An alternative choice is applying the boundary conditions weakly(during assemble). Will weakly implemented boundary condition behaves worse than explicitly through AffineConstraint class, when it's not Dirichlet BC? 在2022年12月21日星期三 UTC+8 09:44:42<yy.wayne> 写道：
> Hi guys, I have a question on setting the boundary constraints for > mg_constrained_dofs object. > In many problems where the only boundary conditions(for AffineConstraints) > are Dirichlet BC and hanging nodes, mg_constrained knows them by > MGConstrainedDoFs::make_zero_boundary_constraints(the Dirichlet boundary > id, not necessarily zero) and > MGConstrainedDoFs::initialize(dof_handler)(the hanging nodes), respectively. > However, in case other BC like compute_normal_flux_constraints or > compute_no_normal_flux_constraints exists, mg_constrained_dofs has no way > to include it. Therefore the MGLevelObject mg_matrices is intrinsically > different to global system_matrix. Then mg_matrices[0] cannot be a good > approximation of coarsest grid. > Is there some hint for such cases? > -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/4ca7f505-332c-4b9d-ac48-249af61267bdn%40googlegroups.com.
