?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=34668

If you enter the following into Wolfram — Alpha, you get nice graphs:

graph 4 x^4 + y^2 = 2

How do you do this in Mathmatica? I realize that these are not ...

asked by Rollie https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10174 40 votes

answered by Timothy Wofford https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9391 41 votes

Calling Correct Function for Plotting DiracDelta

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3506

I am wondering what is the correct function in Mathematica to plot the true impulse function, better known as the DiracDelta[] function. When using this inside of a ...

asked by night owl https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=116 17 votes

answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 19 votes

1.3.3 Can you answer these questions?

   Excess lines in the solution plot of vector ODE
   Algorithmically imposing a substitution in a difficult integral
   How to expand a rational function as a single fraction

Excess lines in the solution plot of vector ODE

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245826

I’ve got an ODE system, which I attempt to solve by two ways: solving the system itself, and using vector ODE. Here is code of first way:

asked by Cpp Nosavvier https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79893 3 votes

Algorithmically imposing a substitution in a difficult integral

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245884

Consider the following integral: \[ I = \frac {1}{\pi c^2} \int \limits _{r=0}^c 2 \pi r\ e^{-\frac { \left (\sqrt {a^2 - r^2} -\sqrt {b^2 - r^2} \right )}{\lambda }}\ dr \] under the conditions \(a>b>c>\)...

asked by David G. Stork https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9735 2 votes

How to expand a rational function as a single fraction

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245673

This has been annoying me for a long time. I want a rational function to be represented in the form

    n        0
anx--+-....a0x--
bmxm  + ....b0x0

But this seems to be quite difficult. Mathematica ...

asked by grdgfgr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=28163 2 votes

answered by Ulrich Neumann https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53677 0 votes

1.4 Thursday, April 29, 2021

  1.4.1 Top new questions this week
  1.4.2 Greatest hits from previous weeks
  1.4.3 Can you answer these questions?

1.4.1 Top new questions this week

   Replacing duplicates instead of deleting them
   RecurrenceTable and While
   Speed up averaging of numerically solved differential equations
   FEM: how to redo a composed boundary mesh for better quality?
   Were these Images made with Wolfram Language / Mathematica?
   How to find the repeated elements in a vector
   How to separate two regions in DensityPlot

Replacing duplicates instead of deleting them

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245078

My code replaces each repeated element by ”X”.

asked by azerbajdzan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53172 10 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 18 votes

RecurrenceTable and While

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2450308

Good day. Let’s take an example from Help on RecurrenceTable

asked by macros https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79485 6 votes

answered by Roman https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26598 3 votes

Speed up averaging of numerically solved differential equations

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245121

I deals with a coupled system with non-linear differential equations of first order. I perform numerical solution with NDSolve and then use obtained solutions,

asked by Artem Alexandrov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=49992 5 votes

answered by Alex Trounev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58388 1 vote

FEM: how to redo a composed boundary mesh for better quality?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245050

Suppose you have region with 2 materials: one embedding material matrix containing some particles

asked by Mauricio Fernández https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=24710 4 votes

answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 5 votes

Were these Images made with Wolfram Language / Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245080

I am currently writing a paper in which Fibonacci Spirals are discussed. In the text of the paper the mathematics of these objects is discussed and the relevant equations and relationships are shown ...

asked by urquiza https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79636 4 votes

answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 9 votes

How to find the repeated elements in a vector

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245068

Is there a way to write a function where the input is a vector and the output is the elements in the vector that are repeated? I was trying to use something along the lines:

asked by Trashlife https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79628 4 votes

answered by Roman https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26598 7 votes

How to separate two regions in DensityPlot

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245051

I want to separate two regions in DensityPlot similar to the attached image.

In my code and the obtained result, I want to separate the region with less value of one from others. How can I do this? ...

asked by mehrosadat ebrahimi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=40575 4 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 4 votes

1.4.2 Greatest hits from previous weeks

   How to graph a sphere with cartesian equations?
   Parallel and perpendicular symbol from Mathematica to LaTeX
   How do I make a 3DPlot using cylindrical coordinates?
   What does Compile[] do to make code run so much faster?
   How do I clear all user defined symbols?
   Formatting legend text font
   How can I plot the direction field for a differential equation?

How to graph a sphere with cartesian equations?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=24169

I’m new to Mathematica and I need to ask how to graph a sphere, cylinder, etc.. using cartesian equations.

For example in sphere’s case \(x^2+y^2+z^2=1\)

I tried to use ...

asked by German https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7145 8 votes

answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 14 votes

Parallel and perpendicular symbol from Mathematica to LaTeX

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=46538

I want to get the following expression from Mathematica to LaTeX:

\[ \begin {bmatrix} E_{\parallel } \\ E_{\perp } \end {bmatrix} \]

I have tried to use inbuilt ’symbol’ character from the special ...

asked by Steve Hatcher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13314 20 votes

answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 27 votes

How do I make a 3DPlot using cylindrical coordinates?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19076

I’m trying to plot a function of the form \(z(r,\theta )\) where \(r \in [0, R]\) for a finite R, \(\theta \in [0,2\pi [\), and z is the third coordinate, a function of the first two. I couldn’t find anything ...

asked by Learning is a mess https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5643 19 votes

answered by whuber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=91 26 votes

What does Compile[] do to make code run so much faster?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2371758

I am looking for an ELI5 explanation of whatCompile[] in the Wolfram Language context does and why it works so much faster than uncompiled code in certain cases. I am trying to get more insight to ...

asked by anon248 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66458 20 votes

answered by chasly - supports Monica https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34024 9 votes

How do I clear all user defined symbols?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=850

Is there some way to do this other than going to Evaluation -> Quit kernel and firing a new one up?

asked by niklasfi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=82 99 votes

answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 98 votes

Formatting legend text font

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3433

I am using this code to plot a graph, and I am trying to make the font of the legend bigger.

asked by Julia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=525 20 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 25 votes

How can I plot the direction field for a differential equation?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8841

I’d like to plot the graph of the direction field for a differential equation, to get a feel for it. I’m a novice, right now, when it comes to plotting in Mathematica, so I’m hoping that someone can ...

asked by Matt Groff https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1735 33 votes

answered by Peter Breitfeld https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=307 26 votes

1.4.3 Can you answer these questions?

   Artifacts When Plotting Results of Numerical Integration
   How to solve a system with infinitely many equations?
   Custom multiplication operation between variables

Artifacts When Plotting Results of Numerical Integration

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2451018

I am trying to reproduce the following graph of phase shifts as function of frequency.

Please see my code bellow. I used Mathematica to solve for t1 and ...

asked by guestuser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76488 2 votes

How to solve a system with infinitely many equations?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245194

I need to solve the following system of (infinitely many) equations. I am looking for \(V(0,0)\)

\(t \in \{0,1,2.....\}\) with one caveat that \(s \leq 1+t\) should hold.

\( s \in \{1,2,3,L-1\}\)

fixed ...

asked by Monire Jalili https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=62240 1 vote

Custom multiplication operation between variables

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2452988

I am constructing polynomial expressions in the variables \(s[0],s[1],...,s[n]\) and I’m trying to define a new operation to simplify the expression:

asked by David https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72836 1 vote

1.5 Thursday, April 22, 2021

  1.5.1 Top new questions this week
  1.5.2 Greatest hits from previous weeks
  1.5.3 Can you answer these questions?

1.5.1 Top new questions this week

   joining three lists to plot data with errors
   Interpreting traditional math
   Is it possible to define conjugate of a function?
   Maximal circle packing inside a given square
   Some doubts about symbolic equations in Wolfram Mathematica
   Count number of balls in each bin, given a two-element sequence of balls and bins
   FEM: elastic cylinder under circumferential pressure

joining three lists to plot data with errors

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244887

I have three lists:

x = {x1, x2, ...}, 
y = {y1, y2, ...}, 
yErr = {y1Err, y2Err, ...}

that I want to join into the following format:

asked by uuu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42359 7 votes

answered by Ulrich Neumann https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53677 9 votes

Interpreting traditional math

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244672

There are two ways (afaik) to parse traditional math string to an expression:

asked by Kuba https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5478 7 votes

answered by Kuba https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5478 3 votes

Is it possible to define conjugate of a function?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244907

Could you help me, please? I have two complex functions of real variable f[x] and fc[x] such that one is a conjugate of another one. I’d like to take a conjugate of an expression that includes both of ...

asked by Svetlana https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72941 6 votes

answered by Daniel Huber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46318 9 votes

Maximal circle packing inside a given square

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244820

How to pack n equal disks(radius a/2) with maximal area inside a given rectangle ? I’m trying to solve this problem using Mathematicas Region functions. Here my approach: Maximize the area of the ...

asked by Ulrich Neumann https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53677 6 votes

answered by cvgmt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72111 6 votes

Some doubts about symbolic equations in Wolfram Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244961

I need to perform the following operations using Wolfram Mathematica. I have these equations:

ab = c + d+ e

d-= gh + i
f

    a
k = --
    c

I need to obtain \(k\) as a function of: \(a,b,c,e,\dots \)

asked by Skyhawk https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79597 5 votes

answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 9 votes

Count number of balls in each bin, given a two-element sequence of balls and bins

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244834

If I have a list:

{ball,ball,BINDIVIDER,ball,ball,ball,BINDIVIDER,BINDIVIDER,ball,BINDIVIDER,ball}

The balls and bins can be in any permutation. Then, the ...

asked by apkg https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=35029 5 votes

answered by WReach https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=142 6 votes

FEM: elastic cylinder under circumferential pressure

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244993

Suppose you have an elastic cylinder of radius \(R\) and height \(H\) and you want to solve the mechanical 3D equilibrium with Mathematica’s FEM. How do you impose a pressure \(p\) only on the cylinder ...

asked by Mauricio Fernández https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=24710 4 votes

answered by user21 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18437 4 votes

1.5.2 Greatest hits from previous weeks

   Plot data from txt file?
   How to make a Spherical Cow?
   What are the most common pitfalls awaiting new users?
   My Girlfriend is going to prison...Save her with Math
   Plotting the Star of Bethlehem
   Generate a Unit Circle Trigonometry
   Extract real part of a complex expression better than Re does

Plot data from txt file?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=5910

I have data in file.txt which can be expressed by 20000x11 matrix. I do not want to import all of these data. How can I plot graph of the column 1 & column 4?

asked by Gokce https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1297 21 votes

answered by user1066 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=106 24 votes

How to make a Spherical Cow?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=125043

Being a theoretical physicist, I always have a great respect for Spherical Cow. So I thought about making one myself. I am not sure how can I create (something considered to be the simplest!) this ...

asked by Sumit https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8070 69 votes

answered by andre314 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5467 76 votes

What are the most common pitfalls awaiting new users?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18393

As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...

asked by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 485 votes

answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 288 votes

My Girlfriend is going to prison...Save her with Math

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=135937

Salacious title, but true story.

asked by Prisoners Dilema https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46025 42 votes

answered by bobthechemist https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7167 23 votes

Plotting the Star of Bethlehem

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236499

Christmas is around the corner! In preparation, consider the polynomial f[x_,y_]:= 1/10 (4 - x^2 - 2 y^2)^2 + 1/2 (x^2 + y^2) 

and define \(r=(f_x,f_y)\) using the ...

asked by fwgb https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44151 30 votes

answered by Roman https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26598 22 votes

Generate a Unit Circle Trigonometry

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2456

Struggling often with Trigonometry I would like to have some code to generate this Unit Circle Trigonometry. Would be of great help when I need to transform some data :

asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 18 votes

answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 32 votes

Extract real part of a complex expression better than Re does

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3306

I have a complex expression with real positive variables only.

Mathematica Input Style:

asked by max https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=796 34 votes

answered by nixeagle https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=814 53 votes

1.5.3 Can you answer these questions?

   Understanding the behavior of HypergeometricPFQ
   recursively find StringCases
   How to specify custom Loss function for Predict

Understanding the behavior of HypergeometricPFQ

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244963

this is my very post here, so I apologize for any possible format issue. I am using HypergeometricPFQ functions (more exactly \(_3F_2\)) as approximants for other more complicated functions. Here are ...

asked by avg https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79519 1 vote

recursively find StringCases

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244663

Can I recursively extract StringCases[] that match a specific pattern? Here is a minimalist example (not my actual problem):

asked by Conor Cosnett https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36681 2 votes

How to specify custom Loss function for Predict

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244702

How can I use Predict[Xs->Ys, Method->"NeuralNetwork"] to predict 90%-quantile (instead of mean value)? Utility Function does not work well for this case, because

it assumes ...

asked by Artem Vorozhtsov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61755 2 votes

1.6 Thursday, April 15, 2021

  1.6.1 Top new questions this week
  1.6.2 Greatest hits from previous weeks
  1.6.3 Can you answer these questions?

1.6.1 Top new questions this week

   Is there a neat code to swap elements of a list?
   Stokes equations in 2D with traction boundary conditions
   Transform a number to a factorial
   Stopping condition for FindMinimum / FindMaximum
   Efficiently compute Minkowski sum of a 2D Region and a Disc of radius r?
   Random orthogonal matrix
   Detecting patterns in a graph network

Is there a neat code to swap elements of a list?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244314

I want to swap the list to make a new list as follows. The code works but I’m wondering if there is a neat code, or an elegant way to do this.

asked by anhnha https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18805 9 votes

answered by kirma https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=3056 10 votes

Stokes equations in 2D with traction boundary conditions

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244482

This is a follow-up to a previous question (see here). We would like to solve the two-dimensional Stokes equations using the FEM package in Mathematica, when we prescribe traction boundary conditions. ...

asked by Alex R https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=78043 7 votes

answered by Oleksii Semenov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=63028 3 votes

Transform a number to a factorial

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244566

I came across the need to transform a number into a factorial n, with positive integer n. I have searched in the MMA information but I can’t find anything like that. I imagine an input, which verifies ...

asked by zeros https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26849 7 votes

answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 6 votes

Stopping condition for FindMinimum / FindMaximum

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244313

This seems like it should be a simple question – but I am looking to use a ”home made” stopping condition with FindMaximum, while evaluating a very complex function. Printing out the ...

asked by Richard E https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79342 7 votes

answered by Daniel Huber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46318 8 votes

Efficiently compute Minkowski sum of a 2D Region and a Disc of radius r?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244565

Given a 2D Mathematica Region, e.g. A = Region[RegionDifference[Disk[{0, 0}, 2], Disk[{2, 0}, 1]]], how can I grow the region by an arbitrary radius r? For example, ...

asked by Aaron T. Becker https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76690 6 votes

answered by cvgmt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72111 5 votes

Random orthogonal matrix

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244316

Is there a way to generate real random orthogonal matrices in mathematica? If Q is an orthogonal matrix, it’s properties are

asked by Jasmine https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73364 6 votes

answered by Henrik Schumacher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=38178 9 votes

Detecting patterns in a graph network

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244592

If we create a random graph

Chop[LowerTriangularize[RandomReal[{-1, 1}, {10, 10}], -1], 0.6] /.0 -> \[Infinity] // MatrixForm 
WeightedAdjacencyGraph[%]

How can ...

asked by Teabelly https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=56986 5 votes

answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 6 votes

1.6.2 Greatest hits from previous weeks

   What do the X and Y axis stand for in the Fourier transform domain?
   Plot, extract data to a file
   Get a ”step-by-step” evaluation in Mathematica
   How to add a vertical line to a plot
   Selecting every n-th element from a list
   How to graph a sphere with cartesian equations?
   Conversion of Sine to Cosine

What do the X and Y axis stand for in the Fourier transform domain?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=85139

In Wolfram Mathematica the function Fourier has the following declaration

Fourier[list]

And after a list is given to the ...

asked by user253956 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29958 27 votes

answered by Hugh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12558 61 votes

Plot, extract data to a file

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19859

I need to save data that Mathematica uses inside the Plot command. The format that I would like to have is:

x1 y1 
x2 y2

asked by molkee https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5097 30 votes

answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 47 votes

Get a ”step-by-step” evaluation in Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=148

Is it possible in Mathematica to get a step-by-step evaluation of some functions; that’s to say, outputting not only the result but all the stages that have led to it? If so, how does one do it?

asked by Cydonia7 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44 131 votes

answered by J. M.’s ennui https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 109 votes

How to add a vertical line to a plot

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3561

In the plot below I would like to add two vertical lines at \(x = \frac {\pi }{15} \pm \frac {1}{20}\). How can I do that?

asked by sjdh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=515 64 votes

answered by Ajasja https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=745 83 votes

Selecting every n-th element from a list

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=64003 I have a list:

data = {4, 5, 7, 8, 9, 5, 3, 2, 1, 2, 13, 12};

I want to take those elements in the list which are located at equal distances, say, every third ...

asked by Suro https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=20003 37 votes

answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 34 votes

How to graph a sphere with cartesian equations?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=24169

I’m new to Mathematica and I need to ask how to graph a sphere, cylinder, etc.. using cartesian equations.

For example in sphere’s case \(x^2+y^2+z^2=1\)

I tried to use ...

asked by German https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7145 7 votes

answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 13 votes

Conversion of Sine to Cosine

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=67521

I’m solving equations with many Cosines and Sines. And I want to convert all the Sines to Cosines using trigonometric formulas such as cos(x)=sin(x+pi/2). How can I do this?

asked by YongCheol Kwon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23041 4 votes

answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 2 votes

1.6.3 Can you answer these questions?

   RandomInstance of GeometricScene producing unexpected result
   Solving an ordinary differential equation with boundary condition at infinity
   How to use ScalingFunctions with Graphics ChartElements

RandomInstance of GeometricScene producing unexpected result

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244335

Consider the following scene as an example:

asked by user13892 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13892 1 vote

Solving an ordinary differential equation with boundary condition at infinity

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244342

I want to solve the following differential equation  f''[z] + (1/z)*f'[z] - f[z] + f[z]^3 == 0

subject to the boundary conditions

asked by HeitorGalacian https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73726 1 vote

answered by Mariusz Iwaniuk https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26828 0 votes

How to use ScalingFunctions with Graphics ChartElements

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244387

How to draw spheres with BubbleChart with a reversed vertical axis? The 3rd example shows the problem (empty plot), likely caused by the transformation, but how to correct it?

asked by HuibH https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70256 3 votes

1.7 Thursday, April 1, 2021

  1.7.1 Top new questions this week
  1.7.2 Greatest hits from previous weeks
  1.7.3 Can you answer these questions?

1.7.1 Top new questions this week

   Are Mathematica’s maps copyright-free?
   Find all English words that can be comprised of Element Abbreviations found in the Periodic Table
   Efficient uniform sampling of certain Boolean matrices
   Incorrect integration from article?
   Running Mathematica in ’SpouseMode’
   Putting together several ListPlot 2D in a 3D graphic
   Combine SortBy with ReverseSortBy

Are Mathematica’s maps copyright-free?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=243660

Are the maps available in Mathematica copyright-free? For instance, if I generate the image

asked by sam wolfe https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=64001 13 votes

answered by Carl Lange https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57593 24 votes

Find all English words that can be comprised of Element Abbreviations found in the Periodic Table

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=243664

This question is majorely influenced by a meme...

Now, I thought... it would be interesting to see what kind of ”passwords” could one derive using Periodic Table :D Hence, I began to work ...

asked by e.doroskevic https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18696 9 votes

answered by creidhne https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=41569 3 votes

Efficient uniform sampling of certain Boolean matrices

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=243547

I want to uniformly sample \((0,1)\)-matrices with certain constraints. In particular, I want sum of each row to be rowsum and the sums of columns to equal ...

asked by kirma https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=3056 8 votes

answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 7 votes

Incorrect integration from article?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=243711

Recently I came across an interesting article by Daniel Lichtblau, where the integral

Integrate[Abs[x - y]^n, {x, 0, 1}, {y, 0, 1}]

asked by user64494 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7152 7 votes

answered by Ulrich Neumann https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53677 8 votes

Running Mathematica in ’SpouseMode’

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=243859

In this previous question I looked into a deprecated capability of Mathematica from Version 2. Mathematica command that allows it to read my intentions Thanks to all for your answers. I note that ...

asked by MikeY https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=47314 6 votes

answered by MikeY https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=47314 1 vote

Putting together several ListPlot 2D in a 3D graphic

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=243823

I’m trying to put together several different 2D plots in a 3D graphics to create a figure which would be like the one below (taken from https://aip.scitation.org/doi/10.1063/1.4998724 However my ...

asked by AntoineM https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79171 6 votes

answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 4 votes

Combine SortBy with ReverseSortBy

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=243776

Suppose I have a dataset, which I want to sort according to two criteria. However, I want the first criteria to be sorted ascending, and the second descending. This would require to somehow combine ...

asked by Gabriel Landi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=347 6 votes

answered by SquareOne https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19960 3 votes

1.7.2 Greatest hits from previous weeks

   How to add a front-end to the free Wolfram Engine?
   How to express trigonometric equation in terms of of given trigonometric function?
   What’s the most difficult multidimensional integral that Mathematica has solved?
   Standard deck of 52 playing cards in curated data?
   Even Fibonacci numbers
   How do I clear all user defined symbols?
   How to perform a multi-peak fitting?

How to add a front-end to the free Wolfram Engine?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=198839

https://blog.stephenwolfram.com/2019/05/launching-today-free-wolfram-engine-for-developers/

http://www.wolfram.com/engine/

The Free Wolfram Engine for Developers is available for pre-production ...

asked by Alexey Golyshev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23402 65 votes

answered by Alexey Golyshev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23402 55 votes

How to express trigonometric equation in terms of of given trigonometric function?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=434

How can I express a trigonometric equation / identity in terms of a given trigonometric function?

using following trigonometric identities

asked by Prashant Bhate https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=99 30 votes

answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 37 votes

What’s the most difficult multidimensional integral that Mathematica has solved?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222184

I am interested in benchmarking numerical integration methods and am trying to develop a wider set of difficult multivariate examples. For my particular methods, I only want to look at non-negative-...

asked by ben18785 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19278 6 votes

Standard deck of 52 playing cards in curated data?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16108

I am not sure how to find out what all is included as curated data. For example, are the individual images of each of the 52 cards in a standard deck of playing cards included?

If not, is there a way ...

asked by JohnD https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1629 25 votes

answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 23 votes

Even Fibonacci numbers

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=37266

Today, I found the Euler Project. Problem #2 is

Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:

asked by xyz https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9627 34 votes

answered by rcollyer https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=52 46 votes

How do I clear all user defined symbols?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=850

Is there some way to do this other than going to Evaluation -> Quit kernel and firing a new one up?

asked by niklasfi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=82 99 votes

answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 98 votes

How to perform a multi-peak fitting?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=26336

I am wondering how to implement the multi-peak detecting and fitting in Mathematica. Following is an example of fitting the data using three peaks (such that the data ~ peak1 + peak2 + peak3). The ...

asked by Everett You https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1389 55 votes

answered by Silvia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=17 55 votes

1.7.3 Can you answer these questions?

   pure function assignment
   Graphics get cropped when wrapped in Hyperlink and Inset in MMA 12.2 (doesn’t seem to happen on 12.1 RPi) Bug?
   Does Mathematica have build-in function to compute dimension of square polynomial system?

pure function assignment

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=243708

I do not understand this statement from the Introduction to Dynamic tutorial:

asked by Dave https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79143 1 vote

answered by MarcoB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27951 0 votes

Graphics get cropped when wrapped in Hyperlink and Inset in MMA 12.2 (doesn’t seem to happen on 12.1 RPi) Bug?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=243637

I’ve noticed that wrapping a Graphic[] in Hyperlink[] causes weird things to happen when using ...

asked by Mike H https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79121 1 vote

Does Mathematica have build-in function to compute dimension of square polynomial system?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=243849

I’m working with square polynomial systems and wish to know if a (small) system has a finite number of solutions. That is, if it’s zero-dimensional. I’m not aware of any built-in function to do this ...

asked by Dominic https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=47466 1 vote

1.8 Thursday, March 25, 2021

  1.8.1 Top new questions this week
  1.8.2 Greatest hits from previous weeks
  1.8.3 Can you answer these questions?

1.8.1 Top new questions this week

   Head[x] vs x[[0]]?
   How to roll a graph on the y-axis
   Numerically solving Helmholtz equation in 2D for a Guitar
   How to draw the tree in a ”pitchfork” form?
   Digitizing a geometrical sensor
   How Can I Compute The Automorphism Group of a Matroid?
   How to make a circular heat map or diagram in Mathematica?

Head[x] vs x[[0]]?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=242183

Can we say Head[x] and x[[0]] are identical ? In mathematica manual I could find : ’The head is the part with index 0’

But I am not sure whether Head[x] are x[[0]] are really interchangeable in any ...

asked by imida k https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34532 15 votes

answered by Leonid Shifrin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=81 13 votes

How to roll a graph on the y-axis

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=242180

I want to roll the function f(x)=sqrt(x), x∈[0,1] along the y-axis. I know how to rotate the graph around a point, but I’m not sure how to rotate along an axis in 2D. Rotating around a point e.g. (0,...

asked by Guy Foxx https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75736 14 votes

answered by cvgmt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72111 17 votes

Numerically solving Helmholtz equation in 2D for a Guitar

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=242138

Hi I am new to using Mathematica, so am not too confident. I am essentially trying to model vibrations of a guitar sound board for a project. It would be great to get some visualisations of the ...

asked by sp96 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77970 11 votes

answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 8 votes

How to draw the tree in a ”pitchfork” form?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=242140

How to set the options or other parameters in a TreePlot to draw the branching outside of the vertex? I.e. in a form similar to a dendrogram (but the dendrogram plot itself does not support the ...

asked by Slepecky Mamut https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=48033 10 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 9 votes

Digitizing a geometrical sensor

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=242186

I want to quantify the flow from photos taken from a sensor such as this one:

For a limited number of readings, I can use a plot digitization method. However, I need to do this many times for ...

asked by MathX https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=38575 9 votes

answered by MelaGo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=63360 10 votes

How Can I Compute The Automorphism Group of a Matroid?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=242030

I want to compute the automorphism group of a matroid. This reduces to the following (more general) problem: Suppose I have a list of sets \(\{\{b_{11},\dots ,b_{1k}\},\dots ,\{b_{k1},\dots ,b_{kk}\}\}\) ...

asked by Madeline Brandt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=51040 7 votes

answered by Madeline Brandt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=51040 6 votes

How to make a circular heat map or diagram in Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=242425

Is there any way to make a circular heat map in Mathematica? Thanks for your help! Here is a toy example for regular heat map. Can anyone help me make it to a circular one?

asked by Frankie https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70269 6 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 4 votes

1.8.2 Greatest hits from previous weeks

   How can I draw the Olympic rings with Mathematica??
   Plot, extract data to a file
   What does ”Tag Integer is Protected” message mean?
   Selecting every n-th element from a list
   Labeling individual curves in Mathematica
   Help find a bright object on Mars!
   Plotting the frequency spectrum of a data series using Fourier

How can I draw the Olympic rings with Mathematica??

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8885

How can I draw the 5 interlocking Olympic rings with Mathematica? (SVG version) Edit

Hard choice, but some pretty cool answers here. I didn’t have 3D answers in mind when I posted the question, but ...

asked by Mike Honeychurch https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77 44 votes

answered by cormullion https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61 23 votes

Plot, extract data to a file

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19859

I need to save data that Mathematica uses inside the Plot command. The format that I would like to have is:

asked by molkee https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5097 30 votes

answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 47 votes

What does ”Tag Integer is Protected” message mean?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=6738

(Newbie question)

For every function I define I get this message: When I close and reopen Mathematica, and re-enter the function definition, I don’t get the message anymore. What does it mean?

asked by stevenvh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1450 11 votes

answered by J. M.’s ennui https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 13 votes

Selecting every n-th element from a list

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=64003

I have a list:

data = {4, 5, 7, 8, 9, 5, 3, 2, 1, 2, 13, 12};

I want to take those elements in the list which are located at equal distances, say, every third ...

asked by Suro https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=20003 37 votes

answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 33 votes

Labeling individual curves in Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=4444

I need to create a plot for export and inclusion in a report. Is there a better way to label curves than PlotLegends? From what I’ve read and my personal experience,...

asked by Tianxiang Xiong https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1041 63 votes

answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 47 votes

Help find a bright object on Mars!

