Re: [Getfem-users] Assembing finite element matrices in GetFem++

[Yves Renard]

Dear Marco,

if A(x), B(x) and C(x) are known matrix field described on a finite element method, you can use the generic assembly to compute your mass matrix, yes.
It should be similar to the mass matrix assembly in getfem_assembling.h adding the matrix fields. This should give something like

 generic_assembly assem;
  assem.set("A=data(qdim(#1),qdim(#1),#2); B=data(qdim(#1),qdim(#1),#2); C=data(qdim(#1),qdim(#1),#2); M(#1,#1)+=comp(Base(#2).Base(#2).Base(#2).vBase(#1).vBase(#1))(k,l,m,:,i,:,j).A(j,o,k).B(o,p,l).C(p,q,m);");
  assem.push_mi(mim);
  assem.push_mf(mf_u1);
  assem.push_mf(mf_data);
  assem.push_mat(M);
  assem.assembly(rg);

assuming that mf_data is a scalar fem.

Yves.


Le 07/10/2013 16:37, Marco Pischedda a écrit :

Dear all,

i'm a new user of GetFem++. 

I have a question for assembling a finite element matrix of the following type:

\int A(x)B(x)C(x) f(x) \dot v(x) dx

where A(x), B(x), C(x) are known finite element matrices, f(x)  is the unknown of the problem and v(x) is the test function. The problem is one-dimensional.

There is an example of this type of assembling on the tutorial? It is possible to assemble matrices of this type?

Thank's in advance

Marco Pischedda

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  Yves Renard (address@hidden)       tel : (33) 04.72.43.87.08
  Pole de Mathematiques, INSA-Lyon             fax : (33) 04.72.43.85.29
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