Dear all,
I use FEniCS with c++ interface to solve multiscale FEM. I only succeed with version 1.0 because I need to define two or more periodic boundary conditions on the same mesh. It seems to be impossible with the new version.
Is there a way to apply more than one boundary condition on the same mesh in version 1.2 ?
For example in the version 1.0 I define two sub-domains for a UnitSquare mesh :
/**
* Sub-domain to define the periodicity for height.
*
*/
bool MicroScale::PeriodicSubdomainHeight::inside(const Array& x, bool on_boundary) const {
return fabs(x[1]) < 0.00005;
}
void MicroScale::PeriodicSubdomainHeight::map(const Array& x, Array& y) const {
y[0] = x[0];
y[1] = x[1] - 1;
}
/**
* Sub-domain to define the periodicity for width.
*
*/
bool MicroScale::PeriodicSubdomainWidth::inside(const Array& x, bool on_boundary) const {
return fabs(x[0]) < 0.00005;
}
void MicroScale::PeriodicSubdomainWidth::map(const Array& x, Array& y) const {
y[0] = x[0] - 1;
y[1] = x[1];
}
\And then, later in the code I declare the two periodic boundary conditions :
// Set up boundary condition for height
PeriodicSubdomainHeight psh;
PeriodicBC pbch(V, psh);
// Set up Boundary condition for width
PeriodicSubdomainWidth psw;
PeriodicBC pbcw(V, psw);
// Collect boundary conditions
std::vector bcs;
bcs.push_back(&pbcw);
bcs.push_back(&pbch);
// Define variational problem
//[...] I skip the definition part cause it is not really interesting, I think.
LinearVariationalProblem problem(a, L, u, bcs);
It works perfectly well with this version, but when I try to do it in version 1.1,
an error occurs. I can only use one boundary condition. (I haven't try yet with the version 1.2).
And I have an other problem: is there a way to replace the second part of equation u(X) - u(X') = 0 in the new version ? I need to replace the 0 by another member.
For the second question, I can modify the periodic boundary myself, if there is no other solution, but the first question is a real problem for me. I can't update my version.
thank you for your help and your attention,
Abdallah.
