Alberto, Now I understand your concern. The boolean flag that is passed as the final > parameter to MatrixTools::apply_boundary_values > <https://www.dealii.org/8.5.0/doxygen/deal.II/namespaceMatrixTools.html#a9ad0eb7a8662628534586716748d62fb> > > determines whether column elimination is performed. You've set it to false, > so this is not done and the RHS is unaltered. So switching it to true (the > default) should preserve the symmetry of the system and make the necessary > adjustments to the RHS vector. > While this is true in general, for PETSc and Trilinos matrices only the case "eliminate_columns = false" is implemented [1]. This means that your system matrix will not be symmetric if you are using MatrixTools::apply_boundary_values, but a CG will likely still work [2, Global elimination].
Best, Daniel [1] https://www.dealii.org/developer/doxygen/deal.II/namespaceMatrixTools.html#a96d8a143c787e0dca41ce6168152dc04 [2] https://www.dealii.org/developer/doxygen/deal.II/namespaceMatrixTools.html -- 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. For more options, visit https://groups.google.com/d/optout.
