7.38.2 Greatest hits from previous weeks

7.38.2.1 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. 
 
... 
[list-manipulation]
 

asked by PeterR https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=140 71 votes

answered by J. M.'s torpor https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 68 votes

7.38.2.2 How to make the digits of  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 
 
[graphics] [formatting] [generative-art]
 

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

7.38.2.3 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 ... 
[plotting] [differential-equations]
 

asked by Matt Groff https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1735 36 votes

answered by Peter Breitfeld https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=307 29 votes

7.38.2.4 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 ... 
[plotting] [graphics] [code-request]
 

asked by Mel https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=3249 30 votes

answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 51 votes

7.38.2.5 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 ... 
[plotting] [generative-art]
 

asked by Amatya https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2039 625 votes

answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 491 votes

7.38.2.6 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? 
 
... 
[plotting]
 

asked by sjdh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=515 71 votes

answered by Ajasja https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=745 88 votes

7.38.2.7 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? 
[export] [matlab]
 

asked by Seyhmus Güngören https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4256 44 votes

answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 49 votes