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11819

In today’s news, scientists found a bright object on one of Curiosity’s photos (it’s near the bottom of the picture below). It’s a bit tricky to find - I actually spent quite some time staring at the ...

asked by Victor K. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1351 201 votes

answered by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 261 votes

Plotting the frequency spectrum of a data series using Fourier

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18082

testData = Table[N@Sin[500 x], {x, 0, 100}]; 
ListLinePlot[Abs[Fourier[testData]], PlotRange -> Full]

Gives me Which I do not expect because the Fourier ...

asked by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 14 votes

answered by KennyColnago https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=3246 16 votes

1.8.3 Can you answer these questions?

   Is the fancy script ’C’ mathscrC available in Mathematica?
   FormFunction output automatic download
   Generating a lattice by \(N^{th}\) iteration of unit cell

Is the fancy script ’C’ mathscrC available in Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=242074

In mathjax \mathscr{C} gives me the character \(\mathscr {C}\) that I want. There is a UTF listing for this character. https://www.compart.com/en/unicode/U+1D49E If I copy form this webpage and paste ...

asked by Steven Thomas Hatton https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44139 2 votes

FormFunction output automatic download

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=242097

I want to create a FormFunction that takes in a CSV file, applies some operations on the data and outputs another CSV file. I would like for the ouput CSV file to be automatically downloaded. I have a ...

asked by Gabriel Landi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=347 1 vote

Generating a lattice by \(N^{th}\) iteration of unit cell

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=242436

This question is in continuation of the my previous question that was not clearly presented by me at all. I have a unit cell, and I would like to generate a lattice but in iterative order. For ...

asked by L.K. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=15927 1 vote

1.9 Thursday, March 18, 2021

  1.9.1 Top new questions this week
  1.9.2 Greatest hits from previous weeks
  1.9.3 Can you answer these questions?

1.9.1 Top new questions this week

   Why am I getting that \(0.999999999999988 \geq 1.0\) is True?
   Can we make an ”Outerable” Attribute?
   How to fit a curve in a picture with an equation?
   Bug with Json payload with diacritics for HTTPRequest
   How to plot a ”main effect” plot?
   generating tuples of ones and zeroes with a fixed number of ones
   How to add an attractive potential (migration term) named component to Mass Transport PDE

Why am I getting that \(0.999999999999988 \geq 1.0\) is True?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241791

I am getting these results:

asked by Craig Carter https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12461 20 votes

answered by Chip Hurst https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4346 23 votes

Can we make an ”Outerable” Attribute?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241712

We can declare a function to have the Listable Attribute so that it automatically threads over lists in a particular way. For functions of multiple arguments it ...

asked by Tanner Legvold https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68925 14 votes

answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 8 votes

How to fit a curve in a picture with an equation?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241686

For a curve taken from a picture, is there any method to fit it with an equation if it appears to be some standard curve? For example, in the following picture, the curve looks like an ellipse or a ...

asked by Nobody https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66106 10 votes

answered by mikado https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36788 9 votes

Bug with Json payload with diacritics for HTTPRequest

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241573

Working in the creations of APIs with Mathematica 12.2, I got this problem with diacritics when sending JSON data. Here is a toy code using httpbin.

asked by Murta https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2266 10 votes

answered by Kuba https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5478 8 votes

How to plot a ”main effect” plot?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241876

I’m trying to make a ”main effect” type chart but I haven’t found a way to do it in Mathematica. The main effect plots are the graphs plotting the means for each value of a categorical ...

asked by ALEXANDRE ARARIPE https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77894 7 votes

answered by MassDefect https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42264 11 votes

generating tuples of ones and zeroes with a fixed number of ones

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241943

I would like to generate all the tuples of ones and zeros of a given length and with a given number of ones without generating all the possible tuples, which is impossible for tuples of large enough ...

asked by EGME https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53849 6 votes

answered by Roman https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26598 10 votes

How to add an attractive potential (migration term) named component to Mass Transport PDE

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241642

Wolfram Mathematica 12.2 now features ”Named Partial Differential Equation Terms”

For specific physics fields, relevant PDE terms have been packaged as components and augmented with ...

asked by rhermans https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10397 6 votes

answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 4 votes

1.9.2 Greatest hits from previous weeks

   Plotting the frequency spectrum of a data series using Fourier
   Is there something like DensityPlot3D to visualize atomic orbitals?
   xkcd-style Plots
   Generate a Unit Circle Trigonometry
   Calculate the 2D Fourier transform of an Image
   How can I plot implicit equations?
   Oak Island, extending the ”Alignment”, possible Great Circle?

Plotting the frequency spectrum of a data series using Fourier

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18082

testData = Table[N@Sin[500 x], {x, 0, 100}]; 
ListLinePlot[Abs[Fourier[testData]], PlotRange -> Full]

Gives me Which I do not expect because the Fourier ...

asked by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 14 votes

answered by KennyColnago https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=3246 16 votes

Is there something like DensityPlot3D to visualize atomic orbitals?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=32378

I’m visualizing some hydrogen like atomic orbitals. For looking at plane slices of the probability density, the DensityPlot function works well, and with something ...

asked by Peeter Joot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10 45 votes

answered by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 25 votes

xkcd-style Plots

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11350

I received an email to which I wanted to respond with a xkcd-style graph, but I couldn’t manage it. Everything I drew looked perfect, and I don’t have enough command over ...

asked by Amatya https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2039 622 votes

answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 483 votes

Generate a Unit Circle Trigonometry

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2456

Struggling often with Trigonometry I would like to have some code to generate this Unit Circle Trigonometry. Would be of great help when I need to transform some data :

asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 18 votes

answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 32 votes

Calculate the 2D Fourier transform of an Image

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=29203

I am new to Mathematica, and using version 8.0.

I would like to calculate the 2D Fourier Transform of an Image with Mathematica and plot the magnitude and phase ...

asked by user8727 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8727 17 votes

answered by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 33 votes

How can I plot implicit equations?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=34668

If you enter the following into Wolfram Alpha, you get nice graphs:

graph 4 x^4 + y^2 = 2 

How do you do this in Mathmatica? I realize that these are not ...

asked by Rollie https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10174 39 votes

answered by Timothy Wofford https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9391 40 votes

Oak Island, extending the ”Alignment”, possible Great Circle?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235815

During these days of COVID, I indulged in the guilty pleasure of watching The Curse of Oak Island - Season 8, Episode 4 Alignment, which viewed last night (1 Dec 2020). During the episode, some ”...

asked by Jagra https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=571 13 votes

answered by Carl Lange https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57593 12 votes

1.9.3 Can you answer these questions?

   ColorFunction in ListContourPlot3D raising error when using more than one argument
   Autocomplete file argument for custom function
   Reduce the time to find six integer numbers so that the angle of two vectors equal to Pi/6

ColorFunction in ListContourPlot3D raising error when using more than one argument

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241851

The documentation of ColorFunction states that in ListContourPlot3D your chosen function gets the arguments ...

asked by Fidel I. Schaposnik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45839 1 vote

Autocomplete file argument for custom function

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241842

When typing Importin a notebook Mathematica suggests to autocomplete the file path you want to enter or choose a file using the GUI. Is there a way to let a ...

asked by Gert https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27889 1 vote

Reduce the time to find six integer numbers so that the angle of two vectors equal to Pi/6

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241633

I am trying to find six integer numbers a, b, c, x, y, z so that the angle of two vector {a, b, c ...

asked by minhthien_2016 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5320 1 vote

answered by Daniel Huber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46318 0 votes

1.10 Thursday, March 11, 2021

  1.10.1 Top new questions this week
  1.10.2 Greatest hits from previous weeks
  1.10.3 Can you answer these questions?

1.10.1 Top new questions this week

   Metropolis-Hastings Algorithm - Significantly slower than Python
   Manipulate for playing along with ”Deal or No Deal?”
   BoxWhiskerChart - how to show Quartile and other values
   Strictly Increasing Sequences of Length n in a List
   Wafer Chucking Model
   Art on Mathematica: How can I export 4K resolution png images?
   Skewed grid in plot

Metropolis-Hastings Algorithm - Significantly slower than Python

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241402

I would like to code a Metropolis Hasting algorithm and thought I would get the general scheme of things going with a toy example.

I think I got it running but my Mathematica code runs significantly ...

asked by Smerdjakov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=55615 13 votes

answered by Henrik Schumacher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=38178 22 votes

Manipulate for playing along with ”Deal or No Deal?”

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241234

I started building this Manipulate and am certain I can do so on my own, but thought it was fun enough that others might want to try. (If this is some abuse of the ...

asked by David G. Stork https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9735 9 votes

BoxWhiskerChart - how to show Quartile and other values

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241231

I have a question in respect of the BoxWhiskerChart. The default functionality of BoxWhiskerChart is that you mouse over it and ...

asked by Jiri https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77351 9 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 9 votes

Strictly Increasing Sequences of Length n in a List

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241087

I need to determine how many strictly increasing sequences of a certain length (e.g. 5) are contained in a list of integers. I would be very happy if someone could help me. A sequence would be ...

asked by hnh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77559 9 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 9 votes

Wafer Chucking Model

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241086

I am trying to calculate the pressure required to flatten a bowed wafer. The simple model I am using for the study has a bottom layer (the bowed wafer) pushed against a harder flat surface as shown in ...

asked by martin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77626 8 votes

answered by user21 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18437 2 votes

Art on Mathematica: How can I export 4K resolution png images?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241503

This question is solely based upon \([1]\) and therefore, the reading of \([1]\) could be interesting. How can I export the image created, by the code in the following, with high definition, beautiful, 4K ...

asked by M.N.Raia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=71570 8 votes

answered by thorimur https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=63584 10 votes

Skewed grid in plot

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241405

Is is possible to add a skewed grid in a plot? Consider the following image;

The grey axes are the normal axes (\(\mathbf {e}_1\) and \(\mathbf {e}_2\)), the black axes are transformations \(\mathbf {e}'_1=2\)

asked by mf67 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=55498 8 votes

answered by Daniel Huber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46318 8 votes

1.10.2 Greatest hits from previous weeks

   Mathematica vs. Python - how does Mathematica compare to Python’s scientific computing suite?
   Exporting graphics to PDF - huge file
   How do I plot a plane EM wave?
   How to create animated snowfall?
   Image processing: Floor plan - detecting rooms’ borders (area) and room names’ texts
   Calculate the 2D Fourier transform of an Image
   What are the most common pitfalls awaiting new users?

Mathematica vs. Python - how does Mathematica compare to Python’s scientific computing suite?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=86058

Python’s family of packages for scientific computing has matured rapidly. I can pretty much replicate all of Mathematica’s functionalities, but with production level and open-source code using the ...

asked by M.R. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=403 49 votes

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 36 votes

Exporting graphics to PDF - huge file

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=1542

I want to draw some basic surfaces, export them to PDF and include them in a LaTeX file. I create a simple 3D graphics object, for instance with

asked by Matthew Leingang https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=395 109 votes

answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 88 votes

How do I plot a plane EM wave?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=1987

I would like to display an electromagnetic (EM) wave. I have written code that works, but it does not ”shade” the area between the graph and the axes. Both the ...

asked by Rainforest Frog https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=202 22 votes

answered by J. M.’s ennui https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 16 votes

How to create animated snowfall?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16881

Well, the title is self-explanatory. What sorts of snowfall can we generate using Mathematica? There are two options I suggest to consider:

1) Continuous GIF animations with smallest possible number ...

asked by faleichik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=219 40 votes

answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 54 votes

Image processing: Floor plan - detecting rooms’ borders (area) and room names’ texts

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19546

Here is a simple building floor plan. I would like to derive the rooms as (rectangular) components and the names of the rooms. This is very common representation of building floor plans.

The problem

asked by s.s.o https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=840 64 votes

answered by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 59 votes

Calculate the 2D Fourier transform of an Image

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=29203

I am new to Mathematica, and using version 8.0.

I would like to calculate the 2D Fourier Transform of an Image¡ with Mathematica and plot the magnitude and phase ...

asked by user8727 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8727 17 votes

answered by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 33 votes

What are the most common pitfalls awaiting new users?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18393

As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...

asked by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 482 votes

answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 288 votes

1.10.3 Can you answer these questions?

   Front-end rendering issues on Linux
   time series - minimum differencing order needed to remove the trend
   How does ‘TextureCoordinateFunction[]‘ works within ‘SurfaceAppearance[]‘?

Front-end rendering issues on Linux

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241216

I’m using Mathematica 12.2 on Ubuntu Mate 20.10 on an AMD FX(tm)-8120 with a GeForce GTX 1070 Ti NVIDA card. The issue is that I get unwanted horizontal lines just below the cell that I’m working on ...

asked by c186282 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4515 1 vote

time series - minimum differencing order needed to remove the trend

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241097

I was wondering how can I find What is the minimum differencing order needed to remove the trend in a time series? I have a a times series and a TimeSeriesModelFit, which is SARIMA model. I want to ...

asked by Pjana https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75643 1 vote

How does ‘TextureCoordinateFunction[]‘ works within ‘SurfaceAppearance[]‘?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241245

Following up from @kglr's answer here, I’d like to understand how TextureCoordinateFunction[] works within SurfaceAppearance[]. ...

asked by martin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9923 1 vote

1.11 Thursday, February 25, 2021

  1.11.1 Top new questions this week
  1.11.2 Greatest hits from previous weeks
  1.11.3 Can you answer these questions?

1.11.1 Top new questions this week

   Mathematica 12.1: Don’t use Accumulate or Differences on Around objects!
   How to enter a repeating decimal in Mathematica
   How to judge whether two groups of sequences are equal in cycles?
   Simplify 1+Sqrt[2]I-Complex[1,Sqrt[2]]
   How to correctly calculate the number of seating plans for the 4-couples problem?
   How to approximate \(PV\int _0^\infty \frac {\tan x}{x}\text {d}x?\)
   Mirror image of graph

Mathematica 12.1: Don’t use Accumulate or Differences on Around objects!

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240449

SUMMARY: If a List,TimeSeries etc. of Around objects contains any identical elements,

asked by Aaron Eiben https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72186 14 votes

answered by Sjoerd Smit https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=43522 11 votes

How to enter a repeating decimal in Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240596

I don’t understand how to manipulate numbers with repeating decimal in Wolfram Mathematica language. For example 0.3... does not work as input and I don’t see how ...

asked by Simpleton Jack https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=22399 9 votes answered by J. M.’s ennui https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 11 votes

How to judge whether two groups of sequences are equal in cycles?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240325

There’s a set of arrays that I want to remove repeated elements that are equal after rotation:

asked by A little mouse on the pampas https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42417 9 votes

answered by Carl Woll https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45431 11 votes

Simplify 1+Sqrt[2]I-Complex[1,Sqrt[2]]

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240522

The expression 1+Sqrt[2]I-Complex[1,Sqrt[2]] should be zero. In fact, N[1+Sqrt[2]I-Complex[1,Sqrt[2]]] yields ...

asked by pdmclean https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9154 7 votes answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 10 votes

How to correctly calculate the number of seating plans for the 4-couples problem?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240357

Four couples a are sitting around a round table, in which husband and wife can not be adjacent. How many different seating plans are there? I want to get as many simple calculations as possible.

asked by A little mouse on the pampas https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42417 7 votes

answered by Beny Izd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77079 8 votes

How to approximate \(PV\int _0^\infty \frac {\tan x}{x}\text {d}x?\)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240461

What’s the mathematica command to get the numerical value of :

   ∫  ∞ tanx
PV      --x--dx?
     0

where \(PV\) is the principal value.

asked by Ali Shadhar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=67714 7 votes

answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 7 votes

Mirror image of graph

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240571

I need to display a directed acyclic graph (say Hasse diagram of partial order) oriented with minimal elements at the bottom, maximal elements at the top as is conventional for Hasse diagrams. I tried ...

asked by Mike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=62210 6 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes

1.11.2 Greatest hits from previous weeks

   LaTeX and Mathematica
   What’s the most difficult multidimensional integral that Mathematica has solved?
   xkcd-style Plots
   Finding Limits in several variables
   How to use Mathematica functions in Python programs?
   Plot data from txt file?
   How to find integer solutions?

LaTeX and Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=736

I quite often would like to draw graphics in my LaTeXdocuments using Mathematica. I have encountered three problems. I would like to know if there are any workarounds to these problems

I would ...

asked by Thomas Rot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=227 127 votes

answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 46 votes

What’s the most difficult multidimensional integral that Mathematica has solved?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222184

I am interested in benchmarking numerical integration methods and am trying to develop a wider set of difficult multivariate examples. For my particular methods, I only want to look at non-negative-...

asked by ben18785 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19278 6 votes

xkcd-style Plots

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11350

I received an email to which I wanted to respond with a xkcd-style graph, but I couldn’t manage it. Everything I drew looked perfect, and I don’t have enough command over ...

asked by Amatya https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2039 620 votes

answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 481 votes

Finding Limits in several variables

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=21544

Is there a way to find a limit of a multivariable function, like

   lim    f(x,y)
(x,y)→ (0,0)

with Mathematica?

When \(f\) is continuous, we can use

(x,yl)im→(0,0)f(x,y) =

asked by Dominic Michaelis https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5899 31 votes

answered by whuber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=91 42 votes

How to use Mathematica functions in Python programs?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=4643

I’d like to know how can I call Mathematica functions from Python.

I appreciate a example, for example, using the Mathematica function Prime.

I had search about MathLink but how to use it in Python ...

asked by GarouDan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1058 69 votes

answered by GarouDan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1058 28 votes

Plot data from txt file?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=5910

I have data in file.txt which can be expressed by 20000x11 matrix. I do not want to import all of these data. How can I plot graph of the column 1 & column 4?

asked by Gokce https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1297 21 votes

answered by user1066 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=106 24 votes

How to find integer solutions?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=42359

Following is the equation: Need to solve for integer values of x,y when a,b lies between -1000 and 1000. Problem is to find the number of integer values of pair (x,y) that satisfy it.

asked by Sahil Sareen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12396 2 votes

answered by bill s https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1783 4 votes

1.11.3 Can you answer these questions?

   Idiomatic pattern for subtracting a function from a list
   How can I simplify a symbolic tensor expression?
   Nothing showing up on my LogLogPlots

Idiomatic pattern for subtracting a function from a list

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240468

I would like to know a more idiomatic way to subtract a function from a list of pairs than this: Table[point-{0,fitFunction[point[[1]]]}, {point,data}]

I use this ...

asked by Diffycue https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46327 1 vote

How can I simplify a symbolic tensor expression?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240422

My question is about simplifying tensor expressions. If I have \((a+b)\otimes (c+d)\) The function TensorExpand gives \(a\otimes c + a\otimes d + b\otimes c + b\otimes \) ...

asked by Physor https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74507 2 votes

Nothing showing up on my LogLogPlots

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240457

I am trying to make 2 log log plots. One with each equation, a and g. I don’t know why, but the plot is not showing up. My notebook is in the link below. https://imgur.com/a/sXQX0YS

What am I doing ...

asked by QuaffyWaffles https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77475 1 vote

answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 0 votes

1.12 Thursday, February 18, 2021

  1.12.1 Top new questions this week
  1.12.2 Greatest hits from previous weeks
  1.12.3 Can you answer these questions?

1.12.1 Top new questions this week

   How to create a spiral using Golden Triangles
   How to modify default options of Dataset
   How to use Filling in PolarPlot?
   How to reduce timing to find the integer numbers a, b, c, d, e, f, g, h, k, m of this equation?
   How to extract a column (or a row) of a matrix as another column vector/ column matrix (or a row vector), not as a list?
   Intuitive explanation of RemoteBatchSubmit[] in AWS for total novices?
   Solving a 2D heat equation on a square with Dirichlet boundary conditions

How to create a spiral using Golden Triangles

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239914

Working with students in a pre-calculus class, an application of the sine law. They are working on a question that has them create a Golden Triangle (A golden triangle is an isosceles triangle in ...

asked by Tom De Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=721 14 votes

answered by J. M.’s ennui https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 14 votes

How to modify default options of Dataset

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239960

I try to make a dark stylesheet based on the ReverseColor theme. However, dataset headers are barely readable.

This question is related to others such as Question ...

asked by Vly https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=47700 9 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 8 votes

How to use Filling in PolarPlot?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239946

For example: PolarPlot[{1, 1 + 1/10 Sin[10 t]}, {t, 0, 2 Pi}]

how to fill color in the space between 2 functions?

asked by DORA https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74396 8 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 11 votes

How to reduce timing to find the integer numbers a, b, c, d, e, f, g, h, k, m of this equation?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239874

I use by hand to get this result

┌│  ------------∘---------------------------------------||
│         --|           --|  ∘ ---------|--∘---------||           -|
∘  48+ 5√ 3 +    27+ 4 √3  +   12+ 3 √3  +   4+  2√3     = 1 + 4√ 3

asked by minhthien_2016 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5320 7 votes

answered by yarchik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9469 6 votes

How to extract a column (or a row) of a matrix as another column vector/ column matrix (or a row vector), not as a list?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240123

Suppose I have a matrix ’mat’ as

mat = Table[Subscript[m, i, j], {i, 5}, {j, 5}]; 
mat // MatrixForm

I want to extract the first column (or any row) as

asked by PoreyS https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=54258 6 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 6 votes

Intuitive explanation of RemoteBatchSubmit[] in AWS for total novices?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240149

When I read Wolfram’s post about the new features in MMA 12.2 I was intrigued by RemoteBatchSubmit[]. He wrote:

I have only ever used MMA from my laptop, and never used any other cloud computing or ...

asked by TumbiSapichu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53229 6 votes

Solving a 2D heat equation on a square with Dirichlet boundary conditions

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240090

I am trying to solve the following heat equation problem on the square [0,1]x[0,1]. 
\begin{equation*}  \begin{gathered}  u_t = u_{xx} + u_{yy} + f(x,y,t), \qquad  u(x,y,0) = 0, \qquad  u=0 \text{ on ...

asked by kroner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77278 6 votes

answered by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 7 votes

1.12.2 Greatest hits from previous weeks

   Crack CAPTCHA using deep learning
   How to make an inkblot?
   Generate a Unit Circle Trigonometry
   Exporting graphics to PDF - huge file
   How to make the digits of π go around in a spiral like this?
   How to create a new ”person curve”?
   How do I plot a plane EM wave?

Crack CAPTCHA using deep learning

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=143691

Deep convolutional neural networks are very good at computer vision related tasks. Optical Character Recognition (OCR) is one important branch of computer vision. In fact, the convolution neural ...

asked by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 88 votes

answered by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 98 votes

How to make an inkblot?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3345

How to effectively create a polygon that looks like a realistic inkblot? So far, I could come up with this (borrowing from Ed Pegg Jr.’s Rorschach demonstration):

asked by István Zachar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 86 votes

answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 51 votes

Generate a Unit Circle Trigonometry

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2456

Struggling often with Trigonometry I would like to have some code to generate this Unit Circle Trigonometry. Would be of great help when I need to transform some data :

asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 18 votes

answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 32 votes

Exporting graphics to PDF - huge file

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=1542

I want to draw some basic surfaces, export them to PDF and include them in a LaTeX file. I create a simple 3D graphics object, for instance with

asked by Matthew Leingang https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=395 109 votes

answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 88 votes

How to make the digits of π go around in a spiral like this?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=109982

Here is a start.

MapIndexed[Text[Reverse[First[RealDigits[Pi,10,252]]][[Tr@#2]],#]&, 
 Table[{t Cos[t],t Sin[t]},{t,0,16Pi,0.2}]]//Graphics

asked by matrix89 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5379 57 votes

answered by Martin Ender https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2305 73 votes

How to create a new ”person curve”?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=17704

Wolfram—Alpha has a whole collection of parametric curves that create images of famous people. To see them, enter WolframAlpha["person curve"] into a Mathematica ...

asked by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 85 votes

answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 45 votes

How do I plot a plane EM wave?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=1987

I would like to display an electromagnetic (EM) wave. I have written code that works, but it does not ”shade” the area between the graph and the axes. Both the ...

asked by Rainforest Frog https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=202 22 votes

answered by J. M.’s ennui https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 16 votes

1.12.3 Can you answer these questions?

   Unpacking list of arguments into parameters
   Can one preset credentials for ServiceConnect[”Twitter”, ”New”] to allow wolframscript headless use?
   Warnings while solving a system of coupled differential equations

Unpacking list of arguments into parameters

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240016

I have a list in the following form:  list = {{a,1,3},{b,1,3},{c,1,3}}

Now I want to apply this list as parameters for the Sum function so that I end up with the ...

asked by Hell stormer https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77333 1 vote

Can one preset credentials for ServiceConnect[”Twitter”, ”New”] to allow wolframscript headless use?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240056

Trying to run some wolframscript code from a server, is it possible to set ServiceConnect credentials in the environmental variables for example?

asked by Tim https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=416 3 votes

Warnings while solving a system of coupled differential equations

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239861

I have a system of differential equations, given by

asked by No name https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69573 1 vote

1.13 Thursday, February 11, 2021

  1.13.1 Top new questions this week
  1.13.2 Greatest hits from previous weeks
  1.13.3 Can you answer these questions?

1.13.1 Top new questions this week

   Mathematica cannot seem to properly handle times in the 1 hour before clocks go back
   Dataset Association of Association vs Hierarchical data
   Plot many curves on the same graph
   Is there any other way to access the n-th element of a BlankSequence?
   Periodic von Neumann neighbours
   Equivalent of numpy’s newaxis
   Plot[Im[f[x]],...] incorrectly gives graph of identical zero function

Mathematica cannot seem to properly handle times in the 1 hour before clocks go back

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239480

Using Chicago as an example; According to the current rules for applying daylight saving time, at 02:00:00 on the first Sunday of November, clocks in Chicago go back 1 hour (from Central Daylight Time ...

asked by RobertNathaniel https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=60404 24 votes

answered by Patrick Stevens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=30771 22 votes

Dataset Association of Association vs Hierarchical data

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239455

I have the following dataset:

asked by Whelp https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1287 10 votes

answered by WReach https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=142 13 votes

Plot many curves on the same graph

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239609

This plot has 40 curves on the same graph which makes it hard to see. I need to plot them on one graph. So I have an idea to plot to make it easier to see which one is larger or smaller in each range....

asked by anhnha https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18805 9 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 21 votes

Is there any other way to access the n-th element of a BlankSequence?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239659

Consider a named BlankSequence x__. How can I access the n-th element? 
Is {x}[[n]] the only ...

asked by Money Oriented Programmer https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42141 8 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 10 votes

Periodic von Neumann neighbours

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239512

From Carl Woll’s answer here, I have this code for pulling the von Neumann neighbors:

asked by TubularHell https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76599 8 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 6 votes

Equivalent of numpy’s newaxis

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239518

Numpy has a newaxis object that allows you to insert a new dimension of length 1 into an array. So after ...

asked by Dan Piponi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13642 8 votes

answered by swish https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2490 8 votes

Plot[Im[f[x]],...] incorrectly gives graph of identical zero function

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239728

Consider

Plot[Im[(1 + (-1)^(2/3)*x)/((-1)^(2/3) + x)], {x, 0, 1}]

At least in Mma 11 it gives the following picture: Meanwhile,

asked by Roma Lee https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57495 7 votes

1.13.2 Greatest hits from previous weeks

   How to create animated snowfall?
   Calling Correct Function for Plotting DiracDelta
   How to manipulate 2D plots?
   Using Export[] sends the file where?
   How can I reproduce this mandala with Mathematica?
   Mathematica Minecraft
   Plotting the frequency spectrum of a data series using Fourier

How to create animated snowfall?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16881

Well, the title is self-explanatory. What sorts of snowfall can we generate using Mathematica? There are two options I suggest to consider:

