Hi Wayne, you can attache your own constraints as shown here: https://github.com/dealii/dealii/blob/2376c62a4b89953b74801852983eb8556930d54d/tests/numerics/no_flux_18.cc#L1136-L1146
Hope this helps! Peter On Wednesday, 21 December 2022 at 02:44:42 UTC+1 yy.wayne wrote: > 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 dealii+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/688b2d12-1b11-4b78-92c0-f28b08e1c979n%40googlegroups.com.
