7.13.1 Top new questions this week

7.13.1.1 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. 
... 
[list-manipulation] [functions] [data] [filtering]
 

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

7.13.1.2 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. ... 
[differential-equations] [finite-element-method] [boundary-conditions] [fluid-dynamics]
 

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

7.13.1.3 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 ... 
[combinatorics] [number-theory]
 

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

7.13.1.4 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 ... 
[mathematical-optimization]
 

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

7.13.1.5 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, ... 
[computational-geometry] [polygons]
 

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

7.13.1.6 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 
[matrix]
 

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

7.13.1.7 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 ... 
[graphs-and-networks] [pattern-matching]
 

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