1) Continuous GIF animations with smallest possible number ...

asked by faleichik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=219 40 votes

answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 54 votes

Calling Correct Function for Plotting DiracDelta

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3506

I am wondering what is the correct function in Mathematica to plot the true impulse function, better known as the DiracDelta[] function. When using this inside of a ...

asked by night owl https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=116 17 votes

answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 19 votes

How to manipulate 2D plots?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=7142

When it comes to visual analysis, large datasets or data with intricate internal details often makes plotting in 2D useless, as the outcome is either just a fraction of the full dataset, or no details ...

asked by István Zachar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 137 votes

answered by IstvánZacharhttps://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 155 votes

Using Export[] sends the file where?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8586

I am trying to use the Export command to convert a list of plots into a *.gif file, and the command runs and executes well, but I can’t find the file! Where is it ...

asked by Patrick Da Silva https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1785 37 votes

answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 51 votes

How can I reproduce this mandala with Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233050

I found this image on the Internet and it is very beautiful. How can I reproduce it? The ideal would be to be able to control the colors of the outside as well as the center.

asked by Susana https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=37778 14 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 35 votes

Mathematica Minecraft

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19669

Some time ago I asked myself: with all these great graphics and interactive capabilities of Mathematica, what kinds of 3D games can be implemented in it? And the answer which came to mind is ...

asked by faleichik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=219 167 votes

answered by faleichikhttps://mathematica.stackexchange.com/landing/r/digest?cta=user&id=219 241 votes

Plotting the frequency spectrum of a data series using Fourier

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18082

testData = Table[N@Sin[500 x], {x, 0, 100}]; 
ListLinePlot[Abs[Fourier[testData]], PlotRange -> Full]

Gives me Which I do not expect because the Fourier ...

asked by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 14 votes

answered by KennyColnago https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=3246 16 votes

1.13.3 Can you answer these questions?

   Fourier transform in polar coordinates using built-in hankel transform of the function constant 1
   Exponent combinations
   Plot derivative of a real function consisting of a complex function

Fourier transform in polar coordinates using built-in hankel transform of the function constant 1

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239754

Like in the table of transforms https://en.wikipedia.org/wiki/Fourier_transform#Distributions,_one-dimensional the FT (Fourier transform) of \(\delta \) is 1 and the FT of 1 is \(\delta \), but in polar ...

asked by user740332 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76926 1 vote

Exponent combinations

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239664

How can I have Mathematica represent the product of two different bases and exponents as a single power (where possible)? For example, see the product below can be expressed below:

asked by Steve237 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69429 1 vote

Plot derivative of a real function consisting of a complex function

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239796

I obtained the data for the real and imaginary parts of a complex function \(A(x,t)=A_r(x,t)+i A_i(x,t)\) from NDSolve, both are functions of time \(t\) and space \(x\). ...

asked by Enter https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19178 1 vote

1.14 Thursday, February 4, 2021

  1.14.1 Top new questions this week
  1.14.2 Greatest hits from previous weeks
  1.14.3 Can you answer these questions?

1.14.1 Top new questions this week

   Confirm vs Throw
   How to use wolframscript to develop flexible command-line tools?
   Automatic Method for FindMinimum with constraints
   How to refine a boundary mesh with MeshRefinementFunction?w
   Ugly streaks caused by Arg in a contour plot
   Trying to Rotate the North Pole View of a Globe
   problem with DelaunayMesh 3D coordinates

Confirm vs Throw

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239250

Version 12.2 brought us Confirm and Enclose. What’s the point? Is it just that it’s a slightly more convenient syntax than ...

asked by Patrick Stevens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=30771 13 votes

How to use wolframscript to develop flexible command-line tools?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239072

I am currently changing a notebook into a wolframscript for a ”production” environment, where I plan to pack the script as a standard CLI tool. However I do not know how to implement such an ...

asked by Gravifer https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72025 10 votes

Automatic Method for FindMinimum with constraints

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238999

What is the default method used by FindMinimum with constraints? The documentation says:

”Currently, the only method available for constrained optimization is ...

asked by VarunM https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69094 9 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 8 votes

How to refine a boundary mesh with MeshRefinementFunction?w

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239220

MeshRefinementFunction works well to refine elements in a defined spatial domain (here \(x>0\)):

asked by Oscillon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13605 8 votes

answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 8 votes

Ugly streaks caused by Arg in a contour plot

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239255

I had a more general question about a similar problem more than two years ago, Getting rid of discontinuities in plots caused by square roots, logarithms, ‘Arg‘, etc, which got lots of interesting ...

asked by მამუკა ჯიბლაძე https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=35000 8 votes

answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 11 votes

Trying to Rotate the North Pole View of a Globe

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239294

My goal is to generate diagrams like this.

But I would like to be able to rotate the globe about the North Pole, so that I can represent different times of the day. When I use ImageRotate, the ...

asked by David Elm https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44449 7 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 11 votes

problem with DelaunayMesh 3D coordinates

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239303

I found DelaunayMesh works fine for 2D. For example,

asked by matheorem https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4742 7 votes

answered by user21 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18437 7 votes

1.14.2 Greatest hits from previous weeks

   Conversion of Sine to Cosine
   Extract real part of a complex expression better than Re does
   Assign the results from a Solve to variable(s)
   Why round to even integers?
   Using Export[] sends the file where?
   Formatting legend text font
   What do the X and Y axis stand for in the Fourier transform domain?

Conversion of Sine to Cosine

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=67521

I’m solving equations with many Cosines and Sines. And I want to convert all the Sines to Cosines using trigonometric formulas such as cos(x)=sin(x+pi/2). How can I do this?

asked by YongCheol Kwon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23041 4 votes

answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 2 votes

Extract real part of a complex expression better than Re does

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3306

I have a complex expression with real positive variables only.

Mathematica Input Style:

asked by max https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=796 34 votes

answered by nixeagle https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=814 53 votes

Assign the results from a Solve to variable(s)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=6669

I understand Mathematica can’t assign the results of a Solve to the unknowns because there may be more than 1 solution. How can I assign the 4 values of following result to variables?

asked by stevenvh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1450 56 votes

answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 34 votes

Why round to even integers?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2116

According to the Mathematica help: Round rounds numbers of the form x.5 toward the nearest even integer. For example:

Round[{0.5, 1.5, 2.5, 3.5, 4.5}]

gives

asked by wxffles https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=427 83 votes

answered by Per Alexandersson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=488 51 votes

Using Export[] sends the file where?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8586

I am trying to use the Export command to convert a list of plots into a *.gif file, and the command runs and executes well, but I can’t find the file! Where is it ...

asked by Patrick Da Silva https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1785 37 votes

answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 51 votes

Formatting legend text font

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3433

I am using this code to plot a graph, and I am trying to make the font of the legend bigger.

asked by Julia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=525 20 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 25 votes

What do the X and Y axis stand for in the Fourier transform domain?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=85139

In Wolfram Mathematica the function Fourier has the following declaration

Fourier[list]

And after a list is given to the ...

asked by user253956 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29958 27 votes

answered by Hugh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12558 61 votes

1.14.3 Can you answer these questions?

   RegionPlot of the Maximum of a function
   How to let Mathematica evaluate a large amount of data
   Directed Infinity vs Indeterminant in this output

RegionPlot of the Maximum of a function

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239047

For the function fun[a_, b_, x_, y_] = Sin[a x] Cos[b y] (a x + b y); corresponding to \(x\) and \(y\), I need a RegionPlot showing the maximum of function \(fun[a, b, x]\)

asked by Mike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76947 1 vote

answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 0 votes

How to let Mathematica evaluate a large amount of data

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239107

I have the following code in mathematica which runs perfectly for a small matrix of 21 x 12 matrix. But I really want to test it for a large system. My data is 35844 x 21000 elements, totaling 1.5 GB. ...

asked by shixx597_Min https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=59772 1 vote

Directed Infinity vs Indeterminant in this output

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239335

When I evaluate

asked by user824530 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75136 1 vote

1.15 Thursday, January 28, 2021

  1.15.1 Top new questions this week
  1.15.2 Greatest hits from previous weeks
  1.15.3 Can you answer these questions?

1.15.1 Top new questions this week

   What’s the difference between these 2 associations?
   How can I handle graphics or artworks with millions of points?
   ContourPlot3D, grid of cylinders
   Distorting image to ensure consistent vanishing point
   Export infinite looping GIFs by default
   Replace a color in image with hatchfilling
   MeshRefinementFunction on 2D surfaces embedded in 3D

What’s the difference between these 2 associations?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238880

I have 2 associations similar to these simplified ones:

asked by Coolwater https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9754 16 votes

answered by Leonid Shifrin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=81 16 votes

How can I handle graphics or artworks with millions of points?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238735

As a hobby, I am trying to use Mathematica and Wolfram Language as a tool for making generative artworks. Generative art techniques may require drawing millions of points, lines, or curves. For ...

asked by mikabozu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74721 15 votes

answered by George Varnavides https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=41179 21 votes

ContourPlot3D, grid of cylinders

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238849

I am trying to make a 3D contour plot that looks like a grid of cylinders to represent the Fermi surface of a metal, like below:

I have no problem generating something that kind of looks like it.

asked by Nick https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76998 10 votes

answered by cvgmt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72111 13 votes

Distorting image to ensure consistent vanishing point

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238742

Here’s Giorgio de Chirico’s painting, Ariadne:

The Surrealist artist deliberately broke the rules of geometric perspective, giving the work his characteristic sense of mystery and unease. What would ...

asked by David G. Stork https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9735 10 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 2 votes

Export infinite looping GIFs by default

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238591

frames=Table[Plot[Sin[x(1+a x)],{x,0,6}],{a,0,2,0.2}]; 
Export["test.gif",frames]

The above code runs in version 9.0 to get a infinite looping GIF ...

asked by expression https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7339 10 votes

answered by Kuba https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5478 7 votes

Replace a color in image with hatchfilling

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238687

Is it possible to identify a color (say grey in a 3 color Black, Gray and White image) and ...

asked by skyfire https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70181 9 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 10 votes

MeshRefinementFunction on 2D surfaces embedded in 3D

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238705

DiscretizeRegion doesn’t seem to run the supplied MeshRefinementFunction when meshing a 2D surface in 3D. For example:

asked by alessandro https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42454 7 votes

answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 3 votes

1.15.2 Greatest hits from previous weeks

   How do I identify the source of a ”Tag times protected” error?
   Labeling individual curves in Mathematica
   How to add a vertical line to a plot
   Drawing a square root spiral
   Multivariable Taylor expansion does not work as expected
   Solving \(L=\frac {3}{2} \sqrt {4 \pi ^2 A^2+W^2}-\frac {\sqrt {5 W \sqrt {4 \pi ^2 A^2+W^2}+6 \pi ^2 A^2+3 W^2}}{\sqrt {2}}+\frac {3 W}{2}\) for \(W\)
   Mathematica command that allows it to read my intentions

How do I identify the source of a ”Tag times protected” error?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11982

I have some code that looks like

Table[ 
    a = 1; 
    b = {2, 3} 
    c = i;, 
    {i, 2} 
] 
 
which gives an error: 
  Set::write: Tag Times in c {2,3} is Protected....

asked by dearN https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=204 29 votes

answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 35 votes

Labeling individual curves in Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=4444

I need to create a plot for export and inclusion in a report. Is there a better way to label curves than PlotLegends? From what I’ve read and my personal experience,...

asked by Tianxiang Xiong https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1041 63 votes

answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 47 votes

How to add a vertical line to a plot

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3561

In the plot below I would like to add two vertical lines at \(x = \frac {\pi }{15} \pm \frac {1}{20}\). How can I do that?

asked by sjdh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=515 61 votes

answered by Ajasja https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=745 82 votes

Drawing a square root spiral

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=66969

Here is a start. I’m looking for a nice way to draw it.

asked by matrix89 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5379 24 votes

answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 21 votes

Multivariable Taylor expansion does not work as expected

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=15023

The basic multivariable Taylor expansion formula around a point is as follows:

asked by matheorem https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4742 63 votes

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 71 votes

Solving \(L=\frac {3}{2} \sqrt {4 \pi ^2 A^2+W^2}-\frac {\sqrt {5 W \sqrt {4 \pi ^2 A^2+W^2}+6 \pi ^2 A^2+3 W^2}}{\sqrt {2}}+\frac {3 W}{2}\) for \(W\)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=57763

When I solve the aforementioned equation for \(W\) or \(A\) on Mathematica I get a long and ugly equation in return, namely one of the solutions for \(W\) is: (attempt to read at your own health)

asked by J.D’Almbert https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19257 8 votes

answered by Alexei Boulbitch https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=788 15 votes

Mathematica command that allows it to read my intentions

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=194384

In version 2.0 of Mathematica there was a command, ReadProgrammerIntentions[ ] which allowed it rapidly compose code that could solve problems simple to complex, ...

asked by MikeY https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=47314 52 votes

answered by MarcoB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27951 38 votes

1.15.3 Can you answer these questions?

   How to improve this code?
   Error on DSolve
   Remove defect of display in ListDensityPlot3D

How to improve this code?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238887

The aim of my work is to find a value for the complex constant \(\omega \). In order to do that I solve the below system of differential equations with a manual shooting method: I first solve the system ...

asked by mattiav27 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8822 3 votes

Error on DSolve

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238596

I’ve been trying to solve this initial value problem using DSolve[]:

dy
-dt = 1+ tsin(ty),  y(0) = 0,  t = [0,2]

asked by Walser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=60465 1 vote

answered by Mariusz Iwaniuk https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26828 0 votes

Remove defect of display in ListDensityPlot3D

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238719

I have a 3D volumetric data (for example, \(64\times 64\times 64\), at each point there is a value) read in from a file and I want to use ListDensityPlot3D to ...

asked by Dennis https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69969 1 vote

1.16 Thursday, January 21, 2021

  1.16.1 Top new questions this week
  1.16.2 Greatest hits from previous weeks
  1.16.3 Can you answer these questions?

1.16.1 Top new questions this week

   How can I use Mathematica to solve a complex truth-teller/liar logic problem?
   list-array construction
   why do these two Meijer G functions not cancel each other?
   How to partition a square into successive halves
   Ignoring fractions can lead to correct answer
   Context Manipulation within Scoping Constructs
   Why does NMinimize not follow MaxIterations?

How can I use Mathematica to solve a complex truth-teller/liar logic problem?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238461

I have a logic puzzle I want to convert to Mathematica to solve: Person A states, ”Exactly two people are truth-tellers,” Person B states, ”I and Person C are truth-tellers.”

asked by Peter Burbery https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76873 16 votes

answered by SneezeFor16Min https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69875 19 votes

list-array construction

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238293

I want to create the list ix={1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4} I can do

asked by geom https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68502 11 votes

answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 20 votes

why do these two Meijer G functions not cancel each other?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238321

I encountered such expressions in Mathematica MeijerG[{{ }, {1, c + 1/2}}, {{0, c, c, c}, { }}, 1] + MeijerG[{{1}, {c + 1/2}},    {{c, c, c},    {0}}, 1]

which in ...

asked by Jing https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76801 8 votes

answered by Chromo Runge https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68326 12 votes

How to partition a square into successive halves

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238440

I am teaching the idea of infinite geometric series to high school students, looking for hints to create the diagram below using Mathematica. (I don’t need the labels). I can do it manually, but ...

asked by Tom De Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=721 7 votes

answered by J. M.’s ennui https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 9 votes

Ignoring fractions can lead to correct answer

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238501

There is a curious example in Posamentier’s book ”Magnificent Mistakes in Mathematics” (p. 72): \((7+3/7)*(4-3/13)= 7*4=28\), where cancelling the fractions leads to correct result. If we ...

asked by Darko G https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=60625 7 votes

answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 9 votes

Context Manipulation within Scoping Constructs

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238335

In the following the full context form of Test is not required as "Aaa`" is added to ...

asked by Ronald Monson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2249 6 votes

answered by Ronald Monson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2249 2 votes

Why does NMinimize not follow MaxIterations?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238268

...

asked by Tomi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36939 6 votes

answered by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 4 votes

1.16.2 Greatest hits from previous weeks

   Is it possible to export the equations from Mathematica to MATLAB?
   How to ask Mathematica to imitate Andy Warhol’s pop-art painting?
   How to plot an ellipse?
   What’s the most difficult multidimensional integral that Mathematica has solved?
   Even Fibonacci numbers
   Find eigen energies of time-independent Schrödinger equation
   Standard deck of 52 playing cards in curated data?

Is it possible to export the equations from Mathematica to MATLAB?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=14035

Is it possible to export the output expressions from Mathematica computations (e.g., equations) in valid MATLAB syntax?

asked by Seyhmus Güngören https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4256 43 votes

answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 48 votes

How to ask Mathematica to imitate Andy Warhol’s pop-art painting?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=59132

I tried to ask Mathematica to imitate Andy Warhol, let it convert a Marilyn Monroe’s portrait so that it looks like Warhol’s world famous pop-art painting. However, the result shown below is far from ...

asked by Putterboy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=16069 52 votes

answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 67 votes

How to plot an ellipse?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=20100

I’m new to Mathematica, and I’m finding it difficult to plot an ellipse. I tried using

Plot[(x/5)^2 + (y/3)^2 == 1, {x, -5, 5}, {y, -3, 3}]

but I’m getting ...

asked by Sriram https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6075 18 votes

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 30 votes

What’s the most difficult multidimensional integral that Mathematica has solved?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222184

I am interested in benchmarking numerical integration methods and am trying to develop a wider set of difficult multivariate examples. For my particular methods, I only want to look at non-negative-...

asked by ben18785 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19278 6 votes

Even Fibonacci numbers

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=37266

Today, I found the Euler Project. Problem #2 is

Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:

asked by xyz https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9627 34 votes

answered by rcollyer https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=52 46 votes

Find eigen energies of time-independent Schrödinger equation

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=32293

I’m trying to get the eigenvalues of a one dimensional time-independent Schrödinger equation,

\(-\frac {h^2}{2m_0}\frac {d^2\psi }{dx^2}+U(x)~\psi =Ei~\psi \)

where U(x) is some potential and Ei is the ...

asked by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 49 votes

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 46 votes

Standard deck of 52 playing cards in curated data?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16108

I am not sure how to find out what all is included as curated data. For example, are the individual images of each of the 52 cards in a standard deck of playing cards included?

If not, is there a way ...

asked by JohnD https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1629 25 votes

answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 23 votes

1.16.3 Can you answer these questions?

   ListDensityPlot3D with x-axis in logscale
   Trying to solve a PDE — getting warnings I don’t understand
   How can we improve transonic flow visualization?

ListDensityPlot3D with x-axis in logscale

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238481

Starting from a data set like the one used in this post: Importing and visualizing 4D data DATA It can be viewed using ListDensityPlot3D, as follows:

asked by Ivan Y. Forero https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76882 1 vote

Trying to solve a PDE — getting warnings I don’t understand

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238231

Consider the partial differential equation

asked by beginners https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76785 2 votes

How can we improve transonic flow visualization?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238500

With this code we can make 2D FEM simulation of transonic flow around airfoil NACA 0012 at Mach number of 0.925. It takes about 5 minutes on the XENIA-15 laptop of 32 GB memory with processor Intel ...

asked by Alex Trounev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58388 4 votes

1.17 Thursday, January 14, 2021

  1.17.1 Top new questions this week
  1.17.2 Greatest hits from previous weeks
  1.17.3 Can you answer these questions?

1.17.1 Top new questions this week

   Faster ”Closest Pair of Points Problem” implementation?
   Broken ValueQ function in Mma12.2?
   Graphics not correctly produced when saving to PDF in Version 12
   MoleculePlot draws sucrose benzoate with overlapping bonds
   How to globally disable and re-enable Echo?
   Compile - Optimization of function calls - does it matter?
   neighbouring pixels : next smaller and bigger perimeter

Faster ”Closest Pair of Points Problem” implementation?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237884

The closest pair of points problem is a common computational geometry problem: given n points, find a pair of points with the smallest distance between them. A naive algorithm of finding distances ...

asked by Aaron T. Becker https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76690 17 votes

answered by Carl Woll https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45431 11 votes

Broken ValueQ function in Mma12.2?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237871

f[x] ^= 1; 
ValueQ[g[x]]

returns True in Mathematica 12.2. Is it a bug?

asked by Roma Lee https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57495 15 votes

answered by MarcoB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27951 17 votes

Graphics not correctly produced when saving to PDF in Version 12

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237994

12.0.0 for Microsoft Windows (64-bit) (April 6, 2019) How do I get my graphic to look the same in PDF as it does in a Notebook? This is what the graphic looks like in the FrontEnd:

This is how the ...

asked by Steven Thomas Hatton https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44139 10 votes

answered by MelaGo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=63360 13 votes

MoleculePlot draws sucrose benzoate with overlapping bonds

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237903

Recently I learned that in Mathematica it is possible to create chemical structures here: Chemical formulas with Mathematica I am having a problem with a structure called ”Sucrose benzoate”

asked by John https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72940 9 votes

answered by Jason B. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9490 9 votes

How to globally disable and re-enable Echo?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238163

I have Echo’s buried in code all over my notebook, I’d like a flag to turn them all on or off globally.

Sure Unprotect[Echo];Echo=Identity would disable them, but ...

asked by M.R. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=403 6 votes

answered by Carl Woll https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45431 9 votes

Compile - Optimization of function calls - does it matter?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238018

I was surprised to see that, in the results of CompilePrint for a function made with Compile, calls to ...

asked by Sean https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76328 6 votes

answered by Sean https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76328 2 votes

neighbouring pixels : next smaller and bigger perimeter

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237914

I have a list of pixels centers, for example :

asked by yfs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=71775 6 votes

answered by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 7 votes

1.17.2 Greatest hits from previous weeks

   How to make Jacobian automatically in Mathematica
   Plotting Complex Quantity Functions
   QR Code in shopping cart handle
   How do I plot a plane EM wave?
   Standard deck of 52 playing cards in curated data?
   Why I get the ”Set::write: ”Tag Times in is Protected.” error?
   Mathematica vs. Python - how does Mathematica compare to Python’s scientific computing suite?

How to make Jacobian automatically in Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=5790

If we have two vectors, \(a\) and \(b\), how can I make Jacobian matrix automatically in Mathematica?

$$ a=\left( 
\begin{array}{c} 
 x_1^3+2x_2^2 \\ 
 3x_1^4+7x_2 
\end{array} 
\right);b=\left( 
\begin{array}{...

asked by George Mills https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1012 39 votes

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 52 votes

Plotting Complex Quantity Functions

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3458

Trying to plot with complex quantities seems not to work properly in what I want to accomplish. I would like to know if there is a general rule/way of plotting when you have complex counterparts in ...

asked by night owl https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=116 42 votes

answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 29 votes

QR Code in shopping cart handle

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=26268

This week, the market people from my work wanted to put QR codes in shopping cart handles, but when they tested it, the QR code did not work. I noted that the cylindrical curvature (even small) ...

asked by Murta https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2266 196 votes

answered by halirutan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=187 192 votes

How do I plot a plane EM wave?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=1987

I would like to display an electromagnetic (EM) wave. I have written code that works, but it does not ”shade” the area between the graph and the axes. Both the ...

asked by Rainforest Frog https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=202 22 votes

answered by J. M.’s ennui https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 16 votes

Standard deck of 52 playing cards in curated data?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16108

I am not sure how to find out what all is included as curated data. For example, are the individual images of each of the 52 cards in a standard deck of playing cards included?

If not, is there a way ...

asked by JohnD https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1629 25 votes

answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 23 votes

Why I get the ”Set::write: ”Tag Times in is Protected.” error?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11868

Why I get the error below with this code:

asked by Aurelius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1669 10 votes

answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 13 votes

Mathematica vs. Python - how does Mathematica compare to Python’s scientific computing suite?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=86058

Python’s family of packages for scientific computing has matured rapidly. I can pretty much replicate all of Mathematica’s functionalities, but with production level and open-source code using the ...

asked by M.R. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=403 49 votes

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 36 votes

1.17.3 Can you answer these questions?

   NDSolve - interpolation or machine precision problem
   Matrix regularization, how to pick \(\lambda \)
   Memory consuming Expand

NDSolve - interpolation or machine precision problem

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237920

For the following equations;

asked by confused https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74890 1 vote

Matrix regularization, how to pick \(\lambda \)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237834

Since v12 FindFit[] now supports regularisation, such as Tikhonov regularization. Do there exist statistics to help guide the choice of the hyper-parameter

asked by Tomi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36939 2 votes

Memory consuming Expand

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238106

Expand floods all my 64GB RAM in MMA 12.1 (Windows). Therefore I cannot run the code. Somebody with ¿64GB RAM could give the result. A memory saving alternative ...

asked by granular bastard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69288 1 vote

1.18 Thursday, January 7, 2021

  1.18.1 Top new questions this week
  1.18.2 Greatest hits from previous weeks:
  1.18.3 Can you answer these questions?

1.18.1 Top new questions this week

   Why MMA refuses to simplify the following simple expression?
   Simplifying code that displays a square rolling inside a circle
   Trying to build a code to translate handwritten formulas using ML
   How to define a function reminding of names of the independent variables?
   Improve running speed for DeleteDuplicates
   Why does Mathematica try to take the first element of the empty list when plotting?
   Why do the frame ticks disapear when a plot is exported as PNG?

Why MMA refuses to simplify the following simple expression?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237547

I have the following simple expression Exp[(Log[1 + x]^2 - Log[x]^2)/Log[1 + 1/x]] - x^2

that can be shown to simplify to \(x\)

asked by user16320 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=16320 13 votes

answered by yarchik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9469 5 votes

Simplifying code that displays a square rolling inside a circle

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237692

The vertex A,B of the square ABCD with side length \(\sqrt {2}\) is on the circle with radius \(\sqrt {2}\), vertex C,D is inside the circle, roll the square ABCD along the inside of the circle ...

asked by expression https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7339 10 votes

answered by David G. Stork https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9735 0 votes

Trying to build a code to translate handwritten formulas using ML

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237533

I’m lazy writing equations in Latex so I want a code to translate handwritten equations. This question is related to an old experiment I’m reviewing during vacations, here. I’m trying to use ...

asked by Gluoncito https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8696 10 votes

How to define a function reminding of names of the independent variables?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237458

I am using a function with a lot of variables. There are 9 and sometimes more of them. In this case, it is difficult to memorize, which one stays on the, say, fourth position, and which one - on the ...

asked by Alexei Boulbitch https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=788 8 votes

answered by CA Trevillian https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=63039 2 votes

Improve running speed for DeleteDuplicates

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237681

How to make this faster? I want to remove elements that satisfy the condition below but it’s way too slow.

asked by anhnha https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18805 8 votes

answered by WReach https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=142 10 votes

Why does Mathematica try to take the first element of the empty list when plotting?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237785

I’m using Mathematica 12.1.1.0. When I enter

asked by Jason Gross https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12258 7 votes

answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 3 votes

Why do the frame ticks disapear when a plot is exported as PNG?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237678

I am using M12.0.0.0 on Ubuntu and I have these two plots:

asked by valar morghulis https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26937 6 votes

answered by Rolf Mertig https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29 5 votes

1.18.2 Greatest hits from previous weeks:

   What do the X and Y axis stand for in the Fourier transform domain?
   How can I plot the direction field for a differential equation?
   Is Mathematica worth it for me?
   How to ask Mathematica to imitate Andy Warhol’s pop-art painting?
   Figuring when the minute and hour hand coincide on a clock
   Conversion of Sine to Cosine
   Finding unit tangent, normal, and binormal vectors for a given r(t)

What do the X and Y axis stand for in the Fourier transform domain?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=85139

In Wolfram Mathematica the function Fourierhas the following declaration

Fourier[list]

And after a list is given to the ...

asked by user253956 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29958 27 votes

answered by Hugh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12558 61 votes

How can I plot the direction field for a differential equation?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8841

I’d like to plot the graph of the direction field for a differential equation, to get a feel for it. I’m a novice, right now, when it comes to plotting in Mathematica, so I’m hoping that someone can ...

asked by Matt Groff https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1735 31 votes

answered by Peter Breitfeld https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=307 25 votes

Is Mathematica worth it for me?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=100072

I’m 13 years old and in 7th grade. I’m currently in Algebra 1, and I have fallen in love with both math and programming.

