Re: [Getfem-users] Dirichlet conditions for vectorial problems

[Yves Renard]

On lundi 30 août 2010, Roman Putanowicz wrote:
> Dear All,
> 
> Let us assume that we have a vectorial problem (qdim = 2). The unknown
> vector field is U=(u1,u2). On boundary Gamma1 we set u1=0 and on boundary
> Gamma2 we set u2=0. The question is how to express this in GetFEM?
> 
> I have found that I can use the function:
> asm_generalized_dirichlet_constraints()
> but for that I have to construct a region representing sum of boundaries
> Gamma1 and Gamma2 and an appropriate matrix field that will filter the
> components of U.
> 
> The real question is: can I call the function
> asm_generalized_dirichlet_constraints()
> twice in my program, first for region corresponding to boundary Gamma1
> and then for the region corresponding to boundary Gamma2 ?
Yes, you can.
> 
> If yes, then how one should combine the matrices R and H filled by
> asm_generalized_dirichlet_constraints()
> before the call to Dirichlet_nullspace() ?
You just have to add them.



Note that it is also supported by the brick system.

Yves.

-- 

  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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  http://math.univ-lyon1.fr/~renard

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