7.40.1 Top new questions this week

7.40.1.1 Is there a simple way to convert " a,b,c " to "a,b,c"?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=258523

I need to use: 
 Composition[G][x] 
 
In the elements of the following list: 
 j = {{a, b, c}, {c, b, a}}; 
 
That is: I could do: 
... 
[list-manipulation]
 

asked by Red Banana https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=603 9 votes

answered by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 11 votes

7.40.1.2 How constrain 2d slider in Manipulate to a specified region?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=258746

In a  Manipulate , how can a 2D slider be constrained to a specified region  for example, to the unit disk $|z| \leq 1$in the following example? 
... 
[manipulate] [slider]
 

asked by murray https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=148 8 votes

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

7.40.1.3 Calculating the 3D Vector field of a permanent magnet with FEM

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=258480

trying to calculate the magnetic field of a permanent magnet using the finite element method I struggle setting up the equation system properly. In the end I want to be able to calculate the magnetic ... 
[differential-equations] [finite-element-method]
 

asked by Tschibi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42733 7 votes

answered by Alex Trounev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58388 5 votes

7.40.1.4 How can I self-define a keyboard entry for 3-dot "Because"?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=258538

In Mathematica, there already exists a keyboard entry for 3-dot "Therefore", which provides great convenience for input as shown below. 
 
However, I find it a little odd that for its ... 
[symbols] [keyboard] [logic] [input] [named-characters]
 

asked by AlbertLew https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=81664 6 votes

answered by Carl Lange https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57593 9 votes

7.40.1.5 How to obtain all subsets of a list with repetition?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=258495

I'd like to generate all lists of length  m  containing all possible element combinations from a given list of length  n  with ... 
[list-manipulation] [subset]
 

asked by Andrew https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=306 6 votes

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

7.40.1.6 How can I speed up RandomVariate in the following case?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=258605

I would like to generate random values of some parameter with the weight being the Poisson distribution. An important point is that each time I generate the random number I need to consider the ... 
[performance-tuning] [probability-or-statistics] [random]
 

asked by John Taylor https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=41058 5 votes

answered by JimB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19758 9 votes

7.40.1.7 `AccelerationOfFreeFall` has wrong units

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=258579

On earth, the acceleration of free fall is around $9.81\,\text{m}/\text{s}^2$. In Mathematica, 
... 
[units] [physical-constants]
 

asked by Roman https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26598 5 votes

answered by Bill Watts https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53121 1 vote