When I came upon Mathematica, it was awesome. My two favorite things fused ...

asked by Nico A https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=35769 81 votes

answered by Pillsy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=531 55 votes

How to ask Mathematica to imitate Andy Warhol’s pop-art painting?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=59132

I tried to ask Mathematica to imitate Andy Warhol, let it convert a Marilyn Monroe’s portrait so that it looks like Warhol’s world famous pop-art painting. However, the result shown below is far from ...

asked by Putterboy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=16069 52 votes

answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 67 votes

Figuring when the minute and hour hand coincide on a clock

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=573

I would like to list all possible times in a 12-hour period, where the hour hand overlaps the minute hand completely. This is really a question about three distinct things - to be done in Mathematica ...

asked by Steve D https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=191 15 votes

answered by Verbeia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8 21 votes

Conversion of Sine to Cosine

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=67521

I’m solving equations with many Cosines and Sines. And I want to convert all the Sines to Cosines using trigonometric formulas such as cos(x)=sin(x+pi/2). How can I do this?

asked by YongCheol Kwon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23041 4 votes

answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 2 votes

Finding unit tangent, normal, and binormal vectors for a given r(t)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18598

For my Calc III class, I need to find \(T(t), N(t)\), and \(B(t)\) for \(t=1, 2\), and \(-1\), given \(r(t)=\{t,t^2,t^3\}\).

I’ve got Mathematica, but I’ve never used it before and I’m not sure how to coerce ...

asked by a98 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5605 30 votes

answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 44 votes

1.18.3 Can you answer these questions?

   Numerically obtaining inverse 2D Laplace transform
   How to determine population from a list of arbitrary jurisdictions (cities, states, counties, et al.)?
   Computing correspondences between two images

Numerically obtaining inverse 2D Laplace transform

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237480

I wonder if there is a function in Mathematica (or code) that can help obtaining inverse 2D Laplace transform of a function, f(s1,s2) which is the 2D Laplace transform of a function F(t1,t2) in (s1,s2)...

asked by Refaat Galal https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76583 1 vote

How to determine population from a list of arbitrary jurisdictions (cities, states, counties, et al.)?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237541

I am an aspiring data scientist who’s working on a passion project, namely to assign danger-level scores to police departments in the United States. One specific metric I’m developing results from ...

asked by uselesslemma https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72297 3 votes

answered by George Varnavides https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=41179 0 votes

Computing correspondences between two images

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237484

A classic problem in computer vision is computing correspondences between keypoints in two similar images, despite modest variations in size, lightness, orientation, etc., of the images, as ...

asked by David G. Stork https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9735 6 votes

Chapter 2
Year 2020

 2.1 Thursday, December 24, 2020
 2.2 Thursday, December 17, 2020
 2.3 Thursday, December 10, 2020
 2.4 Thursday, December 3, 2020
 2.5 Thursday, November 19, 2020
 2.6 Thursday, November 12, 2020
 2.7 Thursday, November 5, 2020
 2.8 Thursday, October 29, 2020
 2.9 Thursday, October 22, 2020
 2.10 Thursday, October 15, 2020
 2.11 Thursday, October 1, 2020
 2.12 Thursday, September 24, 2020
 2.13 Thursday, September 17, 2020
 2.14 Thursday, September 10, 2020
 2.15 Thursday, September 3, 2020
 2.16 Thursday, August 20, 2020
 2.17 Thursday, August 13, 2020
 2.18 Thursday, August 6, 2020
 2.19 Thursday, July 23, 2020
 2.20 Thursday, July 16, 2020
 2.21 Thursday, July 9, 2020
 2.22 Thursday, July 2, 2020
 2.23 Thursday, June 25, 2020
 2.24 Thursday, June 18, 2020
 2.25 Thursday, June 4, 2020
 2.26 Thursday, May 28, 2020
 2.27 Thursday, May 21, 2020
 2.28 Thursday, May 14, 2020
 2.29 Thursday, May 7, 2020
 2.30 Thursday, April 23, 2020
 2.31 Thursday, April 16, 2020
 2.32 Thursday, April 9, 2020
 2.33 Thursday, April 2, 2020

2.1 Thursday, December 24, 2020

  2.1.1 Top new questions this week
  2.1.2 Greatest hits from previous weeks
  2.1.3 Can you answer these questions?

2.1.1 Top new questions this week

   These PDE’s no longer evaluate in version 12.2 as they did under 12.1. What can be done to make them evaluate under 12.2?
   Travelling around Jupiter
   Numerically evaluating parameter derivatives of a hypergeometric function
   Numeric Solution Hydrogen Atom
   Sum cause a Recursion problem
   Is it possible to ask Mathematica to give the maximum value of a function over a specific domain?
   Unrolling a surface

These PDE’s no longer evaluate in version 12.2 as they did under 12.1. What can be done to make them evaluate under 12.2?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236895

These 399 PDE’s no longer produce result under Version 12.2 on windows. DSolve now returns unevaluated. These all evaluated under version 12.1. Why is that? And ...

asked by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 17 votes

answered by Devendra Kapadia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18617 12 votes

Travelling around Jupiter

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236843

Since we have soon historical conjunction of Jupiter and Saturn I have prepared code with visualization planet Jupiter and Saturn with moons. This code first been prepared for version 11.3 and with ...

asked by Alex Trounev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58388 16 votes

Numerically evaluating parameter derivatives of a hypergeometric function

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237032

I am unable to obtain the numerical value of the derivative of the hypergeometric function. Please note that the (2,4,0,0) is the derivative with respect to the first and second argument

asked by Sachin Kaushik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58727 7 votes

answered by Mariusz Iwaniuk https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26828 7 votes

Numeric Solution Hydrogen Atom

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236980

I’m trying to solve the Schrödinger equation for the hydrogen atom without made the variable separation of the polar and radial coordinate. It is my test code to extrapolate to another system with its ...

asked by Jorge Castaño https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73029 7 votes

answered by Jorge Castaño https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73029 0 votes

Sum cause a Recursion problem

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236934

Sum[((-1)^(i + 1)*Binomial[n, i]*(n - i)!)/n!, {i, 1, n}]

This cause a Recursion problem.

As the comment said, If simplify the formula and then sum it, problem ...

asked by wuyudi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68689 6 votes

Is it possible to ask Mathematica to give the maximum value of a function over a specific domain?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236971

I have a function \(f(n)\) over \(n\in \mathbb {N}\). I want to know its maximum value over a very large domain, say \(n=1,2,3,4,...,10^6\). Is there a way to ask Mathematica to give me the maximum value of ...

asked by charmin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74550 6 votes

answered by MarcoB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27951 9 votes

Unrolling a surface

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237045

The surface is determined by this parametric equation ParametricPlot3D[{Cos[θ],Sin[θ],z(2+ Cos[θ])},{θ,-Pi,Pi},{z,0,1}]

How to unfold the surface in Mathematica? ...

asked by expression https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7339 5 votes

answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 3 votes

2.1.2 Greatest hits from previous weeks

   Conversion of Sine to Cosine
   How to ask Mathematica to imitate Andy Warhol’s pop-art painting?
   Plot, extract data to a file
   My Girlfriend is going to prison...Save her with Math
   How to create animated snowfall?
   Parallel and perpendicular symbol from Mathematica to LaTeX
   1 Plot, 2 Scale/Axis

Conversion of Sine to Cosine

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=67521

I’m solving equations with many Cosines and Sines. And I want to convert all the Sines to Cosines using trigonometric formulas such as cos(x)=sin(x+pi/2). How can I do this?

asked by YongCheol Kwon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23041 3 votes

answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 1 vote

How to ask Mathematica to imitate Andy Warhol’s pop-art painting?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=59132

I tried to ask Mathematica to imitate Andy Warhol, let it convert a Marilyn Monroe’s portrait so that it looks like Warhol’s world famous pop-art painting. However, the result shown below is far from ...

asked by Putterboy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=16069 51 votes

answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 66 votes

Plot, extract data to a file

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19859

I need to save data that Mathematica uses inside the Plot command. The format that I would like to have is:

x1 y1 
x2 y2 
.....

asked by molkee https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5097 30 votes

answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 46 votes

My Girlfriend is going to prison...Save her with Math

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=135937

Salacious title, but true story.

asked by Prisoners Dilema https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46025 42 votes

answered by bobthechemist https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7167 23 votes

How to create animated snowfall?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16881

Well, the title is self-explanatory. What sorts of snowfall can we generate using Mathematica? There are two options I suggest to consider:

1) Continuous GIF animations with smallest possible number ...

asked by faleichik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=219 40 votes answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 54 votes

Parallel and perpendicular symbol from Mathematica to LaTeX

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=46538

I want to get the following expression from Mathematica to LaTeX:

\[ \begin {bmatrix} E_{\parallel } \\ E_{\perp } \end {bmatrix} \]

I have tried to use inbuilt 'symbol' character from the special ...

asked by Steve Hatcher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13314 19 votes

answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 27 votes

1 Plot, 2 Scale/Axis

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=627

I would like to plot those two datasets on top of each other. But they have very different range on the \(y\) axis. How can I have two different axis?

I found the following on the help menu but quite ...

asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 148 votes

answered by ArgentoSapiens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=92 151 votes

2.1.3 Can you answer these questions?

   How to determine if a number is an integer power?
   dot product of vectors with noncommutative elements
   How to Inherit Arrowheds size?

How to determine if a number is an integer power?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236779

How can I do simple tests like determining if an integer is a power of 2? Mathematically, the result below should be True, and I understand why it doesn’t work on MMa, but how do I do this test ...

asked by Jerry Guern https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=20042 1 vote

dot product of vectors with noncommutative elements

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237042

I came upon an interesting problem. Suppose you have three vectors \(\psi =(a, b)\), \(\phi =(c,d)\) such that their components do not commute: \(ac\neq ca\), \(bd \neq db\) etc. (in general the vectors may ...

asked by geom https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68502 1 vote

How to Inherit Arrowheds size?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236932

I’m trying to write a Module that produces some arrows with custom Arrowhead shapes. However, I want the code external to the

asked by Wynne https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36616 1 vote

2.2 Thursday, December 17, 2020

  2.2.1 Top new questions this week
  2.2.2 Greatest hits from previous weeks
  2.2.3 Can you answer these questions?

2.2.1 Top new questions this week

   Plotting the Star of Bethlehem
   Opacity gradient in custom legend
   Circle Packing in Cone Texture
   Is there a Mathematica CUDA ode solver?
   How to properly use the function ThermodynamicData
   How do I reorder and combine sublists based on sublist rankings given by another list?
   How to convert cuboid to mesh efficiently

Plotting the Star of Bethlehem

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236499

Christmas is around the corner! In preparation, consider the polynomial f[x_,y_]:= 1/10 (4 - x^2 - 2 y^2)^2 + 1/2 (x^2 + y^2) 

and define \(r=(f_x,f_y)\) using the ...

asked by fwgb https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44151 19 votes

answered by xzczd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1871 15 votes

Opacity gradient in custom legend

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236442

I need to produce the legend of a plot which encodes a color gradient together with a color gradient. In particular, I would like the image bellow to have the blueish edge faded and the redish solid:

asked by Marcelo Broinizi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53497 6 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes

Circle Packing in Cone Texture

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236449

This is a cone with texture generated by PatternFilling in plane. The problem this texture mapping is not conformal. So my question is how to generated a pattern image which could suit a fixed height ...

asked by HyperGroups https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6648 5 votes

answered by cvgmt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72111 3 votes

Is there a Mathematica CUDA ode solver?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236625

I have a system of ODEs which I’d like to solve with many (thousands) different initial conditions. In the net there are articles that CUDA can speed up such computations, but I haven’t found ...

asked by Andrew https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=306 5 votes

How to properly use the function ThermodynamicData

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236558

I’ve been trying to use the function ThermodynamicData, and it is going fine when I try to calculate properties such as Enthalpy or Entropy or even phase as a ...

asked by Igor Stravinsky https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=35043 5 votes

answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 2 votes

How do I reorder and combine sublists based on sublist rankings given by another list?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236526

I have two lists:

asked by Gregorio https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75996 5 votes

answered by wuyudi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68689 2 votes

How to convert cuboid to mesh efficiently

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236306

cuboids = 
Table[Cuboid @@ (pts = RandomReal[100, {2, 3}]), {i, 10000}]; 
 
Method1:

asked by HyperGroups https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6648 5 votes

answered by chyanog https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2090 6 votes

2.2.2 Greatest hits from previous weeks

   Mathematica code for Bifurcation Diagram
   What are the most common pitfalls awaiting new users?
   Calculate the 2D Fourier transform of an Image
   How to make the digits of π go around in a spiral like this?
   How to make a Spherical Cow?
   How can I plot a graph of an integral?
   How to tell Mathematica that certain variables are real/imaginary, integer-valued, etc

Mathematica code for Bifurcation Diagram

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=13277

At the moment I am trying to construct a bifurcation diagram of the iterative function \(f(x)=\) \(ax-1.1975x^3\). I’ve scoured the internet for pre-made bifurcation diagrams and found many (mostly of the ...

asked by Mel https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=3249 27 votes

answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 47 votes

What are the most common pitfalls awaiting new users?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18393

As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...

asked by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 473 votes answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 285 votes

Calculate the 2D Fourier transform of an Image

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=29203

I am new to Mathematica, and using version 8.0.

I would like to calculate the 2D Fourier Transform of an Image with Mathematica and plot the magnitude and phase ...

asked by user8727 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8727 17 votes

answered by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 33 votes

How to make the digits of π go around in a spiral like this?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=109982

Here is a start.

MapIndexed[Text[Reverse[First[RealDigits[Pi,10,252]]][[Tr@#2]],#]&, 
 Table[{t Cos[t],t Sin[t]},{t,0,16Pi,0.2}]]//Graphics

asked by matrix89 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5379 57 votes

answered by Martin Ender https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2305 73 votes

How to make a Spherical Cow?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=125043

Being a theoretical physicist, I always have a great respect for Spherical Cow. So I thought about making one myself. I am not sure how can I create (something considered to be the simplest!) this ...

asked by Sumit https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8070 69 votes

answered by andre314 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5467 76 votes

How can I plot a graph of an integral?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=78451

I want to plot the following function:

∫       Γ (x + 1)  Γ (x − 1)
  ∖left(--------−  --------∖right) dx
           2          2

asked by Anixx https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=651 4 votes

answered by k_v https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=24727 9 votes

How to tell Mathematica that certain variables are real/imaginary, integer-valued, etc

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=66273 I’m trying to expedite some quantum mechanical calculations (expectation values etc.) by running them through Mathematica. When I say, for example,

asked by Matthew Brunetti https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=22304 39 votes

answered by SquareOne https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19960 24 votes

2.2.3 Can you answer these questions?

   Interpolation for different Parameters
   Problem in iterative equation
   Importing equations generated in subpackage to be solved in another subpackage

Interpolation for different Parameters

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236606

I am rather new to Mathematica and I tried to find a solution for my Problem on my own, also looking through this site and the suggested Similar Questions, but I at least could not make out that my ...

asked by n00bBoi1 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76302 1 vote

Problem in iterative equation

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236532

I am solving the following iterative equation to calculate Tf and Cp as a function of temperature:

An initial attempt for a ...

asked by John https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72940 2 votes

Importing equations generated in subpackage to be solved in another subpackage

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236345

I have a package which contains two subpackages: one ("`MOTSimulator`MOTGenerator") which generates a systems of differential equations of the form

asked by crich https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76216 1 vote

2.3 Thursday, December 10, 2020

  2.3.1 Top new questions this week
  2.3.2 Greatest hits from previous weeks

2.3.1 Top new questions this week

   Find the equidistance curve between two curves
   Confused by results of FunctionDomain
   Cannot reproduce well-known summation result
   Is there a way to get tooltip for parts of a string?
   Nice use case for symbolic tensors?
   Drawing hollow disks in 3D with an sphere in center and small spheres on the rings
   Solve‘DirInf[] — Meaningful value or just a bug?

Find the equidistance curve between two curves

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235971

I have three function \(f(x)=x^x\), \(g(x)=\ln (x)^{\ln (x)}\), \(h(x)=\ln (x)^2\) and I want to find (numerically) \(C\) the center of the circle tangent to the three curves.

I think that one way is to find ...

asked by Domenico Modica https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76121 14 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 14 votes

Confused by results of FunctionDomain

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236138

Why does Mathematica give me the function domain of

               1          1         1
f (x ) = (2x − 3)5 − (2x + 1)5 − (x− 3)5

as \(x\geq 3\)? I used this command:

asked by Ramez Hindi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76160 7 votes

answered by Roderic https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76085 8 votes

Cannot reproduce well-known summation result

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236149

Bug introduced in 4.2 or 5.0, persisting through 12.2.0.

Note: this is a repost of my OP on math.SE. I am posting it here because multiple users with different Mathematica versions have given me the ...

asked by Klangen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=49819 7 votes

answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 3 votes

Is there a way to get tooltip for parts of a string?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235911

Is there a way to get the tooltip to appear for parts of a string?

asked by user13892 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13892 7 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 9 votes

Nice use case for symbolic tensors?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236188

I come from before the times of symbolic tensors in Mathematica, and am used to working with concrete tensors and custom commands to contract them using Transpose, Dot, etc. I recently realized that ...

asked by Stijn https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69486 6 votes

answered by jose https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10552 2 votes

Drawing hollow disks in 3D with an sphere in center and small spheres on the rings

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236161

I was trying to draw the following logo of an atom using Mathematica, but I could only figure out how to draw intersecting ellipses, not a nice logo like below. Do you have any idea? And is ...

asked by Saeid https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=35814 6 votes

answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 7 votes

Solve‘DirInf[] — Meaningful value or just a bug?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236077

Bug introduced in 4.1 or earlier and persisting through 12.2.0. or later

To the problem below, I get four independent, incomplete solutions, three in terms of ...

asked by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 6 votes

answered by Akku14 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34287 0 votes

2.3.2 Greatest hits from previous weeks

   Why is raytracing so slow?
   Generate a Unit Circle Trigonometry
   Drawing a square root spiral
   How do I make a 3DPlot using cylindrical coordinates?
   How to calculate contour integrals with Mathematica?
   Skip header lines on import
   Using Export[] sends the file where?
   Can you answer these questions
   Periodical sum of rows by a certain step
   Behavior of $MinPrecision seems to have changed between 12.0.0 and 12.1.1
   HankelTransform problem

Why is raytracing so slow?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219629

I’m trying to get some rays to bounce in a circle. But I want to be able to control the reflections, i.e. the direction the rays bounce in the circle. I have a MWE below, and it is severely limited by ...

asked by Tomi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36939 31 votes

answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 42 votes

Generate a Unit Circle Trigonometry

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2456

Struggling often with Trigonometry I would like to have some code to generate this Unit Circle Trigonometry. Would be of great help when I need to transform some data :

asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 18 votes

answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 32 votes

Drawing a square root spiral

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=66969

Here is a start. I’m looking for a nice way to draw it.

asked by matrix89 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5379 24 votes

answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 21 votes

How do I make a 3DPlot using cylindrical coordinates?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19076

I’m trying to plot a function of the form \(z(r,\theta )\) where \(r \in [0, R]\) for a finite R, \(\theta \in [0,2\pi [\), and z is the third coordinate, a function of the first two. I couldn’t find anything ...

asked by Learning is a mess https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5643 18 votes

answered by whuber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=91 24 votes

How to calculate contour integrals with Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=34073

How to calculate the integral of \(\frac {1}{\sqrt {4 z^2 + 4 z + 3}}\) over the unit circle counterclockwise for each branch of the integrand?

asked by user64494 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7152 42 votes

answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 64 votes

Skip header lines on import

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=50718

When importing a data file what are the comment symbols for Mathematica? That is, given a file like this

blabla 
bulbul 
 
1 2 6 54 7 ...

what symbol do I have ...

asked by MaxJ https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=14687 20 votes

answered by george2079 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2079 18 votes

Using Export[] sends the file where?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8586

I am trying to use the Export command to convert a list of plots into a *.gif file, and the command runs and executes well, but I can’t find the file! Where is it ...

asked by Patrick Da Silva https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1785 37 votes

answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 51 votes

Can you answer these questions

Periodical sum of rows by a certain step

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236085

I’ve been struggling with one problem. I have a classic matrix in this example 12x4 such as: matrix = Table[i, {i, 12}, {4}]

asked by Jakub Petrůj https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75456 2 votes

answered by Carl Woll https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45431 0 votes

Behavior of $MinPrecision seems to have changed between 12.0.0 and 12.1.1

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235851

I am running into a very weird bug where setting $MinPrecisionto some value (in this case 200 has a very different and ...

asked by Kvothe https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45020 3 votes

HankelTransform problem

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236119

Somewhere in the following code there is a bug. The result should not be zero! FunctionExpand@HankelTransform[Sqrt[r] Cos[r], r, k, 1/2]

I think the answer should ...

asked by SolutionExists https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70331 1 vote

2.4 Thursday, December 3, 2020

  2.4.1 Top new questions this week
  2.4.2 Greatest hits from previous weeks
  2.4.3 Can you answer these questions?

2.4.1 Top new questions this week

   Interpolation on an unstructured mesh
   Tower of Pisa function
   How can I ingest and analyze benchmark results posted at MSE?
   Construct a polyhedron from the coordinates of its vertices and calculate the area of each face
   Make an InterpolatingFunction periodic
   How do I place the Clock arrows inside this clock face?
   How can I sketch a right-angled triangle?

Interpolation on an unstructured mesh

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235681

This may have a duplicate but I have spent some time looking and can’t find it. I have experimental data in the form of { {x1, y1, z1}, {x2, y2, z2}...} I wish to interpolate it so my thoughts turned ...

asked by Hugh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12558 10 votes

answered by user21 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18437 8 votes

Tower of Pisa function

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235495

I’m trying to construct a ’smooth’ function \(f : \mathbb {R}^2 \longrightarrow [0,1]\) such that all level sets

{x|f(x) = y}

are circles in a way that \(f\) looks like the ’Leaning Tower of Pisa’.

asked by darksun https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75863 10 votes

answered by fwgb https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44151 7 votes

How can I ingest and analyze benchmark results posted at MSE?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235390

How can I ingest Mathematica / WL benchmark results posted at Mathematica Stack Exchange (MSE), like the ones posted here? Assumptions:

There are multiple answers with benchmarks posted

asked by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 10 votes

answered by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 12 votes

Construct a polyhedron from the coordinates of its vertices and calculate the area of each face

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235524

I have the 3D coordinates for a set of points. I want to construct the convex polyhedron with those points as vertices.

I know I can use functions like DelaunayMesh

asked by Dennis https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69969 9 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes

Make an InterpolatingFunction periodic

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235403

Interpolation can make an InterpolatingFunction periodic with the option ...

asked by Chris K https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6358 8 votes

answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 3 votes

How do I place the Clock arrows inside this clock face?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235711

I am trying to program a clock, I have the face I want and the hands but I can not seem to put them together so they work.....

asked by Struggling Student https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75041 7 votes

answered by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 6 votes

How can I sketch a right-angled triangle?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235413

I would like to replicate this ellipse, but with a right-angled triangle (with smooth/rounded corners). The formula for this ellipse:

asked by nightcape https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75304 7 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes

2.4.2 Greatest hits from previous weeks

   Elegant operations on matrix rows and columns
   Positioning axes labels
   How to create word clouds?
   How do I clear all user defined symbols?
   What does # mean in Mathematica?
   How to manipulate 2D plots?
   How to make an inkblot?

Elegant operations on matrix rows and columns

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3069

Question

The Mathematica tutorial has a section ’Basic Matrix Operations’, describing operations like transpose, inverse and determinant. These operations all work on entire matrices. I am missing a ...

asked by sjdh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=515 180 votes

answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 61 votes

Positioning axes labels

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=87388

I need to change the position of my axes labels such that the y-axis label is in the middle and parallel to the y-axis. I’d also like the x-axis label to be in the middle of the x-axis rather than ...

asked by John_dydx https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7849 15 votes

answered by Virgil https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27697 16 votes

How to create word clouds?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2334

Word clouds are rather useless fancy and visually appealing plots, where words are plotted with different sizes according to their frequency in a corpus. Many applications exist out there (Wordle, ...

asked by István Zachar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 145 votes

answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 119 votes

How do I clear all user defined symbols?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=850

Is there some way to do this other than going to Evaluation -> Quit kernel and firing a new one up?

asked by niklasfi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=82 97 votes

answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 95 votes

What does # mean in Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19035

I asked Mathematica to compute the following

Solve[c (1-x)^2-x^(1/4) == 0, x]

and it returned this:

  x = Root[#1^8 c^4 - 8 #1^7 c^4 + 28 #1^6 c^4 - 56 #1^5 c^4 

asked by ronanymous https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5730 38 votes

answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 64 votes

How to manipulate 2D plots?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=7142

When it comes to visual analysis, large datasets or data with intricate internal details often makes plotting in 2D useless, as the outcome is either just a fraction of the full dataset, or no details ...

asked by István Zachar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 134 votes

answered by István Zachar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 154 votes

How to make an inkblot?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3345

How to effectively create a polygon that looks like a realistic inkblot? So far, I could come up with this (borrowing from Ed Pegg Jr.’s Rorschach demonstration):

asked by István Zachar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 86 votes

answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 51 votes

2.4.3 Can you answer these questions?

   What is the fastest way to get the lowest eigenvalue and corresponding eigenstate in Mathematica?
   How do I get built-in functions to use custom objects as if they were e.g. List?
   How to speed up this code (finding eigenvector with smallest eigenvalue)?

What is the fastest way to get the lowest eigenvalue and corresponding eigenstate in Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235678

I tried to use the Arnoldi method to get the smallest eigenvalue and corresponding eigenstate for large matrix. However, Arnoldi did not give me the desired result:

asked by lol https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=40838 2 votes

How do I get built-in functions to use custom objects as if they were e.g. List?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235391

(This is part 2 of my earlier question, Can I overload Part for specific heads (a la overloaded array subscripting)?, which was well-answered as asked.)

