[Getfem-users] Dirichlet conditions for vectorial problems

[Roman Putanowicz]

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 ?

If yes, then how one should combine the matrices R and H filled by
asm_generalized_dirichlet_constraints() 
before the call to Dirichlet_nullspace() ?

I would appreciate any hint.

Regards

Roman
-- 
Roman Putanowicz, PhD  < address@hidden  >
Institute for Computational Civil Engng (L-5)
Dept. of Civil Engng, Cracow Univ. of Technology
www.l5.pk.edu.pl, tel. +48 12 628 2569, fax 2034