Alex, If you can formulate your problem/approach in a way (iteratively?) that you could solve separately on the three triangulations (using input from the solution on the other triangulations), that might be easier. On the other hand, if you only want one system matrix you would identify matching dofs manually and merge the system matrices manually. Maybe, someone else has better ideas and more experience than me. I'm still curious how your full weak form looks like.
Best, Daniel On Fri, Oct 27, 2023 at 1:42 PM Alex Quinlan <alex.r.quin...@gmail.com> wrote: > Hi Daniel, > > Thanks for the response. I am essentially using the approach in Step-8, > where I am seeking a vector-valued displacement solution using FE_System. > So, I've been using: > > dealii::FESystem<3>(FE_Q<3>(1), 3 ) > and > dealii::FESystem<2,3>(FE_Q<2,3>(1), 3 ) > > > Based on your suggestion, I am picturing doing something like this: > > // Shared Objects > AffineConstraints<double> constraints; > SparsityPattern sparsity_pattern; > SparseMatrix<double> system_matrix; > Vector<double> solution; // This is the solution vector > Vector<double> system_rhs; // This is the load / right-hand-side vector > > // Dimension dependent objects > // 3D > Triangulation<3,3> triangulation_3D; > DoFHandler<3,3> dof_handler_3D; > FESystem<3,3> fe_3D; > > // 2D > Triangulation<2,3> triangulation_2D; > DoFHandler<2,3> dof_handler_2D; > FESystem<2,3> fe_2D; > > // 1D > Triangulation<1,3> triangulation_1D; > DoFHandler<1,3> dof_handler_1D; > FESystem<1,3> fe_1D; > > Then I need to proceed with each of these triangulations, and *somehow* > link them together within the system_matrix and system_rhs. > > I have been building the system matrix using this line for each cell in > the dof_handler.active_cell_iterators: > > constraints.distribute_local_to_global( cell_matrix, cell_rhs, > local_dof_indices, > system_matrix, system_rhs); > > I see two challenges using this: > 1) keeping track of the dof_indices across 3 dof_handlers so they can be > added to the correct place in the system_matrix > 2) Connecting the triangulations within the system matrix. > > > Have I understood your suggestion correctly? Do you forsee any other > challenges? > > Thanks very much, > Alex > > -- > 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/7b15f86c-0069-42c9-b7ed-4bde752ee07bn%40googlegroups.com > <https://groups.google.com/d/msgid/dealii/7b15f86c-0069-42c9-b7ed-4bde752ee07bn%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- 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/CAOYDWbJ4%3DYfq4F3mwEf8co64Gs__dqFu8oTBGofTnr3dxKE8Mg%40mail.gmail.com.