Overview: My goal is to create a custom object -...

asked by Josh Helzer https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75893 3 votes

How to speed up this code (finding eigenvector with smallest eigenvalue)?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235775

I have following code. The function TraceSystem is to take partial trace of matrix and I think this part is fine. The main code is below in dd and I think the main problem is in here for Eigenvector. ...

asked by lol https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=40838 1 vote

2.5 Thursday, November 19, 2020

  2.5.1 Top new questions this week
  2.5.2 Greatest hits from previous weeks
  2.5.3 -Can you answer these questions?

2.5.1 Top new questions this week

   3D Inclusion with structured mesh and coarse and arbitrary matrix
   Smoother jelly / water effect on an image
   Can Mathematica be used to edit MP3 tags?
   How can I put the edge of a rectangle inside it rather than outside it?
   How do I invert my matrix?
   How to convert a Dataset into an indexed dataset / association-of-associations given a column header?
   Automatically draw chords from n-1 points on a circle to a fixed point on the circle

3D Inclusion with structured mesh and coarse and arbitrary matrix

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234780

I am wondering if there is a simple way to define a structured 3D mesh (inclusion) like e.g. that and surround it with a corse and unstructured Matrix. It should be possible to refine both more or ...

asked by Max https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68812 15 votes

answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 8 votes

Smoother jelly / water effect on an image

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234653

I’m trying to achieve a jelly / water surface effect. I’d like it to be a bit smoother. Here I am taking a triangulated rectangle and perturbing all points by a little random noise for each frame. ...

asked by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 14 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 15 votes

Can Mathematica be used to edit MP3 tags?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234564

Can Mathematica edit mp3 tags? I have a set of files and I’d like to batch process artist, album title, etc. I know other tools exist; I wonder if Mathematica can do it.

asked by GregH https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4393 11 votes

answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 15 votes

How can I put the edge of a rectangle inside it rather than outside it?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234866

Problem: when I draw a rectangle and put a coloured edge around it, the displayed edge is centred along the nominal edge and if it follows the same course as one of the axes then it does not show up. ...

asked by ruffle https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=59886 7 votes

answered by Brett Champion https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69 5 votes

How do I invert my matrix?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234836

I have the following matrix \(M\):

\begin{bmatrix} 
P & p & 0 & 0 \\ 
pe_1 & Pe_1 & \sqrt{P^2 - p^2}q_1 & \sqrt{P^2 - p^2}r_1 \\ 
pe_2 & Pe_2 & \sqrt{P^2 - p^2}q_2 & 
\end{bmatrix}

asked by Ansonī Bōdo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75764 7 votes

answered by LouisB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=22158 14 votes

How to convert a Dataset into an indexed dataset / association-of-associations given a column header?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234931

Given a dataset as such

If ”letter” is the header that is chosen, how do I convert it into an indexed dataset / association-of-associations? i.e. How do ...

asked by IntroductionToProbability https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=60568 6 votes

answered by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 6 votes

Automatically draw chords from n-1 points on a circle to a fixed point on the circle

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234729

I want to put n equally spaced points on a circle and automatically draw chords from all points to a fixed point preferably P(0,0). I have managed to draw the points and the circle so far with

asked by Guy Foxx https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75736 6 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 5 votes

2.5.2 Greatest hits from previous weeks

   How to find the position of elements in a list satisfying criteria
   Finding Limits in several variables
   Why round to even integers?
   Why is raytracing so slow?
   How do I identify the source of a ”Tag times protected” error?
   Mathematica command that allows it to read my intentions
   How to make a Spherical Cow?

How to find the position of elements in a list satisfying criteria

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=180

Say I have a list x={2,4,6,8,10} and I want to find out the positions of the elements that are greater than 7.

asked by PeterR https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=140 67 votes

answered by J. M.’s discontentment https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 63 votes

Finding Limits in several variables

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=21544

Is there a way to find a limit of a multivariable function, like

(x,yl)im→ (0,0)f(x,y)

with Mathematica?

When \(f\) is continuous, we can use

   lim    f(x,y) = lim
(x,y)→(0,0)         (x,0)

asked by Dominic Michaelis https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5899 31 votes

answered by whuber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=91 42 votes

Why round to even integers?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2116

According to the Mathematica help:

Round rounds numbers of the form x.5 toward the nearest even integer.

For example:

Round[{0.5, 1.5, 2.5, 3.5, 4.5}]

gives

asked by wxffles https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=427 82 votes

answered by Per Alexandersson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=488 50 votes

Why is raytracing so slow?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219629

I’m trying to get some rays to bounce in a circle. But I want to be able to control the reflections, i.e. the direction the rays bounce in the circle. I have a MWE below, and it is severely limited by ...

asked by Tomi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36939 31 votes

answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 42 votes

How do I identify the source of a ”Tag times protected” error?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11982

I have some code that looks like

Table[ 
    a = 1; 
    b = {2, 3} 
    c = i;, 
    {i, 2} 
]

which gives an error:   Set::write: Tag Times in c {2,3} is Protected....

asked by dearN https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=204 29 votes

answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 35 votes

Mathematica command that allows it to read my intentions

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=194384

In version 2.0 of Mathematica there was a command, ReadProgrammerIntentions[ ] which allowed it rapidly compose code that could solve problems simple to complex, ...

asked by MikeY https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=47314 52 votes

answered by MarcoB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27951 38 votes

How to make a Spherical Cow?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=125043

Being a theoretical physicist, I always have a great respect for Spherical Cow. So I thought about making one myself. I am not sure how can I create (something considered to be the simplest!) this ...

asked by Sumit https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8070 69 votes

answered by andre314 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5467 76 votes

2.5.3 -Can you answer these questions?

   Setting pieces of ”matrices” - unwanted behavior
   system of coupled nonlinear pdes with FEM (magneto-hydrodynamic mass transfer)
   Create a Cellular Automata rule in Mathematica

Setting pieces of ”matrices” - unwanted behavior

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234703

I am constructing matrices whose elements are lists themselves (of varying length), and am (re)setting the entries of these matrices using among others the ”All” command. It seems that in ...

asked by Stijn https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69486 2 votes

system of coupled nonlinear pdes with FEM (magneto-hydrodynamic mass transfer)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234749

I’m trying to reproduce the magneto-hydrodynamic flow studied here using the nonlinear FEM functionality, and have been having trouble implementing the Neumann boundary conditions. Pardon the long ...

asked by George Varnavides https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=41179 1 vote

Create a Cellular Automata rule in Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234577

I want to create an image in a cellular automata, more specifically an image of an object, like a turtle for example. I found this article online, and i am trying to replicate the results for growing ...

asked by Joana Bugalho https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75694 2 votes

2.6 Thursday, November 12, 2020

  2.6.1 Top new questions this week
  2.6.2 Greatest hits from previous weeks
  2.6.3 Can you answer these questions?

2.6.1 Top new questions this week

   How to cut a list by max sum
   Is it possible to ask Mathematica to stick two plots together to give a continuous plot ? (An example is given)
   ReplaceAll, Unexpected output
   Find All Permutations for Multiset
   Counting the number of edges between two graph partitions
   Summing over Partitions
   Incomplete web image scraping

How to cut a list by max sum

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234240

 {5, 10, 3, 8, 9, 8, 8, 4, 1, 7}

let maxsum=20, then I get ...

asked by wuyudi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68689 9 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 12 votes

Is it possible to ask Mathematica to stick two plots together to give a continuous plot ? (An example is given)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234373

I want to plot a function over a large range of \(x\). The problem is that for very large \(x\), even increasing PlotPoint to \(5\times 10^6\) and MaxRecursion 15, it does not give the whole result. But I ...

asked by charmin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74550 8 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 15 votes

ReplaceAll, Unexpected output

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234344

Each week I import a dataset, and every week the dataset differs in length (the number of records). After the import I need to do some transformations. One of these transformations is the ReplaceAll.

asked by Michiel van Mens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9590 7 votes

answered by Carl Woll https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45431 9 votes

Find All Permutations for Multiset

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234143

Take a list with repetitions, say {a, a, b, c}, and some permutation thereof, say {c, a, b, a}. I want to know which ...

asked by AccidentalFourierTransform https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34893 7 votes

answered by ciao https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=11467 6 votes

Counting the number of edges between two graph partitions

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234462

Consider the following:

g = RandomGraph[WattsStrogatzGraphDistribution[1000, 0.1, 5]] 
comm = FindGraphPartition[g, 2]; 
CommunityGraphPlot[g, comm]

asked by Caitlin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74961 5 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 5 votes

Summing over Partitions

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234302

Imagine I have a list of integers \(l=\{l_1,l_2,...,l_{50}\}\), say, for example

l = RandomInteger[10, 50]

and I want to find how many ways there are of summing ...

asked by sam wolfe https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=64001 5 votes

answered by Carl Woll https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45431 6 votes

Incomplete web image scraping

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234154

Occasionally when I scrape images from a webpage, such as:

Import["https://www.freeart.com/gallery/m/mondrian/mondrian.html", "Images"]

only a ...

asked by David G. Stork https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9735 5 votes

answered by Rohit Namjoshi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58370 4 votes

2.6.2 Greatest hits from previous weeks

   Positioning axes labels
   How to perform a multi-peak fitting?
   How to generate a random snowflake
   Figuring when the minute and hour hand coincide on a clock
   Is there an open source implementation of Mathematica-the-language?
   How to make a Spherical Cow?
   What’s the most difficult multidimensional integral that Mathematica has solved?

Positioning axes labels

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=87388

I need to change the position of my axes labels such that the y-axis label is in the middle and parallel to the y-axis. I’d also like the x-axis label to be in the middle of the x-axis rather than ...

asked by John_dydx https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7849 15 votes

answered by Virgil https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27697 16 votes

How to perform a multi-peak fitting?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=26336

I am wondering how to implement the multi-peak detecting and fitting in Mathematica. Following is an example of fitting the data using three peaks (such that the data ~ peak1 + peak2 + peak3). The ...

asked by Everett You https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1389 55 votes

answered by Silvia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=17 55 votes

How to generate a random snowflake

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=39361

'Tis the season...

And it’s about time I posed my first question on Mathematica Stack Exchange. So, here’s an holiday quest for you Graphics (and P-Chem?) gurus.

What is your best code for generating ...

asked by Peltio https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6745 140 votes

answered by Silvia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=17 181 votes

Figuring when the minute and hour hand coincide on a clock

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=573

I would like to list all possible times in a 12-hour period, where the hour hand overlaps the minute hand completely. This is really a question about three distinct things - to be done in Mathematica ...

asked by Steve D https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=191 15 votes

answered by Verbeia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8 21 votes

Is there an open source implementation of Mathematica-the-language?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=4454

I’ve seen questions before such as ”What is the best open-source equivalent for Mathematica?”, but that specific question (and that line of inquiry in general) cares more about the computer algebra ...

asked by sblom https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=178 122 votes

answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 85 votes

How to make a Spherical Cow?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=125043

Being a theoretical physicist, I always have a great respect for Spherical Cow. So I thought about making one myself. I am not sure how can I create (something considered to be the simplest!) this ...

asked by Sumit https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8070 69 votes

answered by andre314 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5467 76 votes

What’s the most difficult multidimensional integral that Mathematica has solved?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222184

I am interested in benchmarking numerical integration methods and am trying to develop a wider set of difficult multivariate examples. For my particular methods, I only want to look at non-negative-...

asked by ben18785 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19278 6 votes

2.6.3 Can you answer these questions?

   Solving \(E[abXab]=Y\) for Gaussian \((a,b)\)
   Problem with RunProcess
   Does NumberLinePlot give the whole results over a large domain? Or we need to increase its precision?

Solving \(E[abXab]=Y\) for Gaussian \((a,b)\)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234502

I have \(d/2\)-dimensional variables \(a,b\) jointly distributed as Gaussian(\(\mu ,\Sigma \)) in \(d\) dimensions, and need to solve the following equation for \(X\)

    T    T
E [ab  Xab  ] = Y

This is equivalent to ...

asked by Yaroslav Bulatov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=217 1 vote

Problem with RunProcess

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234260

I’m trying to use the RunProcess function to run docker on Mac OS using Mathematica. But there is a problem:

asked by Wei Li https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75601 1 vote

Does NumberLinePlot give the whole results over a large domain? Or we need to increase its precision?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234324

I use this code over the domain \(x\in (0,300)\)

asked by charmin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74550 1 vote

2.7 Thursday, November 5, 2020

  2.7.1 Top new questions this week
  2.7.2 Greatest hits from previous weeks
  2.7.3 Can you answer these questions?

2.7.1 Top new questions this week

   Why is there a discrepancy between JoinedCurve/FilledCurve and the underlying BSplineCurve segments?
   Converting an equation with units to one without units
   Generate an e machine graph from transition probability matrices
   Deconvolution approaches for 3D data
   construct a lattice with a defined unitcell
   How to remove Null plot markers in QuantilePlot?
   Split in non-overlapping sub-lists with elements within an interval from the first member

Why is there a discrepancy between JoinedCurve/FilledCurve and the underlying BSplineCurve segments?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233846

This may be related to How to discretize a BezierCurve?, but this question deals with BSplineCurves with specific SplineWeights, ...

asked by robjohn https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=232 10 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 8 votes

Converting an equation with units to one without units

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233804

I may have a solution but it is not slick! See below Doing numerical calculations with functions that use units can be very slow. I would like to have a function or operator that can turn my functions ...

asked by c186282 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4515 6 votes

answered by march https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29734 2 votes

Generate an e machine graph from transition probability matrices

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234036

I am trying to generate this type of graphic:

see Fig.1a from https://arxiv.org/abs/0905.3587. This process is associated with two transition matrices

asked by AG1123 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36275 6 votes

answered by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 7 votes

Deconvolution approaches for 3D data

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233877

Building neural nets in the WL is great. I was in the process of rewriting a previous GAN of mine in the WL to see if I can get better performance, and was surprised to find that the standard ...

asked by BBirdsell https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=49805 6 votes

construct a lattice with a defined unitcell

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233863

We can construct a base-centered tetragonal unit cell by: LatticeData["CenteredTetragonal", "Image"]

But how can we construct a lattice by

asked by Inzo Babaria https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=33967 6 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes

How to remove Null plot markers in QuantilePlot?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233816

Bug introduced in 12.0 and persisting in 12.1.1

I want to change the plot markers of the data points in QuantilePlot. This seems pretty straightforward:

asked by Q.P. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27119 6 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 5 votes

Split in non-overlapping sub-lists with elements within an interval from the first member

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233767

I want to split a large ordered list into consecutive non-overlapping sub-lists, such that all elements are within an interval from the first member of the sub-list . For example:

asked by Oleg https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75470 6 votes

answered by WReach https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=142 7 votes

2.7.2 Greatest hits from previous weeks

   Code that generates a mandala
   How to create word clouds?
   How can I draw the Olympic rings with Mathematica?
   Calling Correct Function for Plotting DiracDelta
   How to create effect like Van Gogh’s stroke brush?
   Parallel and perpendicular symbol from Mathematica to LaTeX
   Help find a bright object on Mars!

Code that generates a mandala

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=136974

My little brother asked me to print original mandalas for coloring. I would like some idea on how to create them, but without color, so he can color them.

asked by zeros https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26849 73 votes

answered by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 97 votes

How to create word clouds?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2334

Word clouds are rather useless fancy and visually appealing plots, where words are plotted with different sizes according to their frequency in a corpus. Many applications exist out there (Wordle, ...

asked by István Zachar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 145 votes

answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 119 votes

How can I draw the Olympic rings with Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8885

How can I draw the 5 interlocking Olympic rings with Mathematica? (SVG version) Edit

Hard choice, but some pretty cool answers here. I didn’t have 3D answers in mind when I posted the question, but ...

asked by Mike Honeychurch https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77 44 votes

answered by cormullion https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61 23 votes

Calling Correct Function for Plotting DiracDelta

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3506

I am wondering what is the correct function in Mathematica to plot the true impulse function, better known as the DiracDelta[] function. When using this inside of a ...

asked by night owl https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=116 17 votes

answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 19 votes

How to create effect like Van Gogh’s stroke brush?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=39003

I need to apply Van Gogh’s stroke brush effect to a random image Take the following image as an example:

Thank you so much if you could help!

asked by user10495 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10495 34 votes

answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 51 votes

Parallel and perpendicular symbol from Mathematica to LaTeX

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=46538

I want to get the following expression from Mathematica to LaTeX:

\[ \begin {bmatrix} E_{\parallel } \\ E_{\perp } \end {bmatrix} \]

I have tried to use inbuilt ’symbol’ character from the special ...

asked by Steve Hatcher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13314 19 votes answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 27 votes

Help find a bright object on Mars!

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11819

In today’s news, scientists found a bright object on one of Curiosity’s photos (it’s near the bottom of the picture below). It’s a bit tricky to find - I actually spent quite some time staring at the ...

asked by Victor K. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1351 198 votes

answered by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 257 votes

2.7.3 Can you answer these questions?

   How can I determine and then plot a confidence bands in QuantilePlot?
   How to remove the smallest term from asymptotic expansion?
   Solving the following system of integrodifferential equations: speed up of the code

How can I determine and then plot a confidence bands in QuantilePlot?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233931

Does anyone know if its possible to plot a confidence band in QuantilePlot? I haven’t been able to find any documentation for this, or a previous example on here.

asked by Q.P. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27119 3 votes

How to remove the smallest term from asymptotic expansion?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233823

It is well-known that \(e^{-1/x}\sim o(x^n)\) as \(x\to 0^+\) for any \(n\in \mathbb {N}\), thus if I do an asymptotic expansion for a function, say \(f=1/(1-x)+e^{-1/x}\) as \(x\to 0^+\), I expect to receive an ...

asked by user142288 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=59534 5 votes

Solving the following system of integrodifferential equations: speed up of the code

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233726

Consider a system of equations

asked by John Taylor https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=41058 1 vote

2.8 Thursday, October 29, 2020

  2.8.1 Top new questions this week
  2.8.2 Greatest hits from previous weeks
  2.8.3 Can you answer these questions?

2.8.1 Top new questions this week

   Dynamically drag graph vertices
   Display Number with SI prefixes
   Understanding the profiler: Is pattern matching/de-structuring expensive?
   How to select the fastest approach for large numerical data computations?
   Performance of pure function - Best way to define a function?
   Font style inconsistency on ”number sign” (hashtag) and ”at symbol”
   Solving a Nonlinear Complementary Problem (plasticity)

Dynamically drag graph vertices

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233409

Is it possible to make a dynamic graph with an ability to drag vertices? In other words let vertices behave like Locators and change its ...

asked by swish https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2490 9 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 13 votes

Display Number with SI prefixes

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233503

I have a number of val = 0.000015783 which represents a current value in Amps. I want to display it with 3 significant digits and with SI prefixes instead of the ...

asked by tobalt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27818 7 votes

answered by creidhne https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=41569 6 votes

Understanding the profiler: Is pattern matching/de-structuring expensive?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233388

I was profiling some code and I am trying to understand what the results mean. Suppose we have the very idiomatic,

asked by ITA https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42145 7 votes

How to select the fastest approach for large numerical data computations?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233677

I really love the flexibility of Mathematica: there are several ways to perform one task. However, to get the performance of the intense numeric calculation, it can ...

asked by Nam Nguyen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1712 6 votes

answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 7 votes

Performance of pure function - Best way to define a function?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233637

In general, to define a function, we often use f[x_]. Another way is to use pure function (full form and shorthand). I want to test the performance of these ...

asked by Nam Nguyen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1712 6 votes

Font style inconsistency on ”number sign” (hashtag) and ”at symbol”

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233665

Why number sign "#" (known as hashtag symbol on social media) or at sign "@" are not consistent with the ...

asked by azerbajdzan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53172 6 votes

answered by creidhne https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=41569 9 votes

Solving a Nonlinear Complementary Problem (plasticity)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233340

I would like to solve the following: given \(t\mapsto \sigma (t)\) and \(E>0\), \(\sigma _y>0\), find \(\epsilon \) such that:

asked by anderstood https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18767 5 votes

answered by xzczd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1871 4 votes

2.8.2 Greatest hits from previous weeks

   Crack CAPTCHA using deep learning
   Why I get the ”Set::write: ”Tag Times in is Protected.” error?
   What do the X and Y axis stand for in the Fourier transform domain?
   Where can I find examples of good Mathematica programming practice?
   How to calculate scalar curvature Ricci tensor and Christoffel symbols in Mathematica?
   How to add a front-end to the free Wolfram Engine?
   Plotting Complex Quantity Functions

Crack CAPTCHA using deep learning

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=143691

Deep convolutional neural networks are very good at computer vision related tasks. Optical Character Recognition (OCR) is one important branch of computer vision. In fact, the convolution neural ...

asked by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 87 votes

answered by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 98 votes

Why I get the ”Set::write: ”Tag Times in is Protected.” error?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11868

Why I get the error below with this code:

asked by Aurelius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1669 10 votes

answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 13 votes

What do the X and Y axis stand for in the Fourier transform domain?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=85139

In Wolfram Mathematica the function Fourier has the following declaration

Fourier[list]

And after a list is given to the ...

asked by user253956 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29958 27 votes

answered by Hugh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12558 61 votes

Where can I find examples of good Mathematica programming practice?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18

I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...

asked by J. M.’s discontentment https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 553 votes

answered by faysou https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66 486 votes

How to calculate scalar curvature Ricci tensor and Christoffel symbols in Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8895

I am seeking a convenient and effective way to calculate such geometric quantities. I’ve used packages like TensoriaCalc, but they don’t work at all time. Sometimes,...

asked by Zoe Rowa https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1713 40 votes

answered by Yi-Zen Chu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4869 18 votes

How to add a front-end to the free Wolfram Engine?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=198839

https://blog.stephenwolfram.com/2019/05/launching-today-free-wolfram-engine-for-developers/

http://www.wolfram.com/engine/

The Free Wolfram Engine for Developers is available for pre-production ...

asked by Alexey Golyshev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23402 63 votes

answered by Alexey Golyshev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23402 53 votes

Plotting Complex Quantity Functions

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3458

Trying to plot with complex quantities seems not to work properly in what I want to accomplish. I would like to know if there is a general rule/way of plotting when you have complex counterparts in ...

asked by night owl https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=116 42 votes

answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 29 votes

2.8.3 Can you answer these questions?

   How to define a derivative of a function at some point?
   Insufficient memory problem in Mathematica
   Classify; how UtilityFunction matrix is applied to resolve prediction?

How to define a derivative of a function at some point?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233672

Consider a function  derivative[x_]:=D[Sin[x],x]

When calling it with some argument, like derivative[2], instead of \(\cos (x)\) it gives me \(\partial _{2}\sin (2)\). Is ...

asked by John Taylor https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=41058 1 vote

Insufficient memory problem in Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233470

I am trying to initialize a 48600 x 48600 packed array from a sparse matrix and a diagonal matrix in Mathematica 8. If S1 is a sparsearray of that size then and S2 is list of 48600 length, then I am ...

asked by Roopayan Ghosh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=54433 4 votes

Classify; how UtilityFunction matrix is applied to resolve prediction?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233669

I can’t find any explanation about the details of the real computation, please anybody knows?

asked by pablo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61453 1 vote

2.9 Thursday, October 22, 2020

  2.9.1 Top new questions this week
  2.9.2 Greatest hits from previous weeks
  2.9.3 Can you answer these questions?

2.9.1 Top new questions this week

   How can I reproduce this mandala with Mathematica?
   Tennis Racket theorem
   Climbing/Descending the Integer Ladder
   Remove inner brackets
   Identify the Vertices and Lines around the edges of a free surface - Mesh/DiscreteGraphics
   How can I extract the edge points from an image?
   How to speed up integers finding function?

How can I reproduce this mandala with Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233050

I found this image on the Internet and it is very beautiful. How can I reproduce it? The ideal would be to be able to control the colors of the outside as well as the center.

asked by Susana https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=37778 12 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 32 votes

Tennis Racket theorem

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=232976

Torque-free Euler equations experiment seen in low gravity of Russian spacecraft is modelled here with a view to see its tumbling motion around the intermediate axis \(\omega _2\) rotation. However its ...

asked by Narasimham https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19067 10 votes

answered by Alex Trounev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58388 16 votes

Climbing/Descending the Integer Ladder

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233096

A fun combinatoric puzzle that’s popped up in my work that I think would be cute to have a Mathematica solution to, if anyone wants to give it a go. It’s basically a ladder climbing/descending problem ...

asked by b3m2a1 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=38205 8 votes

answered by Leonid Shifrin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=81 5 votes

Remove inner brackets

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233206

If I have the result

asked by GlomGive https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75305 7 votes

answered by wuyudi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68689 10 votes

Identify the Vertices and Lines around the edges of a free surface - Mesh/DiscreteGraphics

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=232975

To write a mesher that closes a mesh surface using an implied surface from a boundary spline curve and mesh generated using DiscreteGraphics, I need to identify the Vertices and Lines around the edges ...

asked by mh2000 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57215 7 votes

answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 8 votes

How can I extract the edge points from an image?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233092

I want to extract the edge points from a text image and use ListPlot[points] to visualize those points:

I tried to used ...

asked by vito https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=30288 7 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 9 votes

How to speed up integers finding function?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=232960

Playing with integers I looked for a way of finding, let’s say, \(4\)-digits positive integers such that \(a,b,a+b\) had the same digits, like

1089 + 8019 = 9108

I am a newbie and I used this function

asked by Raffaele https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=49764 7 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 12 votes

2.9.2 Greatest hits from previous weeks

   Where can I find examples of good Mathematica programming practice?
   Plotting a Phase Portrait
   How can I save both the plot and the legend together?
   Find eigen energies of time-independent Schrödinger equation
   xkcd-style Plots
   How to create a new ”person curve”?
   How to plot an ellipse?

Where can I find examples of good Mathematica programming practice?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18

I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...

asked by J. M.’s discontentment https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 553 votes

answered by faysou https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66 486 votes

Plotting a Phase Portrait

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=14160

I’m trying to plot a phase portrait for the differential equation

x′′ − (1 − x2)x′ + x = 0.5cos(1.1t).

The primes are derivatives with respect to \(t\). I’ve reduced this second order ODE to ...

asked by covertbob https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4528 38 votes

answered by David Slater https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1746 33 votes

How can I save both the plot and the legend together?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=35653

In this example, how can I put the legend inside the graph? Currently, when I save the graph, only the graph is saved, not the legend.

asked by Mika Ike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6543 42 votes

answered by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 38 votes

Find eigen energies of time-independent Schrödinger equation

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=32293

I’m trying to get the eigenvalues of a one dimensional time-independent Schrödinger equation,

\(-\frac {h^2}{2m_0}\frac {d^2\psi }{dx^2}+U(x)~\psi =Ei~\psi \)

where U(x) is some potential and Ei is the ...

asked by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 48 votes

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 46 votes

xkcd-style Plots

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11350

I received an email to which I wanted to respond with a xkcd-style graph, but I couldn’t manage it. Everything I drew looked perfect, and I don’t have enough command over ...

asked by Amatya https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2039 616 votes

answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 474 votes

How to create a new ”person curve”?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=17704

Wolfram—Alpha has a whole collection of parametric curves that create images of famous people. To see them, enter WolframAlpha[”person curve”] into a Mathematica ...

asked by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 83 votes

answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 45 votes

How to plot an ellipse?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=20100

I’m new to Mathematica, and I’m finding it difficult to plot an ellipse. I tried using

Plot[(x/5)^2 + (y/3)^2 == 1, {x, -5, 5}, {y, -3, 3}]

but I’m getting ...

asked by Sriram https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6075 17 votes

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 29 votes

2.9.3 Can you answer these questions?

   Equation of Motion: Perturb Scalar Field and flat FLRW Metric (xAct)
   Is there any way to change the box-formatting behavior thoroughly?
   How to get colors at points in Graphics3D?

Equation of Motion: Perturb Scalar Field and flat FLRW Metric (xAct)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233105

Is there a way to get the equations of motion (eom) of a scalar field from a Lagrangian in a perturbed FLRW metric? I want to perturb the field as well as the metric to 1st order. What I did so far:

asked by kalle https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68748 1 vote

Is there any way to change the box-formatting behavior thoroughly?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233100

Background The box-formmating behavior is affected by the downvalues of the symbol MakeBoxes. But the formatting behavior is not exactly ...

asked by asd1dsa https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72876 2 votes

How to get colors at points in Graphics3D?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233287

To get the color at a 2D point in Graphics you can Rasterize it and look up the pixel value, but not for ...

asked by M.R. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=403 2 votes

2.10 Thursday, October 15, 2020

  2.10.1 Top new questions this week
  2.10.2 Greatest hits from previous weeks
  2.10.3 Can you answer these questions?

2.10.1 Top new questions this week

   How can I plot my financial indicator below a trading chart (produced by TradingChart) with the same x-axis?
   Adding elements of second list in succession
   Has the Undo command really been settled? On version 12.1 it only works sporadically. What are some reasons it drops steps?
   Solving heat equation on a cylinder with insulated ends and convective boundary conditions
   Converting a RawBoxes object to a workable expression
   Mean age of people
   Suggestion bar still causing Kernel crashes?

