[Getfem-users] Introduction of a constant into the assembly process

[Véronique Pham]

Hi everyone,

I would
like to ask an other question about the assembling using the getfem generic_assembly procedure.
I'm trying to solve

that kind of equation : eta*u – \delta u = f,

where eta is a real type constant.

What is the best way to introduce this constant into the assembly process?
I’m thinking of using the “generic
mass matrix assembly with an additional parameter” of the library. The code should be :

{

   getfem::generic_assembly assem;

   assem.push_mi(mim);
   assem.push_mf(mf_u);

   assem.push_data(std::vector<T>(mf_u.nb_dof(),eta));
   assem.push_mat(A);

   assem.set("F=data(#1);"
                   "M(#1,#1)+=sym(comp(Base(#1).Base(#1).Base(#1))(:,:,i).F(i));");
   assem.assembly();
}

Instead of using “assem.push_data(std::vector<T>(mf_u.nb_dof(),eta))” part, which is ineficient, should I create a mesh with a big quad element and a P0 shape function?

Thanks for your help.

Veronique.