Hi Abbas, thanks for the reply. I did debug with option A, but no error reported/no exception is thrown. To me, option A is the same as option B. However, the two generated system matrixs in the code are not the same.
On Thursday, September 28, 2023 at 10:27:17 AM UTC-7 abbas.b...@gmail.com wrote: > Did you try to run in Debug? If not give it a try and see if an exception > is thrown. > > Abbas > > On Thursday, September 28, 2023 at 3:15:14 AM UTC+2 hitl...@gmail.com > wrote: > >> Hello all, >> >> >> Previously, I initialized my system matrix in this way (option A) >> >> DoFTools::make_flux_sparsity_pattern(dof_handler, >> dsp, >> cell_coupling, >> face_coupling); >> constraints_newton_update.condense(dsp); >> SparsityTools::distribute_sparsity_pattern(dsp, >> hp_index_set, >> mpi_communicator, >> hp_relevant_set); >> system_matrix.reinit(hp_index_set, >> hp_index_set, >> dsp, >> mpi_communicator); >> >> However, the generated system matrix is singular. I was stuck by the >> singular matrix problem for about 2 weeks. >> >> >> Then, I initialized the matrix with option B, which generates a full rank >> matrix. Although, I don't see the difference between these 2 ways. Can >> someone explain this to me? Thans in advance. >> >> DoFTools::make_flux_sparsity_pattern(dof_handler, >> dsp, >> cell_coupling, >> face_coupling); >> constraints_newton_update.condense(dsp); >> sparsity_pattern.copy_from(dsp); >> system_matrix.reinit(hp_index_set, >> sparsity_pattern, >> mpi_communicator); >> > -- 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/fdcd61c9-ca93-4de7-b644-4b396defe09dn%40googlegroups.com.