How can I plot my financial indicator below a trading chart (produced by TradingChart) with the same x-axis?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=231660

Since this question was not answered, I would like to ask again with some additional information. I have a trading chart saved as chart1 as follows.

asked by DLT https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=54107 9 votes

answered by Lukas Lang https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36508 6 votes

Adding elements of second list in succession

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=231695 Given

t1 = {{1, 2}, {3, 4}}; 
t2 = {{a, b, c}, {e, f}};

I want to add in succession elements of list 2 to list 1 to get:

asked by user57467 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57467 7 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 8 votes

Has the Undo command really been settled? On version 12.1 it only works sporadically. What are some reasons it drops steps?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=231523

Although Undo has been around since version 10 (before my time) I’ve noticed that sometimes it works just fine up to the moment of the last ...

asked by Jules Manson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=37721 7 votes

Solving heat equation on a cylinder with insulated ends and convective boundary conditions

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=231588

I am trying to solve heat equation on a cylinder whose ends are thermally insulated and its circular face is exposed to convection. Therefore I have Neumann boundary condition on all faces of the ...

asked by Deep https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44615 7 votes

answered by yawnoc https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72028 5 votes

Converting a RawBoxes object to a workable expression

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=232789

I have manged to turn an image into a RawBoxes expression. How do I turn in back into something I can use in Graphics In ...

asked by Hugh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12558 6 votes

answered by Carl Woll https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45431 9 votes

Mean age of people

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=232809

I have the following datas:

I want to find mean age by using following formula,

Any way to do this in general in Mathematica easily.

asked by Jasmine https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73364 6 votes

answered by xzczd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1871 12 votes

Suggestion bar still causing Kernel crashes?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=232784

On Mathematica 12.1.1, Windows 10. When Suggestions bar is active, entering and evaluating the following crashes the Kernel.

asked by ciao https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=11467 6 votes

2.10.2 Greatest hits from previous weeks

   How to express trigonometric equation in terms of of given trigonometric function?
   Elegant operations on matrix rows and columns
   What do the X and Y axis stand for in the Fourier transform domain?
   Figuring when the minute and hour hand coincide on a clock
   Code that generates a mandala
   How to generate a random snowflake
   Extract real part of a complex expression better than Re does

How to express trigonometric equation in terms of of given trigonometric function?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=434

How can I express a trigonometric equation / identity in terms of a given trigonometric function?

using following trigonometric identities

asked by Prashant Bhate https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=99 30 votes

answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 37 votes

Elegant operations on matrix rows and columns

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3069

Question

The Mathematica tutorial has a section ’Basic Matrix Operations’, describing operations like transpose, inverse and determinant. These operations all work on entire matrices. I am missing a ...

asked by sjdh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=515 180 votes

answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 60 votes

What do the X and Y axis stand for in the Fourier transform domain?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=85139

In Wolfram Mathematica the function Fourier has the following declaration

Fourier[list]

And after a list is given to the ...

asked by user253956 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29958 27 votes

answered by Hugh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12558 61 votes

Figuring when the minute and hour hand coincide on a clock

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=573

I would like to list all possible times in a 12-hour period, where the hour hand overlaps the minute hand completely. This is really a question about three distinct things - to be done in Mathematica ...

asked by Steve D https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=191 15 votes

answered by Verbeia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8 21 votes

Code that generates a mandala

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=136974

My little brother asked me to print original mandalas for coloring. I would like some idea on how to create them, but without color, so he can color them.

examples

asked by zeros https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26849 72 votes

answered by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 95 votes

How to generate a random snowflake

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=39361

’Tis the season...

And it’s about time I posed my first question on Mathematica Stack Exchange. So, here’s an holiday quest for you Graphics (and P-Chem?) gurus.

What is your best code for generating ...

asked by Peltio https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6745 140 votes

answered by Silvia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=17 181 votes

Extract real part of a complex expression better than Re does

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3306

I have a complex expression with real positive variables only.

Mathematica Input Style:

asked by max https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=796 33 votes

answered by nixeagle https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=814 52 votes

2.10.3 Can you answer these questions?

   Passing input from a textfile into a function
   How to get the coefficients of second-order Runge-Kutta formula coherently?
   Taking ”intermediate” limits, e.g. \({\cal X}\to 0\) but \({\cal X}/\epsilon \to \infty \) as \(\epsilon \to 0\) - *without* taking \(\epsilon \to 0\) directly

Passing input from a textfile into a function

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=231540

I have a text file which is a list of numbers and would like to pass each number in the list as input to a Mathematica function. For example, my text might contain [2, 1, 4], and I would like to pass ...

asked by Joshua Steier https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75099 1 vote

How to get the coefficients of second-order Runge-Kutta formula coherently?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=231528

The form of the second order Runge Kutta formula is as follows(the following is from page 287 of this book):

asked by A little mouse on the pampas https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42417 1 vote

Taking ”intermediate” limits, e.g. \({\cal X}\to 0\) but \({\cal X}/\epsilon \to \infty \) as \(\epsilon \to 0\) - *without* taking \(\epsilon \to 0\) directly

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=232859 I have an expression that I would like to take limits of but not in a conventional sense. Take for example, an expression like

This expression involves intermediate variables

asked by epsilonD3LT4 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75082 1 vote

2.11 Thursday, October 1, 2020

  2.11.1 Top new questions this week
  2.11.2 Greatest hits from previous weeks
  2.11.3 Can you answer these questions?

2.11.1 Top new questions this week

   What is a good way of perfoming operations on specified columns of a table with many columns
   Quickest way to test whether array is constant
   Solving a rotating combination lock puzzle
   Shortest way to make a checkerboard pattern
   Smoothing the Region?
   How to replace only the isolated variable x?
   Counting Elements in Multiple Lists

What is a good way of perfoming operations on specified columns of a table with many columns

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230854

If I have a table of data and I want to do a specific operation on say the third column, I usually do something like this:

asked by Q.P. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27119 11 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 8 votes

Quickest way to test whether array is constant

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230971

At the moment I use Length[ DeleteDuplicates[ array ] ] == 1 to check whether an array is constant, but I’m not sure whether this is optimal. What would be the ...

asked by Gert https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27889 11 votes

answered by Sjoerd Smit https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=43522 9 votes

Solving a rotating combination lock puzzle

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230749

The following puzzle appears in The House of da Vinci II and I thought it might be interesting to tackle in Mathematica:

There are numbers marked on four rotating cylinders. These numbers must add up ...

asked by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 9 votes

answered by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 8 votes

Shortest way to make a checkerboard pattern

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230988

I’m looking for the shortest (in terms of characters) code snippet to make an n-square checkerboard. Here’s my first try (comes in at 72 characters):

asked by M.R. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=403 7 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 9 votes

Smoothing the Region?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230725

There is a 2D Pi

I successed transformed it to 3D.

asked by partida https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=15961 7 votes

answered by xzczd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1871 9 votes

How to replace only the isolated variable x?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230717

I want to replace the variable x in the result, not x in unrelated x[i]

asked by A little mouse on the pampas https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42417 7 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 11 votes

Counting Elements in Multiple Lists

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230864

How to build a table that counts how many times each element in mainlist occurs in lst1, lst2, lst3, lst4 and which lst1, lst2, lst3, lst4 contains that element. For example, in mainlist, element ...

asked by PRG https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42700 6 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes

2.11.2 Greatest hits from previous weeks

   What does # mean in Mathematica?
   Where can I find examples of good Mathematica programming practice?
   How do I identify the source of a ”Tag times protected” error?
   How to create a new ”person curve”?
   Mathematica 10.0.x freezes in Initializing kernels
   Extract real part of a complex expression better than Re does
   Calculate the 2D Fourier transform of an Image

What does # mean in Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19035

I asked Mathematica to compute the following

Solve[c (1-x)^2-x^(1/4) == 0, x] 
 
and it returned this: 
  x = Root[#1^8 c^4 - 8 #1^7 c^4 + 28 #1^6 c^4 - 56 #1^5 c^4 ...

asked by ronanymous https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5730 37 votes

answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 64 votes

Where can I find examples of good Mathematica programming practice?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18

I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...

asked by J. M.’s discontentment https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 550 votes

answered by faysou https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66 484 votes

How do I identify the source of a ”Tag times protected” error?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11982

I have some code that looks like

Table[ 
    a = 1; 
    b = {2, 3} 
    c = i;, 
    {i, 2} 
] 
 
which gives an error: 
  Set::write: Tag Times in c {2,3} is Protected....

asked by dearN https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=204 28 votes

answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 35 votes

How to create a new ”person curve”?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=17704

Wolfram—Alpha has a whole collection of parametric curves that create images of famous people. To see them, enter WolframAlpha["person curve"] into a Mathematica ...

asked by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 83 votes

answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 45 votes

Mathematica 10.0.x freezes in Initializing kernels

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=92931

Bug caused by paclet update and fixed by paclet update.

I updated to Windows 10 and have been running Mathematica fine on it for over a month. For some reason, it has just stopped working. I don’t ...

asked by mitcheljh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6783 80 votes

answered by ilian https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=145 101 votes

Extract real part of a complex expression better than Re does

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3306

I have a complex expression with real positive variables only.

Mathematica Input Style:

asked by max https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=796 33 votes

answered by nixeagle https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=814 52 votes

Calculate the 2D Fourier transform of an Image

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=29203

I am new to Mathematica, and using version 8.0.

I would like to calculate the 2D Fourier Transform of an Image with Mathematica and plot the magnitude and phase ...

asked by user8727 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8727 15 votes

answered by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 32 votes

2.11.3 Can you answer these questions?

   Simplify Equation with variable unequal to zero
   finding primes using chebyshev bias
   Why does NDSolve not give consistent results?

Simplify Equation with variable unequal to zero

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230846

How can I simplify the following equation with Mathematica assuming z!=0? I have the following code:

asked by Franz Ferdinand https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74882 1 vote

finding primes using chebyshev bias

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230943

Using the problem from my previous question link. For each n, that is n= \(10^3\) to \(10^6\) with a ten-fold increase, how do I use Chebyshev Bias to display the number of primes (which are in the ...

asked by complab56 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74866 1 vote

Why does NDSolve not give consistent results?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230784

This is my code:

asked by S.J.E. Huisman https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74858 1 vote

2.12 Thursday, September 24, 2020

  2.12.1 Top new questions this week
  2.12.2 Greatest hits from previous weeks
  2.12.3 Can you answer these questions?

2.12.1 Top new questions this week

   Solving the Lotka-McKendrick model with NDSolve
   Nonlinear dispersal equation modeling insect aggregation
   Making a faster alternative for PatternSequence
   How can I get material property data past what’s provided via ElementData?
   DSolve does not return solution to simple system of second order PDEs
   Build the following symmetric array
   Evaluate section by button click

Solving the Lotka-McKendrick model with NDSolve

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230366

The Lotka-McKendrick model is a demographic model that represents the way a population changes over time due to fertility and mortality. For an age-specific population density \( u(a, t) \), and a total ...

asked by Pillsy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=531 12 votes

answered by Chris K https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6358 9 votes

Nonlinear dispersal equation modeling insect aggregation

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230429

I’m a newbie with Mathematica, I know it’s a basic answer, but I can’t solve the problem on my own. I have the following equation reflecting insect aggregation at low population densities (taken from ...

asked by Vefhug https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74729 10 votes

answered by xzczd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1871 17 votes

Making a faster alternative for PatternSequence

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230622

I need to improve a pattern or switch an approach. It is best described by an example For a hierarchy/order given by a list e.g.:

order = {1, 2, 3}

and a list:

asked by Kuba https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5478 9 votes

answered by Leonid Shifrin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=81 9 votes

How can I get material property data past what’s provided via ElementData?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230484

Background Let’s say I want information (e.g. bulk modulus or space group) on an element or chemical compound that isn’t available via e.g. ElementData[]

asked by Sterling https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61736 6 votes

answered by Sterling https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61736 6 votes

DSolve does not return solution to simple system of second order PDEs

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230383

I’m trying to solve a simple system of second order PDEs with Mathematica 11.1. Here is the system:

asked by C. B. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74734 6 votes

answered by bbgodfrey https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1063 3 votes

Build the following symmetric array

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230650

My mind is a bit cloudy and I can’t quite pinpoint the pattern here that will allow me to write an elegant piece of code to build the following symmetric matrix of for a given size ...

asked by QuantumDot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2048 5 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 4 votes

Evaluate section by button click

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230613

I have a section in my notebook devoted to unit testing, since I’m not comfortable to use the built-in system. I’d like to evaluate the entire section by button click. But I get lost in the notebook ...

asked by infinitezero https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=31036 5 votes

answered by Kuba https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5478 5 votes

2.12.2 Greatest hits from previous weeks

   Assign the results from a Solve to variable(s)
   Finding unit tangent, normal, and binormal vectors for a given r(t)
   Multivariable Taylor expansion does not work as expected
   xkcd-style Plots
   What’s the most difficult multidimensional integral that Mathematica has solved?
   Drawing a square root spiral
   Get a ”step-by-step” evaluation in Mathematica

Assign the results from a Solve to variable(s)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=6669

I understand Mathematica can’t assign the results of a Solve to the unknowns because there may be more than 1 solution. How can I assign the 4 values of following result to variables?

asked by stevenvh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1450 56 votes

answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 34 votes

Finding unit tangent, normal, and binormal vectors for a given r(t)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18598

For my Calc III class, I need to find \(T(t), N(t)\), and \(B(t)\) for \(t=1, 2\), and \(-1\), given \(r(t)=\{t,t^2,t^3\}\).

I’ve got Mathematica, but I’ve never used it before and I’m not sure how to coerce ...

asked by a98 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5605 30 votes

answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 43 votes

Multivariable Taylor expansion does not work as expected

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=15023

The basic multivariable Taylor expansion formula around a point is as follows:

f(r + a) = f(r)+ (a⋅∇ )f(r)+  1-(a ⋅∇ )
                              2!

asked by matheorem https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4742 58 votes

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 65 votes

xkcd-style Plots

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11350

I received an email to which I wanted to respond with a xkcd-style graph, but I couldn’t manage it. Everything I drew looked perfect, and I don’t have enough command over ...

asked by Amatya https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2039 615 votes

answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 474 votes

What’s the most difficult multidimensional integral that Mathematica has solved?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222184

I am interested in benchmarking numerical integration methods and am trying to develop a wider set of difficult multivariate examples. For my particular methods, I only want to look at non-negative-...

asked by ben18785 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19278 6 votes

Drawing a square root spiral

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=66969

Here is a start. I’m looking for a nice way to draw it.

asked by matrix89 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5379 24 votes

answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 21 votes

Get a ”step-by-step” evaluation in Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=148

Is it possible in Mathematica to get a step-by-step evaluation of some functions; that’s to say, outputting not only the result but all the stages that have led to it? If so, how does one do it?

asked by Cydonia7 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44 125 votes

answered by J. M.’s discontentment https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 105 votes

2.12.3 Can you answer these questions?

   How can I make NDSolve aware of vectorial nature of an ODE?
   NDsolve Boundary Condition is a Function of the Solution
   Optimizing a graph-theoretic piece of code

How can I make NDSolve aware of vectorial nature of an ODE?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230550

I am trying to solve the equilibrium equation \(\text {DIV } \mathbf P(\textbf {u}(x,y)) = \mathbf {f}\), where \(\mathbf P\) is the stress tensor defined by

P = F + (1−  detF)

asked by rmk236 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74782 1 vote

NDsolve Boundary Condition is a Function of the Solution

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230520

I am trying to solve something like Fick’s Law using NDSolve

∂φ    ∂2φ
---=  --2-+ F (r,t)
∂t    ∂r

Subject to a ...

asked by UranylTrioxide https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74775 1 vote

Optimizing a graph-theoretic piece of code

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230425

I have written the following piece of code:

asked by Mr. Mister https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74745 2 votes

2.13 Thursday, September 17, 2020

  2.13.1 Top new questions this week
  2.13.2 Greatest hits from previous weeks
  2.13.3 Can you answer these questions?

2.13.1 Top new questions this week

   Display hexagon grid to visualize Langton’s ant
   Position function error
   Mathematica 12.1.0.0 exporting low quality images at high ImageResolution
   How can I count the color pixels in each partition of the image
   Why does Nearest not return both equally distant values?
   BarChart does not display asymmetric error bars correctly
   Pattern-matching complex numbers as a + bi

Display hexagon grid to visualize Langton’s ant

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230017

I am looking to recreate the following image from this reference as

using Mathematica’s Polygon documentation under ”Applications” as a starting point. I want to eventually use Mathematica ...

asked by C. Fuhrman https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=60593 10 votes

answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 8 votes

Position function error

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230018

I recently upgraded from Mathematica 6 to the most recent version. In my new version the Position function returns strange results that were not present in the old ...

asked by Peter https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74626 8 votes

answered by ciao https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=11467 11 votes

Mathematica 12.1.0.0 exporting low quality images at high ImageResolution

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229973

I recently upgraded from Mathematica 11 to Mathematica 12.1.0.0 . I understand there were some UI changes to accommodate high resolution monitors. I’m not sure if this issue is related to that. I am ...

asked by user3556814 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74618 8 votes

answered by Piotr Wendykier https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9239 1 vote

How can I count the color pixels in each partition of the image

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230060

I have a image of 1000 x 1000 pixels of which I have made 5 x 5 partitions. After that I am looking for a way to count number of color pixels in each partition. Thanks in advance for help.

asked by Atique Khan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=59972 7 votes

answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 4 votes

Why does Nearest not return both equally distant values?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230082

Define the following three vectors:

a = {0., 0., 0.}; 
b = {-0.5`, 0.4330127018922193`, 0.25`}; 
c = {-0.5`, 0.`, 0.`};

Note that the distance from a to c is the ...

asked by abwatson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1709 7 votes

answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 5 votes

BarChart does not display asymmetric error bars correctly

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230145

BarChart seems to read the uncertainty in elements the other way around. The object: Around[5, {1, 10}] is evaluated as . However, when you use it in a BarChart, the uncertainties are swapped:

asked by Luis https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=24933 6 votes

Pattern-matching complex numbers as a + bi

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230013

I just started working with Mathematica and am toying with pattern matching. There may be something obvious I’m missing in this, but I can’t figure it out by myself. I want to write down a function ...

asked by ppln https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69266 6 votes

answered by eyorble https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=52935 5 votes

2.13.2 Greatest hits from previous weeks

   Plot, extract data to a file
   How to calculate scalar curvature Ricci tensor and Christoffel symbols in Mathematica?
   How can I improve Mathematica’s resolution on a macbook retina display?
   Code that generates a mandala
   How to create effect like Van Gogh’s stroke brush?
   Find eigen energies of time-independent Schrödinger equation
   How to find the position of elements in a list satisfying criteria

Plot, extract data to a file

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19859

I need to save data that Mathematica uses inside the Plot command. The format that I would like to have is:

x1 y1 
x2 y2 
.....

asked by molkee https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5097 30 votes

answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 47 votes

How to calculate scalar curvature Ricci tensor and Christoffel symbols in Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8895

I am seeking a convenient and effective way to calculate such geometric quantities. I’ve used packages like TensoriaCalc, but they don’t work at all time. Sometimes,...

asked by Zoe Rowa https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1713 38 votes

answered by Yi-Zen Chu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4869 18 votes

How can I improve Mathematica’s resolution on a macbook retina display?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18419

Mathematica 9.0 looks a bit fuzzy on the retina screen, how can I increase the resolution? Here another screenshot showing a direct comparison between the browser and Mathematica

asked by Tom Wellington https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2437 44 votes

Code that generates a mandala

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=136974

My little brother asked me to print original mandalas for coloring. I would like some idea on how to create them, but without color, so he can color them.

examples

asked by zeros https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26849 71 votes

answered by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 95 votes

How to create effect like Van Gogh’s stroke brush?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=39003

I need to apply Van Gogh’s stroke brush effect to a random image Take the following image as an example:

Thank you so much if you could help!

asked by user10495 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10495 34 votes

answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 51 votes

Find eigen energies of time-independent Schrödinger equation

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=32293

I’m trying to get the eigenvalues of a one dimensional time-independent Schrödinger equation,

\(-\frac {h^2}{2m_0}\frac {d^2\psi }{dx^2}+U(x)~\psi =Ei~\psi \)

where \(U(x)\) is some potential and Ei is the ...

asked by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 48 votes

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 46 votes

How to find the position of elements in a list satisfying criteria

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=180

Say I have a list x={2,4,6,8,10} and I want to find out the positions of the elements that are greater than 7.

asked by PeterR https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=140 66 votes

answered by J. M.’s discontentment https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 63 votes

2.13.3 Can you answer these questions?

   Faster alternative to ImageCorrespondingPoints?
   How to make this expression?

Faster alternative to ImageCorrespondingPoints?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229962

I’m trying to use ImageCorrespondingPoints to register frames in a video sequence. Computational speed is an important consideration for the application I am ...

asked by Brady Hunt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9017 2 votes

How to make this expression?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230052

How to code this expression in WolframAlpha. I am interested in how to code the second sum, because it contains a boolean expression:

1∑00∑
      xixj
i=1j>n

asked by Andrey Stebenkov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74632 1 vote

2.14 Thursday, September 10, 2020

  2.14.1 Top new questions this week
  2.14.2 Greatest hits from previous weeks
  2.14.3 Can you answer these questions?

2.14.1 Top new questions this week

   Can we use Mathematica to design an electronic active filter?
   How to mesh a French biscuit (modulated ellipsoid)
   Solutions for searching over Mathematica notebooks?
   Coordinate-free derivative
   Please explain this syntax: GaborWavelet[6][”FourierFactor”]
   How to select several columns from a dataset
   BarLegend ticks distorted in MatrixPlot

Can we use Mathematica to design an electronic active filter?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229714

How can we use Mathematica to design an electronic implementation of an active filter?

asked by David Keith https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44700 19 votes

answered by David Keith https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44700 22 votes

How to mesh a French biscuit (modulated ellipsoid)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229535

I would like to create a boundary mesh of the following ellipsoid, whose thickness is modulated along its long axis:

The surface parametrization I used for it is:

asked by Oscillon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13605 10 votes

answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 10 votes

Solutions for searching over Mathematica notebooks?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229522

I have hundreds of Mathematica notebooks accumulated over the years, and I’d like to search over them. I’ve been using various versions of text search (grep, SilverSearcher, Spotlight), but there are ...

asked by Yaroslav Bulatov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=217 10 votes

answered by Chris Degnen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=363 11 votes

Coordinate-free derivative

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229703

Given the function

         v
f : v ↦→ ∥v∥,

I would like to compute the derivative of \(f\), that is \(df(v)\). It is possible to derive it by hand, which leads to

asked by anderstood https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18767 9 votes

Please explain this syntax: GaborWavelet[6][”FourierFactor”]

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229853

I’ve been using Mathematica for some years, yet I’m befuddled by this statement: GaborWavelet[6]["FourierFactor"]

It appears to give the center frequency ...

asked by Chris https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66733 7 votes

answered by Carl Woll https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45431 11 votes

How to select several columns from a dataset

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229678

I have a dataset with 20 columns. For a analysis I need all columns except the columns 9 and 11. What I do is:

asked by Michiel van Mens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9590 7 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 9 votes

BarLegend ticks distorted in MatrixPlot

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229502

As shown in many threads here (this, this, ...), Ticks is a valid option of BarLegend.

But it doesn’t seem to work well in this ...

asked by xiaohuamao https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=11125 7 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 8 votes

2.14.2 Greatest hits from previous weeks

   Help find a bright object on Mars!
   Extract real part of a complex expression better than Re does
   Solving \(L=\frac {3}{2} \sqrt {4 \pi ^2 A^2+W^2}-\frac {\sqrt {5 W \sqrt {4 \pi ^2 A^2+W^2}+6 \pi ^2 A^2+3 W^2}}{\sqrt {2}}+\frac {3 W}{2}\) for \(W\)
   How to ask Mathematica to imitate Andy Warhol’s pop-art painting?
   Cutting bagels into linked halves
   How to generate a random snowflake
   Finding unit tangent, normal, and binormal vectors for a given r(t)

Help find a bright object on Mars!

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11819

In today’s news, scientists found a bright object on one of Curiosity’s photos (it’s near the bottom of the picture below). It’s a bit tricky to find - I actually spent quite some time staring at the ...

asked by Victor K. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1351 198 votes

answered by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 257 votes

Extract real part of a complex expression better than Re does

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3306

I have a complex expression with real positive variables only.

Mathematica Input Style:

asked by max https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=796 33 votes

answered by nixeagle https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=814 52 votes

Solving \(L=\frac {3}{2} \sqrt {4 \pi ^2 A^2+W^2}-\frac {\sqrt {5 W \sqrt {4 \pi ^2 A^2+W^2}+6 \pi ^2 A^2+3 W^2}}{\sqrt {2}}+\frac {3 W}{2}\) for \(W\)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=57763

When I solve the aforementioned equation for \(W\) or \(A\) on Mathematica I get a long and ugly equation in return, namely one of the solutions for \(W\) is: (attempt to read at your own health)

asked by J.D’Almbert https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19257 8 votes

answered by Alexei Boulbitch https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=788 15 votes

How to ask Mathematica to imitate Andy Warhol’s pop-art painting?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=59132

I tried to ask Mathematica to imitate Andy Warhol, let it convert a Marilyn Monroe’s portrait so that it looks like Warhol’s world famous pop-art painting.

However, the result shown below is far from ...

asked by Putterboy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=16069 50 votes

answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 65 votes

Cutting bagels into linked halves

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=7545

I recently came across this video: Mathematically correct breakfast, which shows how a bagel can be neatly sliced into two identical linked halves. I’d like to try this with Mathematica. Here’s a ...

asked by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 62 votes

answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 76 votes

How to generate a random snowflake

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=39361

’Tis the season... And it’s about time I posed my first question on Mathematica Stack Exchange. So, here’s an holiday quest for you Graphics (and P-Chem?) gurus.

What is your best code for generating ...

asked by Peltio https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6745 140 votes

answered by Silvia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=17 181 votes

Finding unit tangent, normal, and binormal vectors for a given r(t)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18598

For my Calc III class, I need to find \(T(t), N(t)\), and \(B(t)\) for \(t=1, 2\), and \(-1\), given \(r(t)=\{t,t^2,t^3\}\).

I’ve got Mathematica, but I’ve never used it before and I’m not sure how to coerce ...

asked by a98 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5605 30 votes

2.14.3 Can you answer these questions?

   Solving equations over unknown Domains
   Not able to globalize variables from a manipulate expression
   force maximum simplification of radicals in a traditional way-How to do it?

