6.29.3 Can you answer these questions?

6.29.3.1 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 ... 
[matrix] [expression-construction]
 

asked by Stijn https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69486 2 votes

6.29.3.2 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 ... 
[differential-equations] [finite-element-method]
                                                                                  

                                                                                  
 

asked by George Varnavides https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=41179 1 vote

6.29.3.3 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 ... 
[cellular-automata]
 

asked by Joana Bugalho https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75694 2 votes