Re: Local stiffness matrix of an each element

[Yves Renard]

Dear Heungson Lee,

There is indeed no specific function to extract an elementary matrix in Getfem 
from the python interface. Of course, one way is to define a discontinuous 
element method corresponding to the finite element you use and then perform an 
assembly. Doing that, you will have separate elementary matrices ... 

If you just want to see what is going on with the elementary matrix, you can 
also just use the "Print" command of the weak form language (for instance for a 
Poisson problem "Print(Grad_u.Grad_Test_u)").

Best regards,

Yves


----- Mail original -----
De: "Heungson Lee" <heungson.lee@gmail.com>
À: "getfem-users" <getfem-users@nongnu.org>
Envoyé: Jeudi 18 Juin 2020 05:20:11
Objet: Local stiffness matrix of an each element

Dear getfem++ users. I am Heungson Lee.


I am having trouble finding a way to compute local matrices of elements.

To elaborate let's say I have a fem variable 'u' for a nonlinear problem
which is updated every load step.

With this 'u', I want to compute a local matrix of an element (for example
local stiffness matrix) and get eigenvalues of this matrix.

I was not able to find a way to do this.  FYI, I am using the python
interface.

I would really appreciate it if you could give me some advice on this.



Respectfully yours.