Solving equations over unknown Domains

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229778

I am trying to solve for what values of some variables make some expressions true; not exactly equations. For a toy example, I am trying to solve for all values of \(x\) that make \(4x\) an Integer.

asked by Matthew Crawford https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=51196 1 vote

Not able to globalize variables from a manipulate expression

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229534

I am attempting to globalize the variables inside of a Manipulate expression for which my variables are also using interdependent controls. I have attempted to use

asked by Ryan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74490 1 vote

force maximum simplification of radicals in a traditional way-How to do it?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229660

this should be simple but I can’t get mathematica to simplify a radical or a set of radicals and express them in the traditional way for example by simplifying this

asked by BeTDa https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72885 2 votes

answered by Daniel Huber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46318 0 votes

2.15 Thursday, September 3, 2020

  2.15.1 Top new questions this week
  2.15.2 Greatest hits from previous weeks
  2.15.3 Can you answer these questions?

2.15.1 Top new questions this week

   Is it possible to call back to Mathematica when using Python through ExternalEvaluate?
   Camera view along the trajectory
   How to select 2 pairs of distinct twins form a list of 4-tuples?
   Combine two plots with reversed y-axis
   Can this probability function speed be improved?
   Embed a rose flower image in 3D space with axes labeled in UTF8
   Simplify Nested Lists

Is it possible to call back to Mathematica when using Python through ExternalEvaluate?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229164

makes it possible to call Python code from Mathematica. The Wolfram Client for Python makes it possible to call Mathematica from Python. When using ...

asked by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 8 votes

answered by Riccardo Di Virgilio https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=51868 3 votes

Camera view along the trajectory

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229242

I want to create an animation like this one: https://www.youtube.com/watch?v=rvzZmNW2_70 After googling I have found just below informations about this issue: https://twitter.com/bencbartlett/status/...

asked by Mustafa Kosem https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74423 7 votes

answered by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 6 votes

How to select 2 pairs of distinct twins form a list of 4-tuples?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229409

Given a list of 4-tuples as follows. data = Tuples[Range@6, 4]; I want to select any 4-tuples with two pairs of different twins, for example, as follows:

asked by Wissen Macht Frei https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42141 6 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 3 votes

Combine two plots with reversed y-axis

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229128

I need to display two y-values for a list of points. I tried doing this:

asked by Rodrigo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=43431 6 votes

answered by LouisB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=22158 4 votes

Can this probability function speed be improved?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229239

I have a process that as part of it requires a certain probability query, specifically, given a multinomial distribution with f equiprobable categories and r trials, some specific category has a given ...

asked by ciao https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=11467 5 votes

answered by JimB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19758 4 votes

Embed a rose flower image in 3D space with axes labeled in UTF8

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229299

I am trying to create an image in which a rose flower image in a 3D space with axes labeled in UTF8! Labels don’t render correctly and not sure how to put the image at say the original of XYZ space.

asked by chikitin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74442 4 votes

answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 4 votes

Simplify Nested Lists

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229427

I have a problem with nested lists. For example, i have this list:

asked by aptmess https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58120 4 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes

2.15.2 Greatest hits from previous weeks

   How can I plot implicit equations?
   My Girlfriend is going to prison...Save her with Math
   Image processing: Floor plan - detecting rooms’ borders (area) and room names’ texts
   Crack CAPTCHA using deep learning
   Solving \(L=\frac {3}{2} \sqrt {4 \pi ^2 A^2+W^2}-\frac {\sqrt {5 W \sqrt {4 \pi ^2 A^2+W^2}+6 \pi ^2 A^2+3 W^2}}{\sqrt {2}}+\frac {3 W}{2}\) for \(W\)
   Entering numbers in Scientific Notation?
   Finding unit tangent, normal, and binormal vectors for a given r(t)

How can I plot implicit equations?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=34668

If you enter the following into Wolfram — Alpha, you get nice graphs:

graph 4 x^4 + y^2 = 2  How do you do this in Mathmatica? I realize that these are not ...

asked by Rollie https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10174 36 votes

answered by Timothy Wofford https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9391 38 votes

My Girlfriend is going to prison...Save her with Math

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=135937

Salacious title, but true story.

asked by Prisoners Dilema https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46025 42 votes

answered by bobthechemist https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7167 23 votes

Image processing: Floor plan - detecting rooms’ borders (area) and room names’ texts

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19546

Here is a simple building floor plan. I would like to derive the rooms as (rectangular) components and the names of the rooms. This is very common representation of building floor plans.

The problem

asked by s.s.o https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=840 64 votes

answered by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 59 votes

Crack CAPTCHA using deep learning

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=143691

Deep convolutional neural networks are very good at computer vision related tasks. Optical Character Recognition (OCR) is one important branch of computer vision.

In fact, the convolution neural ...

asked by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 87 votes

answered by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 98 votes

Solving \(L=\frac {3}{2} \sqrt {4 \pi ^2 A^2+W^2}-\frac {\sqrt {5 W \sqrt {4 \pi ^2 A^2+W^2}+6 \pi ^2 A^2+3 W^2}}{\sqrt {2}}+\frac {3 W}{2}\) for \(W\)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=57763

When I solve the aforementioned equation for \(W\) or \(A\) on Mathematica I get a long and ugly equation in return, namely one of the solutions for \(W\) is: (attempt to read at your own health)

asked by J.D’Almbert https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19257 8 votes

answered by Alexei Boulbitch https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=788 15 votes

Entering numbers in Scientific Notation?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=36792

I need to play with a lot of powers such as 10^-3,1E-3 does not work for it. Is there any short form for it?

asked by hhh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2000 59 votes

answered by Joe https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44710 1 vote

Finding unit tangent, normal, and binormal vectors for a given r(t)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18598

For my Calc III class, I need to find \(T(t), N(t)\), and \(B(t)\) for \(t=1, 2\), and \(-1\), given \(r(t)=\{t,t^2,t^3\}\).

I’ve got Mathematica, but I’ve never used it before and I’m not sure how to coerce ...

asked by a98 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5605 30 votes

2.15.3 Can you answer these questions?

   How to force FindClusters to return a specific number of clusters?
   Calculate a nested integral
   Differents Initial Conditions for NDSolve

How to force FindClusters to return a specific number of clusters?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229313

I am using FindClusters with the Method -> "KMedoids" option. I am specifying a desired number of clusters. It returns with many fewer than the desired number. Is there a way to force it ...

asked by abwatson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1709 2 votes

Calculate a nested integral

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229251

I wish to plot the following probability on Mathematica:

       ∫    ∫
         +∞    +∞
π = n ⋅ −∞    −∞

asked by Avocaddo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68764 1 vote

Differents Initial Conditions for NDSolve

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229185

I would like to solve a system of differential equations and another euqtions conect to the system. For example:

asked by Slayz https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74408 1 vote

2.16 Thursday, August 20, 2020

  2.16.1 Top new questions this week
  2.16.2 Greatest hits from previous weeks
  2.16.3 Can you answer these questions?

2.16.1 Top new questions this week

   Deleting duplicates after n-occurrences
   How can I enclose a closed curve with another identical slightly bigger closed curve?
   Glowing weighted graph (network): vertexes and edges
   Why does it take so long to Quit?
   How to use Flatten to a specific element of a list
   Parsing error [bug?] with systems of nonlinear PDEs, Mathematica 12.0.0
   Collecting common powers of terms

Deleting duplicates after n-occurrences

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228775

As a generalization of DeleteDuplicates, I want to delete duplicates from a list, but only after n number of duplicates. Say,

asked by azerbajdzan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53172 11 votes

answered by ciao https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=11467 16 votes

How can I enclose a closed curve with another identical slightly bigger closed curve?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228524

I have a closed curve. I am trying to enclose this closed curve with another closed curve, which looks identical in the shape of the first closed curve, but slightly bigger. How to do this?

asked by acoustics https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53981 10 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 17 votes

Glowing weighted graph (network): vertexes and edges

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228738

I am trying to find a way (desirably simple and performance/speed optimized for larger graphs) to do the following :

Styling graph vertexes by glow-effect and its intensity depending on ...

asked by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 8 votes

answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 5 votes

Why does it take so long to Quit?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228484

Running Quit is a core task repeated many times in any debugging/development cycle. Its efficiency is therefore important and yet in my set-up it is taking ...

asked by Ronald Monson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2249 8 votes

answered by Ronald Monson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2249 9 votes

How to use Flatten to a specific element of a list

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228579

Let's say I have a list {{1, 2, 3}, {4, 5}, ...}. I want to make the list 
look like {1, 2, 3, {4, 5}, ...}. I am doing this way:

asked by Arghya Datta https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=51545 7 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 10 votes

Parsing error [bug?] with systems of nonlinear PDEs, Mathematica 12.0.0

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228692

I find the following behavior using 12.0.0. (EDIT: I asked a friend to try it in 12.1.1 and he finds the same result.) Here is a system of coupled nonlinear PDEs that ...

asked by Will.Mo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=49788 6 votes

Collecting common powers of terms

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228768

How to collect the common powers appearing in the following function using MATHEMATICA, such that if I input

(4 m^6)/((m - n)^2 (m + n)^4 (2m+n)^4)

then the ...

asked by Erosannin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73763 6 votes

answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 3 votes

2.16.2 Greatest hits from previous weeks

   Help find a bright object on Mars!
   How to plot an ellipse?
   How to make the digits of \(\pi \) go around in a spiral like this?
   How to calculate contour integrals with Mathematica?
   How to make a Spherical Cow?
   How to find integer solutions?
   Plotting a Phase Portrait

Help find a bright object on Mars!

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11819

In today’s news, scientists found a bright object on one of Curiosity’s photos (it’s near the bottom of the picture below). It’s a bit tricky to find - I actually spent quite some time staring at the ...

asked by Victor K. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1351 198 votes

answered by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 257 votes

How to plot an ellipse?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=20100

I’m new to Mathematica, and I’m finding it difficult to plot an ellipse. I tried using

Plot[(x/5)^2 + (y/3)^2 == 1, {x, -5, 5}, {y, -3, 3}]

but I’m getting ...

asked by Sriram https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6075 17 votes

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 29 votes

How to make the digits of \(\pi \) go around in a spiral like this?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=109982

Here is a start.

MapIndexed[Text[Reverse[First[RealDigits[Pi,10,252]]][[Tr@#2]],#]&, 
 Table[{t Cos[t],t Sin[t]},{t,0,16Pi,0.2}]]//Graphics

asked by matrix89 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5379 56 votes

answered by Martin Ender https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2305 71 votes

How to calculate contour integrals with Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=34073

How to calculate the integral of \(\frac {1}{\sqrt {4 z^2 + 4 z + 3}}\) over the unit circle counterclockwise for each branch of the integrand?

asked by user64494 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7152 40 votes

answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 63 votes

How to make a Spherical Cow?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=125043

Being a theoretical physicist, I always have a great respect for Spherical Cow. So I thought about making one myself. I am not sure how can I create (something considered to be the simplest!) this ...

asked by Sumit https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8070 69 votes

answered by andre314 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5467 76 votes

How to find integer solutions?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=42359

Following is the equation: Need to solve for integer values of x,y when a,b lies between -1000 and 1000. Problem is to find the number of integer values of pair (x,y) that satisfy it.

asked by Sahil Sareen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12396 2 votes

answered by bill s https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1783 4 votes

Plotting a Phase Portrait

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=14160

I’m trying to plot a phase portrait for the differential equation

 ′′        2  ′
x −  (1 − x )x + x = 0.5cos(1.1t).

The primes are derivatives with respect to \(t\). I’ve reduced this second order ODE to ...

asked by covertbob https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4528 38 votes

answered by David Slater https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1746 32 votes

2.16.3 Can you answer these questions?

   Export function not working via JLink in Java8 compiled application
   Custom arrowhead will not align properly
   How to control a presenter notebook with a mobile device?

Export function not working via JLink in Java8 compiled application

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228496

I have documented the following issue with evaluating the Export function via J/Link: https://stackoverflow.com/questions/63390977/wolfram-mathematica-kernellink-export-function-not-working-via-jlink- ...

asked by Ceddaerrix https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74211 1 vote

Custom arrowhead will not align properly

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228631

I am trying to put a custom arrowhead on an arrow I am drawing in a plot. My problem is that the (thick) line of the arrow is showing behind the arrow tip. So it seems like the arrowhead is aligned ...

asked by Bjoj https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36437 1 vote

How to control a presenter notebook with a mobile device?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228733

In the video of the link below, at 1:40 is said that the presentation can be controlled by a mobile device, how can I do that?

https://www.youtube.com/watch?v=GMHM_iUL_sU

asked by Daniel Rocha da Silva https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74279 1 vote

2.17 Thursday, August 13, 2020

  2.17.1 Top new questions this week
  2.17.2 Greatest hits from previous weeks
  2.17.3 Can you answer these questions?

2.17.1 Top new questions this week

   Which function names have been re-purposed in Mathematica after being deprecated?
   StringJoin in Thread not working
   Using sequence to complete arguments to a function
   How can I get the progressive application of list of rules?
   Finding the Period of a Limit Cycle
   Assigning a Color to each Point on the Plane
   using regex to find a specific word

Which function names have been re-purposed in Mathematica after being deprecated?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228295

I have just learned about the new function Splice from this answer. It turns out that this function used to have a completely different usage! (See below.) To me, this seems dangerous, to deprecate a ...

asked by march https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29734 14 votes

answered by J. M.’s technical difficulties https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 9 votes

StringJoin in Thread not working

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228320

Here is what I have tried first.

Thread[f["x", {"1", "2"}]] 
 
{f["x", "1"], f["x", "2"]}

But the weirdest thing happened when I ...

asked by kile https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=65814 7 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 9 votes

Using sequence to complete arguments to a function

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228363

I have a function of, say 4 arguments f[a,b,{c,e},d] where some of the arguments are lists. Given a list of triplets that are possible last-three-arguments to f I’d like to paste them as arguments to ...

asked by ulvi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1714 6 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes

How can I get the progressive application of list of rules?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228088

I have a very long list of rules, and using this list of rules I want to see how some elements evolve as I successively apply the next rules on the previous rule.

Here is the simpler version of my ...

asked by Gummala Navneeth https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66938 6 votes

answered by march https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29734 9 votes

Finding the Period of a Limit Cycle

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228319

I’m interested in the periods of limit cycles of the Wilson-Cowan equations which have the form

 ′
x(t) = − x + S(ax(t)− by(t)+ e)

 ′
y(t) = − y + S(cx(t)− dy(t)+ f)

where

S(x) = 1+

...

asked by Cheyne https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74162 5 votes

answered by Chris K https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6358 6 votes

Assigning a Color to each Point on the Plane

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228423

I have a dataset consisting of points on the plane and a corresponding color. These colors divide the plane into a few distinct regions. I would like to make a plot or diagram that nicely shows this ...

asked by Cheyne https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74162 5 votes

answered by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 4 votes

using regex to find a specific word

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228278

I want to find the word ”circle” and ”circles” in the list.

list = {"circle" , "picircle" , "circles" }

The regex code I wrote which isn’t working:

asked by Aryan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73776 5 votes

answered by Natas https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=67431 7 votes

2.17.2 Greatest hits from previous weeks

   Can Mathematica do symbolic linear algebra?
   How to make the digits of π go around in a spiral like this?
   How to plot an ellipse?
   Standard deck of 52 playing cards in curated data?
   Skip header lines on import
   How to graph a sphere with cartesian equations?
   How to create a new ”person curve”?

Can Mathematica do symbolic linear algebra?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3242

For instance, is there some way I can say ”let A and B be arbitrary real \(m\times n\) and \(k\times m\) matrices, Simplify[Transpose[Transpose[A].Transpose[B]]]” and Mathematica would simplify it to B.A? ...

asked by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 63 votes

answered by Chip Hurst https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4346 6 votes

How to make the digits of π go around in a spiral like this?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=109982

Here is a start.

MapIndexed[Text[Reverse[First[RealDigits[Pi,10,252]]][[Tr@#2]],#]&, 
 Table[{t Cos[t],t Sin[t]},{t,0,16Pi,0.2}]]//Graphics

asked by matrix89 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5379 56 votes

answered by Martin Ender https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2305 71 votes

How to plot an ellipse?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=20100

I’m new to Mathematica, and I’m finding it difficult to plot an ellipse. I tried using

Plot[(x/5)^2 + (y/3)^2 == 1, {x, -5, 5}, {y, -3, 3}]

but I’m getting some errors. Is there something wrong ...

asked by Sriram https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6075 17 votes

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 29 votes

Standard deck of 52 playing cards in curated data?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16108

I am not sure how to find out what all is included as curated data. For example, are the individual images of each of the 52 cards in a standard deck of playing cards included?

If not, is there a way ...

asked by JohnD https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1629 25 votes

answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 23 votes

Skip header lines on import

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=50718

When importing a data file what are the comment symbols for Mathematica? That is, given a file like this

blabla 
bulbul 
 
1 2 6 54 7 ... 
..

what symbol do I have to put in front of header lines so ...

asked by MaxJ https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=14687 20 votes

answered by george2079 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2079 18 votes

How to graph a sphere with cartesian equations?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=24169

I’m new to Mathematica and I need to ask how to graph a sphere, cylinder, etc.. using cartesian equations.

For example in sphere’s case \(x^2+y^2+z^2=1\)

I tried to use Plot3D but it doesn’t ...

asked by German https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7145 7 votes

answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 13 votes

How to create a new ”person curve”?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=17704

Wolfram—Alpha has a whole collection of parametric curves that create images of famous people. To see them, enter WolframAlpha["person curve"] into a Mathematica notebook, or person curve into ...

asked by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 83 votes

answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 45 votes

2.17.3 Can you answer these questions?

   Mathematica 12.0 and BibTeX reference problem (Windows 10)
   How to convince Mathematica that \((-1)^{2/3} = e^{2\pi i /3}\)
   How to monitor progress of multiple downloads with URLDownload?

Mathematica 12.0 and BibTeX reference problem (Windows 10)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228347

I have problems getting the Citation Management in Mathematica 12.0 to work. It does not work with either EndNote or BibTeX. To do a minimal example, I have the following BibTeX file (libra.bib) ...

asked by jaclea https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7911 1 vote

How to convince Mathematica that \((-1)^{2/3} = e^{2\pi i /3}\)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228257

I have a list T which contains 3 + 4*E^(2*Pi*I/3). Yet MemberQ[ T , 3 + 4*(-1)^(2/3) ] 
returns false. 
One can check for themselves with MemberQ[{3 + 4*E^(2*Pi*I/3)}, 3 + 4*(-1)^(2/3)]. 
It will return  ...

asked by Descartes Before the Horse https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69355 2 votes

How to monitor progress of multiple downloads with URLDownload?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228403

I have a few image urls that I want to download async, how can we monitor progress of URLDownload? Example:

Monitor[ 
    URLDownload[ 
         WebImageSearch["dog",  ...

asked by M.R. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=403 1 vote

2.18 Thursday, August 6, 2020

  2.18.1 Top new questions this week
  2.18.2 Greatest hits from previous weeks
  2.18.3 Can you answer these questions?

2.18.1 Top new questions this week

   How can I find a functional square root in Mathematica?
   The numerics of FresnelS[]
   How to enter a nuclear reaction?
   How to find a numerical antiderivative with NIntegrate methods?
   How to draw one-line Venn diagram?
   How to express permutation as the least number of exchanges
   Remove mesh triangles in contour plot

How can I find a functional square root in Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=227863

A functional square root of a function \(g\) is another function \(f\) such that \(g=f\circ f\). According to that article, there is a systematic approach to finding a functional square root that involves ...

asked by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 10 votes

answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 2 votes

The numerics of FresnelS[]

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=227893

Bug introduced in 12.1 or earlier and persisting through 12.1.1 or later [CASE:4615361]

Note: A worse problem existed in 12.0 for inputs greater than 8 and of precisions less than 43.66; 12.1 fixed ...

asked by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 9 votes

answered by J. M.’s technical difficulties https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 6 votes

How to enter a nuclear reaction?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=227846

Sometimes the simplest things are the most difficult, I need to make a presentation, and I thought to do it in Mathematica, I wanted to do a demonstration too, well...this is the Rutherford’s equation

asked by Chris Schwenke https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=65367 9 votes

answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 14 votes

How to find a numerical antiderivative with NIntegrate methods?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=227869

@JimBelk asked in Interpolating an Antiderivative how to find a numerical antiderivative. I gave an answer that uses NDSolve with the default method for integrating \(y'=f(x,y)\). However for ...

asked by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 8 votes

answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 9 votes

How to draw one-line Venn diagram?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=227990

This is the a list of set.

data = {{"A"}, {"J"}, {"Q"}, {"G", "H"}, {"I", "O"}, 
  {"B", "C", "E",  ...

asked by partida https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=15961 6 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 10 votes

How to express permutation as the least number of exchanges

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=227996

If there are grammatical or terminological errors in the following description, please help correct:

In some problems, it is necessary to find out what minimum number of exchanges can change a list ...

asked by Ordinary users68 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42417 5 votes

answered by Hausdorff https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73380 5 votes

Remove mesh triangles in contour plot

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=227837

How do I get rid of the mesh in this contour plot?

 ContourPlot[x^2 + y^2, {x, -10, 10}, {y, -10, 10}, 
    Contours -> {1.0, 4.0, 10.5}, ContourStyle -> None, 
    ContourShading ->  ...

asked by QuantumDot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2048 5 votes

answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 6 votes

2.18.2 Greatest hits from previous weeks

   How to create animated snowfall?
   What does # mean in Mathematica?
   Elegant operations on matrix rows and columns
   Help find a bright object on Mars!
   Plot, extract data to a file
   Labeling individual curves in Mathematica
   How to add a vertical line to a plot

How to create animated snowfall?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16881

Well, the title is self-explanatory. What sorts of snowfall can we generate using Mathematica? There are two options I suggest to consider:

1) Continuous GIF animations with smallest possible number ...

asked by faleichik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=219 39 votes

answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 53 votes

What does # mean in Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19035

I asked Mathematica to compute the following

Solve[c (1-x)^2-x^(1/4) == 0, x] 
 
and it returned this: 
 
  x = Root[#1^8 c^4 - 8 #1^7 c^4 + 28 #1^6 c^4 - 56 #1^5 c^4 + 70 #1^4 c^4 - 56 #1^3 c^4 + 28  ...

asked by ronanymous https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5730 37 votes

answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 63 votes

Elegant operations on matrix rows and columns

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3069

Question

The Mathematica tutorial has a section ’Basic Matrix Operations’, describing operations like transpose, inverse and determinant. These operations all work on entire matrices. I am missing a ...

asked by sjdh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=515 179 votes

answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 60 votes

Help find a bright object on Mars!

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11819

In today’s news, scientists found a bright object on one of Curiosity’s photos (it’s near the bottom of the picture below). It’s a bit tricky to find - I actually spent quite some time staring at the ...

asked by Victor K. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1351 198 votes answered by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 257 votes

Plot, extract data to a file

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19859

I need to save data that Mathematica uses inside the Plot command. The format that I would like to have is:

x1 y1 
x2 y2

i.e. basically, two columns, x and y (sorted, if possible) so that I ...

asked by molkee https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5097 29 votes

answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 46 votes

Labeling individual curves in Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=4444

I need to create a plot for export and inclusion in a report. Is there a better way to label curves than PlotLegends? From what I’ve read and my personal experience, PlotLegends is pretty bad.

Is ...

asked by Tianxiang Xiong https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1041 62 votes

answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 46 votes

How to add a vertical line to a plot

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3561

In the plot below I would like to add two vertical lines at \(x = \frac {\pi }{15} \pm \frac {1}{20}\). How can I do that?

f[x_] := (x^2 z)/((x^2 - y^2)^2 + 4 q^2 x^2) /. {y -> π/15, z -> 1, q ->  ...

asked by sjdh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=515 56 votes

answered by Ajasja https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=745 76 votes

2.18.3 Can you answer these questions?

   Does MMA have a built-in function or a user-defined function to judge whether the two matrices are congruent
   Symbolic solution to periodic boundary conditions
   Collecting terms in NCAlgebra

Does MMA have a built-in function or a user-defined function to judge whether the two matrices are congruent

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=227756

It can be seen from the following relationship that matrix A and matrix B must be congruent matrices with each other:

A = {{1, 4, 4}, {5, 2, 2}, {3, 1, 3}}; 
B = EulerMatrix[{π/4, 0,  ...

asked by Ordinary users68 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42417 3 votes

Symbolic solution to periodic boundary conditions

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228028

Is it possible to get an analytical solution to the following problem? If so, how?

   (1,0)          (0,1)
aw    (x,t)+ bw    (x,t) = p(x) + gw(x,t)

asked by Scott G https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74062 1 vote

answered by Michael Seifert https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27813 0 votes

Collecting terms in NCAlgebra

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=227812

Let's say we have GP[v],GM[v]: two noncommutative objects depending on the commutative variable v. 
<< NC`; 
<< NCAlgebra`; 
SetCommutative[v]; 
SetNonCommutative[GP, GM] 
NCCollect[ 
 GM[v] **  ...

asked by Kawette https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=60529 1 vote

2.19 Thursday, July 23, 2020

  2.19.1 Top new questions this week
  2.19.2 Greatest hits from previous weeks
  2.19.3 Can you answer these questions?

2.19.1 Top new questions this week

   How to rewrite a tensor as a matrix
   Breaking ”Functional Loops” and Doing Lazy Evaluation In Mathematica
   Hexadecimal bytes as variable converted to binary bits
   Kernel starts up very slowly on Linux
   How to decompose a list of n-tuples into a union of Cartesian products
   Mathematica emits a beep after any evaluation - how to remove it?
   Prony series with a large number of terms

How to rewrite a tensor as a matrix

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=226089 I put

{TensorProduct[{1, 0}, {0, 1}, {0, 1}, {0, 1}, {0, 1}]}/Sqrt[2]//MatrixForm 
and I got 
$$ 
\left( 
\begin{array}{cc} 
 \left( 
\begin{array}{cc} 
 \left( 
\begin{array}{cc} 
 0 & 0 \\ 
 0 & 0 \\

asked by Moeki https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73815 12 votes

answered by Suba Thomas https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5998 9 votes

Breaking ”Functional Loops” and Doing Lazy Evaluation In Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=226334

Alright, so this is a question about the functional way to break a for/while loop. Since we’re on the Mathematica SE, I’m interested in the ways a Mathematica vet would handle this, however the ...

asked by dskeletov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34831 8 votes

answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 6 votes

Hexadecimal bytes as variable converted to binary bits

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=226171

I am working with hexadecimal bytes but need to shift them into lists of binary bits for a few operations and then back again. For example, I would like C12B to turn into ...

asked by toothandsticks https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73837 8 votes

answered by Hausdorff https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73380 9 votes

Kernel starts up very slowly on Linux

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=226128

V 12.1.1, starting a kernel, e.g. by entering wolframscript in the shell, takes 
an unexpectedly long time (~5 min, the time elapsed between pressing Enter and 
the showing-up of In[1] := ); but the  ...

asked by Αλέξανδρος Ζεγγ https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12924 8 votes

answered by Ordinary users68 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42417 5 votes

How to decompose a list of n-tuples into a union of Cartesian products

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=226294

I have a list with all elements at the same level

{ 
    {a, d}, {a, e}, {a, f}, 
    {b, d}, {b, e}, {b, f}, 
    {c, d}, {c, e}, {c, f}, 
    {x, t}, {x, q} 
}

How can I transform this to a list of ...

asked by Martin Leung https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73880 7 votes

answered by yarchik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9469 4 votes

Mathematica emits a beep after any evaluation - how to remove it?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=226316

Without any obvious reason Mathematica started to emit a beep after each evaluation, even when it is error free. Why is that, and how can I turn it off? I tried restarting Mathematica to no avail, and ...

asked by Jxx https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68480 6 votes

answered by Ordinary users68 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42417 6 votes

Prony series with a large number of terms

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=226327

A Prony series is similar to a Fourier series but can have fewer terms. It takes the form \(\sum _{i=1}^{M} A_i e^{\sigma _i t} \cos \left (\omega _i t+\phi _i\right )\) Note that unlike Fourier series ...

asked by Hugh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12558 6 votes

2.19.2 Greatest hits from previous weeks

   Is there an open source implementation of Mathematica-the-language?
   Image processing: Floor plan - detecting rooms’ borders (area) and room names’ texts
   How to make Jacobian automatically in Mathematica
   Skip header lines on import
   How to find the position of elements in a list satisfying criteria
   How to make an inkblot?
   How to generate a random snowflake

Is there an open source implementation of Mathematica-the-language?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=4454

I’ve seen questions before such as ”What is the best open-source equivalent for Mathematica?”, but that specific question (and that line of inquiry in general) cares more about the computer algebra ...

asked by sblom https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=178 121 votes

answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 83 votes

Image processing: Floor plan - detecting rooms’ borders (area) and room names’ texts

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19546

Here is a simple building floor plan. I would like to derive the rooms as (rectangular) components and the names of the rooms. This is very common representation of building floor plans.

The ...

asked by s.s.o https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=840 63 votes

answered by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 58 votes

How to make Jacobian automatically in Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=5790

If we have two vectors, \(a\) and \(b\), how can I make Jacobian matrix automatically in Mathematica?

$$ a=\left( 
\begin{array}{c} 
 x_1^3+2x_2^2 \\ 
 3x_1^4+7x_2 
\end{array} 
\right);b=\left(

asked by George Mills https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1012 38 votes

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 50 votes

Skip header lines on import

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=50718

When importing a data file what are the comment symbols for Mathematica? That is, given a file like this

blabla bulbul

1 2 6 54 7 ...

what symbol do I have to put in front of header lines so ...

asked by MaxJ https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=14687 20 votes

answered by george2079 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2079 18 votes

How to find the position of elements in a list satisfying criteria

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=180

Say I have a list x=2,4,6,8,10 and I want to find out the positions of the elements that are greater than 7.

