Re: Local stiffness matrix of an each element

[Heungson Lee]

Thank you. Your advice is of great help to me. I've tried interpolating variables from original elements to discontinuous elements and assembling the matrices with those variables for each nonlinear load step. It seems that it works well.

Respectfully yours.  

On Sun, Jun 21, 2020 at 3:33 AM Yves Renard <yves.renard@insa-lyon.fr> wrote:

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.