Select[x, #>7&] gives the elements themselves, and Position[x,8] gives the  ...

asked by PeterR https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=140 65 votes

answered by J. M.’s technical difficulties https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 62 votes

How to make an inkblot?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3345

How to effectively create a polygon that looks like a realistic inkblot? So far, I could come up with this (borrowing from Ed Pegg Jr.’s Rorschach demonstration):

RandomBlot[num_, opts___] :=  ...

asked by István Zachar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 86 votes

answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 51 votes

How to generate a random snowflake

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=39361

’Tis the season... And it’s about time I posed my first question on Mathematica Stack Exchange. So, here’s an holiday quest for you Graphics (and P-Chem?) gurus.

What is your best code for generating ...

asked by Peltio https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6745 140 votes

answered by Silvia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=17 181 votes

2.19.3 Can you answer these questions?

   How to write this piece of code without AppendTo
   Solving a cubic equation in mathematica
   Using Select for lattice points

How to write this piece of code without AppendTo

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=226081

I am trying to fill a vector starting from component 11 from another vector, I use this code:

Do[AppendTo[xp, x[[i + 10]]], {i, 1, 99982}]

How can I fill xp without using ‘AppendTo’?

asked by mattiav27 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8822 1 vote

Solving a cubic equation in mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=226231

I am trying to solve a cubic equation using Mathematica of a rather complicated expression say \(f(r,\beta ,\theta )\) , and in terms of \(r\) the maximum degree term that appears is of degree \(3\) so I ...

asked by Wubba lubba dub dub https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70072 1 vote

Using Select for lattice points

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=226130

I know how to use Select to generate a list of numbers which satisfy a certain condition. However, I am not sure how to do this for points (specifically 2-tuples) rather than numbers. What I am trying ...

asked by Descartes Before the Horse https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69355 1 vote

2.20 Thursday, July 16, 2020

  2.20.1 Top new questions this week
  2.20.2 Greatest hits from previous weeks
  2.20.3 Can you answer these questions?

2.20.1 Top new questions this week

   Reveal the formal PDE of FiniteElement
   Drag and lift force acting on an airfoil
   When is a symbol a Symbol? Is there an easy mathematica way to test if an object is a symbol sort of like a SymbolQ?
   Using Regular Expression
   Changing the color of the animate box
   Bad linear fit for simple data
   How to use each replacement only once in a list of replacements

Reveal the formal PDE of FiniteElement

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225711

When FiniteElement method is used, the differential equations will first be transformed to certain standard form (named as formal PDE in recent FEM document), and it turns out to be critical to check ...

asked by xzczd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1871 11 votes

answered by user21 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18437 8 votes

Drag and lift force acting on an airfoil

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225928

To calculate force acting on an airfoil we can use FEM with version 12 and over. Here we show an example with NACA2415. First we calculate mesh and potential flow:

ClearAll[NACA2415]; 
NACA2415[{m_,  ...

asked by Alex Trounev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58388 9 votes

answered by user21 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18437 6 votes

When is a symbol a Symbol? Is there an easy mathematica way to test if an object is a symbol sort of like a SymbolQ?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225811

Yes I know there is no built in native function called SymbolQ (but JavaScript does). However could one be simulated to work for most cases? I often rely

on objectName[symbol] and makeRuleRow[symbol]  ...

asked by Jules Manson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=37721 9 votes

answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 8 votes

Using Regular Expression

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225910

sample2 = ”this is a test to find whether pi works for other words or not as well pi pi pi potatpi pineapple pi-neapple”;

so sample2 is a string, and I want to search the word/substring ...

asked by Aryan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73776 8 votes

answered by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 9 votes

Changing the color of the animate box

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225941

Is there a way to change the coloring of the boxes that are generated by Animate or Manipulate? The color of what is gray by default.

Animate[ArrayPlot[CellularAutomaton[n, {{1}, 0}, {40, All}]], {n,  ...

asked by thinkingdude https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73139 8 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 9 votes

Bad linear fit for simple data

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225985

I have some data :

data={{1.01074, 0.964488}, {1.08552, 0.993067}, {1.07907, 
  1.01836}, {1.0477, 1.03695}, {1.07717, 1.07973}, {1.10243, 
  1.08195}, {1.12669, 1.09112}, {1.09405, 1.09319},  ...

asked by J.A https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58104 7 votes

answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 12 votes

How to use each replacement only once in a list of replacements

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225929

I have a list of replacements and some list they are acting on. However, some RHS of the replacements rules are identical (the LHS is not). I want to use those rules one after another (perhaps cycling ...

asked by Kvothe https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45020 7 votes

answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 5 votes

2.20.2 Greatest hits from previous weeks

   Positioning axes labels
   Generate a Unit Circle Trigonometry
   Is there something like DensityPlot3D to visualize atomic orbitals?
   Mathematica command that allows it to read my intentions
   Does Mathematica 11 work with MacOS Catalina 10.15
   Finding Limits in several variables
   Parallel and perpendicular symbol from Mathematica to LaTeX

Positioning axes labels

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=87388

I need to change the position of my axes labels such that the y-axis label is in the middle and parallel to the y-axis. I’d also like the x-axis label to be in the middle of the x-axis rather than ...

asked by John_dydx https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7849 15 votes

answered by Virgil https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27697 16 votes

Generate a Unit Circle Trigonometry

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2456

Struggling often with Trigonometry I would like to have some code to generate this Unit Circle Trigonometry. Would be of great help when I need to transform some data :

asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 18 votes

answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 32 votes

Is there something like DensityPlot3D to visualize atomic orbitals?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=32378

I’m visualizing some hydrogen like atomic orbitals. For looking at plane slices of the probability density, the DensityPlot function works well, and with something like:

Manipulate[ 
 DensityPlot[  ...

asked by Peeter Joot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10 45 votes

answered by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 24 votes

Mathematica command that allows it to read my intentions

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=194384

In version 2.0 of Mathematica there was a command, ReadProgrammerIntentions[ ] which allowed it rapidly compose code that could solve problems simple to complex, based on my requirements. Understand ...

asked by MikeY https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=47314 52 votes

answered by MarcoB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27951 38 votes

Does Mathematica 11 work with MacOS Catalina 10.15

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=207522

I just upgraded my macbook to 10.15 and could not open Mathematica 11. I am wondering are there any workarounds to use Mathematica 11 without upgrading to 12? Thank you!

asked by Jiang Xiang https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=16218 27 votes

answered by Itai Seggev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4848 18 votes

Finding Limits in several variables

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=21544

Is there a way to find a limit of a multivariable function, like

(x,yl)im→ (0,0)f(x,y)

with Mathematica?

When \(f\) is continuous, we can use

  lim
(x,y)→ (0,0)

...

asked by Dominic Michaelis https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5899 31 votes

answered by whuber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=91 42 votes

Parallel and perpendicular symbol from Mathematica to LaTeX

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=46538

I want to get the following expression from Mathematica to LaTeX:

\begin{bmatrix} 
E_{\parallel} \\ E_{\perp} 
\end{bmatrix}

I have tried to use inbuilt ’symbol’ character from the special ...

asked by Steve Hatcher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13314 18 votes

answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 26 votes

2.20.3 Can you answer these questions?

   Finding the domain in which a function is analytic with no imaginary part
   Argmax - all maximizer positions
   AceFEM MacOS not responding

Finding the domain in which a function is analytic with no imaginary part

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225913

I was wondering if it is easy to see if a given expression evaluates to a real number in a given domain? Let e.g. \(f(x,y,z)\) be some function depending on three variables \(x,y,z\). I would like to know if ...

asked by CAF https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=30885 1 vote

Argmax - all maximizer positions

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225980

Generally the Argmax function returns one position, where a function is maximized. Is there a easy way to obtain a list of rules for all maximizer points?

asked by Daniel Rehsmann https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73792 1 vote

answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 0 votes

AceFEM MacOS not responding

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225678

I just upgraded to v7.114 of AceFEM running on MacOS 10.15.5 and Mathematica 12.0.0.0. I was running v7.101 without a problem. AceGEN seems to work but all AceFEM code starts but does nothing. The ...

asked by Andrew https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73727 1 vote

2.21 Thursday, July 9, 2020

  2.21.1 Top new questions this week
  2.21.2 Greatest hits from previous weeks
  2.21.3 Can you answer these questions?

2.21.1 Top new questions this week

   How to solve the Monty Hall problem?
   Change Opacity along a ListLinePlot
   Use Cases with empty cells in the list
   Writing compiled functions as fast as Python’s Numba
   Why are more highly nested lists often not more memory and time-intensive?
   Correcting the Color Scale of a MatrixPlot
   Verify an inequality of many parameters

How to solve the Monty Hall problem?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225238

Problem For purely recreational purposes I would like to solve the Monty Hall problem with Mathematica using the function Probability (dedicated to the calculation of probabilities). About the Monty ...

asked by mlpo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=11155 12 votes

answered by Sjoerd Smit https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=43522 16 votes

Change Opacity along a ListLinePlot

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225337

I’m trying to change the opacity of a line in a ListLinePlot for increasing x-value. E.g. the line should have opacity 1 at beginning and shade than down to opacity along the line. I want to take the ...

asked by piolio https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73660 10 votes

answered by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 8 votes

Use Cases with empty cells in the list

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225360

I work with a complex dataset. The most simple form of this list looks like:

dat1 = {{a, b, c, {}}, {d, e, f, {1}}, {h, i, j, {2}}} 
 
I want to select the nested {} part. 
Cases[dat1, {___, {a_}} :>  ...

asked by Michiel van Mens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9590 9 votes

answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 9 votes

Writing compiled functions as fast as Python’s Numba

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225277

I want to write some code to simulate a damped oscillator that is just as fast as code written using Numba's @njit decorator. I’ve written the mathematica code and mine is 20-40x slower than the ...

asked by Diffycue https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46327 9 votes

answered by xzczd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1871 16 votes

Why are more highly nested lists often not more memory and time-intensive?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225540

I would expect more highly nested lists, being deeper and more complex than flatter lists, to take up more space (bytecount) and take more time and memory to operate on in general. Consider the ...

asked by Just Some Old Man https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12697 7 votes

answered by Henrik Schumacher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=38178 10 votes

Correcting the Color Scale of a MatrixPlot

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225186

I did a MatrixPlot of a set of values that range between 0 and 1. I got the following first plot with no problems:

As we can see from the legend, the values range between 0 and 1. Now, I am doing ...

asked by Naps https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73570 7 votes

answered by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 5 votes

Verify an inequality of many parameters

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225380

I’ve got an inequality of 10 non-negative parameters (arising from a 5x5 matrix) and would like to verify whether it holds. I tried the following, which doesn’t seem to work:

asked by Vicky https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73675 6 votes

answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 4 votes

2.21.2 Greatest hits from previous weeks

   How to calculate scalar curvature Ricci tensor and Christoffel symbols in Mathematica?
   Figuring when the minute and hour hand coincide on a clock
   xkcd-style Plots
   Are you interested in purchasing David Wagner’s ”Power programming with Mathematica”?
   Parallel and perpendicular symbol from Mathematica to LaTeX
   Mathematica Minecraft
   Labeling individual curves in Mathematica

How to calculate scalar curvature Ricci tensor and Christoffel symbols in Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8895

I am seeking a convenient and effective way to calculate such geometric quantities. I’ve used packages like TensoriaCalc, but they don’t work at all time. Sometimes, I run into the following error:

asked by Zoe Rowa https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1713 38 votes

answered by Yi-Zen Chu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4869 18 votes

Figuring when the minute and hour hand coincide on a clock

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=573

I would like to list all possible times in a 12-hour period, where the hour hand overlaps the minute hand completely. This is really a question about three distinct things - to be done in Mathematica ...

asked by Steve D https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=191 15 votes

answered by Verbeia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8 21 votes

xkcd-style Plots

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11350

I received an email to which I wanted to respond with a xkcd-style graph, but I couldn’t manage it. Everything I drew looked perfect, and I don’t have enough command over PlotLegends to have these ...

asked by Amatya https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2039 613 votes

answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 472 votes

Are you interested in purchasing David Wagner’s ”Power programming with Mathematica”?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16485

I recently contacted McGraw-Hill to see if they have a mechanism in place for printing out-of-print books that are still of interest. Specifically, I asked about ”Power programming with Mathematica” ...

asked by Todd Allen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=249 158 votes

answered by Todd Allen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=249 233 votes

Parallel and perpendicular symbol from Mathematica to LaTeX

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=46538

I want to get the following expression from Mathematica to LaTeX:

 
\begin{bmatrix} 
E_{\parallel} \\ E_{\perp} 
\end{bmatrix}

I have tried to use inbuilt ’symbol’ character from the special ...

asked by Steve Hatcher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13314 18 votes

answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 26 votes

Mathematica Minecraft

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19669

Some time ago I asked myself: with all these great graphics and interactive capabilities of Mathematica, what kinds of 3D games can be implemented in it? And the answer which came to mind is ...

asked by faleichik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=219 164 votes

answered by faleichik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=219 234 votes

Labeling individual curves in Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=4444

I need to create a plot for export and inclusion in a report. Is there a better way to label curves than PlotLegends? From what I’ve read and my personal experience, PlotLegends is pretty bad.

asked by Tianxiang Xiong https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1041 62 votes

answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 46 votes

2.21.3 Can you answer these questions?

   How to include a meter in Manipulate that shows a value calculated from the manipulate dynamic variable?
   Measuring the time remaining until completion for built in functions
   creating uppertriangularized matrix

How to include a meter in Manipulate that shows a value calculated from the manipulate dynamic variable?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225465

I’m trying to make a visualization of grid (representing magnetic states) and I want to include a meter that shows a variable calculated from the manipulate index

(of the form J1/J2 = (index)*0.1) so  ...

asked by mike1994 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73104 1 vote

Measuring the time remaining until completion for built in functions

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225436

All of the functions in How to create a progress bar?, the ProgressIndicator built-in and Monitoring lengthy computations estimate the completion time for implementation of operations that are ...

asked by thinkingdude https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73139 1 vote

creating uppertriangularized matrix

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225231

I am trying to create an uppertriangularized matrix of arbitrary size,max of the form

{{1,2,3,4,5},{0,1,2,3,4},{0,0,1,2,3},{0,0,0,1,2},{0,0,0,0,1}} 
 
using the code 
table = Table[mu^(j - 1)  ...

asked by Z Ming Ma https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70345 1 vote

2.22 Thursday, July 2, 2020

  2.22.1 Top new questions this week
  2.22.2 Greatest hits from previous weeks
  2.22.3 Can you answer these questions?

2.22.1 Top new questions this week

   How to make a structured mesh with a hole and extrude it
   How to NOT a specific pattern?
   Ordering Problem With VoronoiMesh
   Peculiar behaviour in the implementation of ”Filling”
   i_:0—1 varies in v12.1: incompatible change or bug?
   Inverse of StringReplace
   Intersection of 3 circles in GeometricScene

How to make a structured mesh with a hole and extrude it

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224739

I am trying to use the FEMAddOns package to make a structured mesh with a hole and then extrude it. As a warm up example this worked nicely.

Needs["FEMAddOns`"] 
pts1 = Table[ 
  25. (  ...

asked by Hugh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12558 14 votes

answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 13 votes

How to NOT a specific pattern?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225008

been going around in cirlces on this:

{1/3, 1, 0.22, 3, "v", 4} /. _?NumericQ -> "999"

Now I’m trying to replace everything that is not a number; is there a way to do this? ...

asked by CuriousDudeFromEgypt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66462 10 votes

answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 13 votes

Ordering Problem With VoronoiMesh

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224830

Imagine I want to model 2D cells moving in a tissue. Consider, as an example, Lloyd’s relaxation algorithm. Using VoronoiMesh I’m able to mimic some cell movement. Now, if I colour one of the cells in ...

asked by sam wolfe https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=64001 9 votes

answered by TumbiSapichu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53229 2 votes

Peculiar behaviour in the implementation of ”Filling”

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224907

I was working with mathematica and I need to use ”Filling”, however I notice that it doesn’t work when you have ”small” numbers, for example if I make the following:

asked by Cruz https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69573 9 votes

i_:0—1 varies in v12.1: incompatible change or bug?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224987

Just check

i_: 0 | 1 // FullForm 
 
In v12.0 or earlier the output is 
Alternatives[Optional[Pattern[i, Blank[]], 0], 1] 
 
But in v12.1 the output becomes 
Optional[Pattern[i, Blank[]], Alternatives[0,  ...

asked by xzczd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1871 9 votes

answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 9 votes

Inverse of StringReplace

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225071

Suppose I have the following StringReplace rule

StringReplace[st, {"a" -> "0", "OverBar[a]" -> "1", "b" -> "1",

asked by math https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72358 8 votes

answered by Suba Thomas https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5998 8 votes

Intersection of 3 circles in GeometricScene

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224874

I am trying to represent the image below in Mathematica and can’t seem to make it work. There doesn’t seem to be any constraint of type circle intersection in the documentation. I tried this:

asked by SorinS https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73427 8 votes

answered by SneezeFor16Min https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69875 11 votes

2.22.2 Greatest hits from previous weeks

   Why I get the ”Set::write: ”Tag Times in is Protected.” error?
   What are the most common pitfalls awaiting new users?
   Is it possible to export the equations from Mathematica to MATLAB?
   Generate a Unit Circle Trigonometry
   How to find the position of elements in a list satisfying criteria
   Get a ”step-by-step” evaluation in Mathematica
   Is there any algorithm that runs faster in Mathematica than in C or Fortran?

Why I get the ”Set::write: ”Tag Times in is Protected.” error?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11868

Why I get the error below with this code:

Needs["VectorAnalysis`"] 
 
ρ = 1000; 
g = 9.80665; 
μ = 0.001; 
p[x_, y_, z_, t_] = {x^2, Sqrt[y], -z, t^3}; 
f[x_, y_, z_, t_] = {-x^2, Sqrt[y]/2, z, t^2}; 
 
ρ  ...

asked by Aurelius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1669 10 votes

answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 13 votes

What are the most common pitfalls awaiting new users?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18393

As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...

asked by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 462 votes

answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 279 votes

Is it possible to export the equations from Mathematica to MATLAB?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=14035

Is it possible to export the output expressions from Mathematica computations (e.g., equations) in valid MATLAB syntax?

asked by Seyhmus Güngören https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4256 41 votes

answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 48 votes

Generate a Unit Circle Trigonometry

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2456

Struggling often with Trigonometry I would like to have some code to generate this Unit Circle Trigonometry. Would be of great help when I need to transform some data :

asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 18 votes

answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 32 votes

How to find the position of elements in a list satisfying criteria

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=180

Say I have a list x=2,4,6,8,10 and I want to find out the positions of the elements that are greater than 7.

Select[x, #>7&] gives the elements themselves, and Position[x,8] gives the  ...

asked by PeterR https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=140 64 votes

answered by J. M.’s technical difficulties https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 62 votes

Get a ”step-by-step” evaluation in Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=148

Is it possible in Mathematica to get a step-by-step evaluation of some functions; that’s to say, outputting not only the result but all the stages that have led to it? If so, how does one do it?

asked by Cydonia7 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44 125 votes

answered by J. M.’s technical difficulties https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 105 votes

Is there any algorithm that runs faster in Mathematica than in C or Fortran?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=208045

I’m just curious. My friend just told me that Mathematica is mostly for symbolic calculation and not efficient for Numerical computations. He told me that’s the reason most of the people don’t use ...

asked by Gummala Navneeth https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66938 44 votes

answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 73 votes

2.22.3 Can you answer these questions?

   An apparent bug in Geometry‘ConvexHull2
   When making a package, how can I make a function that is already used by system?
   Simplifying expressions using elementary properties of integrals

An apparent bug in Geometry‘ConvexHull2

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224966

I was replacing some usages of Geometry‘ConvexHull2 with ConvexHullMesh and found one of my tests failing. It turned out the test asserted an incorrect expected result that agrees with the result of ...

asked by Vladimir Reshetnikov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7288 1 vote

When making a package, how can I make a function that is already used by system?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224730

Obviously, Plus[a,b] is given by Mathematica but say I have a package and I want to name a function Plus[a,b]. How can I go about making a new function without overwriting the original function ...

asked by Brandon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73362 2 votes

Simplifying expressions using elementary properties of integrals

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225023

I want to be able to use Simplify (or FullSimplify) to simplify expressions involving, for example, sums of integrals, for instance turning

∫           ∫
  b           c
   f(x)dx +    f (x )dx
 a           b

into

∫  c

  a

...

asked by Pillsy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=531 2 votes

2.23 Thursday, June 25, 2020

  2.23.1 Top new questions this week
  2.23.2 Greatest hits from previous weeks
  2.23.3 Can you answer these questions?

2.23.1 Top new questions this week

   Version 12.1.1 unable to type ”>
   Is there any better way to create a, a, a, b, b, b, b, b, c, c from a, 3, b, 5, c, 2?
   Selecting lists where all are prime
   Inverting replace direction
   Calculate Radius of Curvature
   Legendre expansion of the Dirac delta function
   Which methods are available for NDEigensystem?

Version 12.1.1 unable to type ”>”

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224461

Bug introduced in 12.1.1

Since I upgraded to version 12.1.1 I am unable to use > (Shift+.). When I type Shift+. the cell that I am typing in converts to Python. What am I doing wrong?

Steps to ...

asked by wdacda https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27856 15 votes

answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 10 votes

Is there any better way to create a, a, a, b, b, b, b, b, c, c from a, 3, b, 5, c, 2?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224581

My attempt:

data = {{a, 3}, {b, 5}, {c, 2}}; 
 
output = Table[#[[1]], #[[2]]] & /@ data // Flatten 
 
{a, a, a, b, b, b, b, b, c, c}

asked by Too Fat Man No Neck https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42141 11 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 18 votes

Selecting lists where all are prime

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224500

Given

    t={{7, 13, 19}, {13, 25, 37}, {19, 37, 55}, {25, 49, 73}, {31, 61, 91}, {37, 73, 109}} 
 
I want to select those lists where all three numbers are primes, so I should get 
{{7, 13, 19}, {37,  ...

asked by user57467 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57467 9 votes

answered by Pillsy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=531 12 votes

Inverting replace direction

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224314

I just have a simple problem. I have a list such that,

rep = { a1 -> b1, a2 -> b2, a3 -> b3}; 
 
I want to invert replace direction such that, 
{ b1 -> a1, b2 -> a2, b3 -> a3}

asked by Saesun Kim https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29998 8 votes

answered by PaulCommentary https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=54458 8 votes

Calculate Radius of Curvature

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224269

I have a list of coordinates that make a near-parabolic graph, which I managed to fit and calculate the curvature. However, the curvature only outputs a equation. Is there any way to calculate the ...

asked by Char https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66040 8 votes

answered by yarchik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9469 11 votes

Legendre expansion of the Dirac delta function

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224276

There is a known expansion for the Dirac delta function in the interval \( (-1, 1) \) in terms of the Legendre polynomials as

$$\delta(x) = \sum_{k = 0}^{\infty} (-1)^k \frac{(4k + 1) (2k)!}{2^{2k + 1}

asked by Novice https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72595 7 votes

answered by yarchik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9469 11 votes

Which methods are available for NDEigensystem?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224511

I am trying to find out what methods/options are available for NDEigensystem and descriptions of their use. Perusing the help, online Q&As, Mathematica’s in-line autofill, etc., I’ve found a few, ...

asked by Eli Lansey https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9 6 votes

answered by user21 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18437 5 votes

2.23.2 Greatest hits from previous weeks

   How can I save both the plot and the legend together?
   Formatting legend text font
   QR Code in shopping cart handle
   Solving \(L=\frac {3}{2} \sqrt {4 \pi ^2 A^2+W^2}-\frac {\sqrt {5 W \sqrt {4 \pi ^2 A^2+W^2}+6 \pi ^2 A^2+3 W^2}}{\sqrt {2}}+\frac {3 W}{2}\) for \(W\)
   1 Plot, 2 Scale/Axis
   What are the most common pitfalls awaiting new users?
   How to express trigonometric equation in terms of of given trigonometric function?

How can I save both the plot and the legend together?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=35653

In this example, how can I put the legend inside the graph? Currently, when I save the graph, only the graph is saved, not the legend.

Expr1 = -2 p + 1 
Expr2 = 2 p - 1 
Expr3 = p - 1/2 
Plot[{Expr1,  ...

asked by Mika Ike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6543 41 votes

answered by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 35 votes

Formatting legend text font

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3433

I am using this code to plot a graph, and I am trying to make the font of the legend bigger.

<<PlotLegends` 
ListLogLogPlot[{Sort[moby]}, PlotRange -> Full, Joined -> True,

asked by Julia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=525 20 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 25 votes

QR Code in shopping cart handle

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=26268

This week, the market people from my work wanted to put QR codes in shopping cart handles, but when they tested it, the QR code did not work. I noted that the cylindrical curvature (even small) ...

asked by Murta https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2266 194 votes

answered by halirutan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=187 190 votes

Solving \(L=\frac {3}{2} \sqrt {4 \pi ^2 A^2+W^2}-\frac {\sqrt {5 W \sqrt {4 \pi ^2 A^2+W^2}+6 \pi ^2 A^2+3 W^2}}{\sqrt {2}}+\frac {3 W}{2}\) for \(W\)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=57763

When I solve the aforementioned equation for \(W\) or \(A\) on Mathematica I get a long and ugly equation in return, namely one of the solutions for \(W\) is: (attempt to read at your own health)

asked by J.D’Almbert https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19257 8 votes

answered by Alexei Boulbitch https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=788 14 votes

1 Plot, 2 Scale/Axis

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=627

I would like to plot those two datasets on top of each other. But they have very different range on the \(y\) axis. How can I have two different axis?

I found the following on the help menu but quite ...

asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 145 votes

answered by ArgentoSapiens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=92 149 votes

What are the most common pitfalls awaiting new users?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18393

As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...

asked by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 462 votes

answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 279 votes

How to express trigonometric equation in terms of of given trigonometric function?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=434

How can I express a trigonometric equation / identity in terms of a given trigonometric function?

using following trigonometric identities

Sin[x]^2+Cos[x]^2==1 
Sin[x]/Cos[x]==Tan[x]

asked by Prashant Bhate https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=99 30 votes

answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 37 votes

2.23.3 Can you answer these questions?

   Using RegionPlot with NDSolve
   Implementing binomial expansion of (non-commuting) matrices in Mathematica
   Acquiring images from Zwo ASI camera in Mathematica Home Edition v 11.2.0.0

Using RegionPlot with NDSolve

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224477

So I have a DE which has no analytical solution and thus solved using NDSolve, involving some parameters like this:

solution=NDSolve[{b/z[t]^4+a z'[t]+z''[t]==0,z[0]==3,z'[0]==3},z,{t,0,5}]

I was ...

asked by t-smart https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53560 1 vote

Implementing binomial expansion of (non-commuting) matrices in Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224402

Given two matrices \(A\) and \(B\), their Binomial expansion is, in general, given by (see this page) \((A+B)^n = \sum \limits _{k=0, k=n[2]}^n \Bigg ( \sum \limits _{r=0}^k \binom {k}{r} A^r B^{k-r} \Bigg )\) ...

asked by Rob https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66809 1 vote

answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 0 votes

Acquiring images from Zwo ASI camera in Mathematica Home Edition v 11.2.0.0

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224258

I plan to use a ZWO ASI planetary camera (USB connection) for astronomical photography and would like to control the image acquisition using Mathematica. The issue is that although I have installed ...

asked by Dave Baker https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73406 1 vote

2.24 Thursday, June 18, 2020

  2.24.1 Top new questions this week
  2.24.2 Greatest hits from previous weeks
  2.24.3 Can you answer these questions?