From: Marc Fehling Date: Wed, 4 Sep 2024 20:49:29 +0000 (+0200) Subject: Enhance the original failing make_consistent_in_parallel test. X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F17611%2Fhead;p=dealii.git Enhance the original failing make_consistent_in_parallel test. --- diff --git a/tests/lac/constraints_make_consistent_in_parallel_06.cc b/tests/lac/constraints_make_consistent_in_parallel_06.cc index ab168c1daf..3df979daab 100644 --- a/tests/lac/constraints_make_consistent_in_parallel_06.cc +++ b/tests/lac/constraints_make_consistent_in_parallel_06.cc @@ -1,7 +1,7 @@ // ------------------------------------------------------------------------ // // SPDX-License-Identifier: LGPL-2.1-or-later -// Copyright (C) 2018 - 2023 by the deal.II authors +// Copyright (C) 2024 by the deal.II authors // // This file is part of the deal.II library. // @@ -13,9 +13,44 @@ // ------------------------------------------------------------------------ +// Test AffineConstraints::make_consistent_in_parallel() for the case where +// constraints need to be combined between different ranks. We consider the +// following tricky hp-scenario on two MPI processes: +// +// subd 0 | subd 1 +// | +// +---+---+---+---+ +// | | | | | +// | 2 | 3 | 3 | 2 | +// | | | | | +// +---X-+-+-+-+---+ +// | |2|2|2|2| | +// | 2 +-+-+-+-+ 2 | +// | |2|2|2|2| | +// +---+-+-+-+-+---+ +// | +// subd 0 | subd 1 +// +// Consider the edge marked with 'X'; in particular, DoFs 63 and 64 which solely +// belong to the Q3 element and are hanging nodes on that edge. +// +// The DoFs of the Q3 element are constrained against the coarse Q2 elements. +// The DoFs of the fine Q2 elements are also constrained against the coarse Q2 +// elements. DoFTools::make_hanging_node_constraints() resolves these +// constraints correctly, and they are correct for process 0 on subdomain 0. +// +// From the point of view of process 1, the coarse Q2 elements on subdomain 0 +// are artificial and their DoFs are thus not part of its locally relevant DoFs. +// Hence for the given context, DoFTools::make_hanging_node_constraints() +// constrains the DoFs of the Q3 element against the fine Q2 elements. +// As process 1 does not know about the coarse Q2 elements, i.e., for the given +// LOCAL context on process 1, these are indeed the correct constraints. +// +// However in the GLOBAL context, the constraints are wrong on process 1. +// They are only assembled correctly on process 0. Thus, we need +// AffineConstraints::make_consistent_in_parallel() to distribute these +// constraints correctly. -// test AffineConstraints::make_consistent_in_parallel for case -// where constraints need to be combined between different ranks #include @@ -31,96 +66,143 @@ #include +#include + #include "../tests.h" -using namespace dealii; void test() { - static const int dim = 3; - static const int spacedim = 3; + constexpr int dim = 3; + constexpr int spacedim = 3; + // set up grid parallel::distributed::Triangulation triangulation( MPI_COMM_WORLD); + { + std::vector repetitions({4, 2, 1}); + Point bottom_left(-2, -1, 0); + Point top_right(2, 1, 1); + + GridGenerator::subdivided_hyper_rectangle(triangulation, + repetitions, + bottom_left, + top_right); + } + + // set up hp-refinement in center part DoFHandler dof_handler(triangulation); - + { + for (const auto &cell : dof_handler.active_cell_iterators() | + IteratorFilters::LocallyOwnedCell()) + { + const auto ¢er = cell->center(); + if (std::abs(center[0]) < 1.) + { + if (center[1] > 0.) + cell->set_active_fe_index(1); + else + cell->set_refine_flag(); + } + } + triangulation.execute_coarsening_and_refinement(); + } + + // enumerate dofs hp::FECollection fe_collection; - - IndexSet locally_active_dofs; - IndexSet locally_relevant_dofs; - - std::vector repetitions({4, 2, 1}); - Point bottom_left(-2, -1, 0); - Point top_right(2, 1, 1); - - GridGenerator::subdivided_hyper_rectangle(triangulation, - repetitions, - bottom_left, - top_right); - - // hp-refine center part - for (const auto &cell : dof_handler.active_cell_iterators() | - IteratorFilters::LocallyOwnedCell()) - { - cell->set_active_fe_index(1); - - const auto ¢er = cell->center(); - if (std::abs(center[0]) < 1.) + { + fe_collection.push_back(FE_Q(2)); + fe_collection.push_back(FE_Q(3)); + dof_handler.distribute_dofs(fe_collection); + } + +#if false + // output vtu + DataOut data_out; + { + Vector fe_degrees(triangulation.n_active_cells()); + for (const auto &cell : dof_handler.active_cell_iterators() | + IteratorFilters::LocallyOwnedCell()) + fe_degrees(cell->active_cell_index()) = cell->get_fe().degree; + + Vector subdomain(triangulation.n_active_cells()); + for (auto &subd : subdomain) + subd = triangulation.locally_owned_subdomain(); + + data_out.attach_dof_handler(dof_handler); + data_out.add_data_vector(fe_degrees, "fe_degrees"); + data_out.add_data_vector(subdomain, "subdomain"); + data_out.build_patches(); + + data_out.write_vtu_in_parallel("output.vtu", + dof_handler.get_mpi_communicator()); + } +#endif + + // miscellaneous + const auto show_constraints_63_64 = + [&](const AffineConstraints &constraints) { + const unsigned int my_id = + Utilities::MPI::this_mpi_process(MPI_COMM_WORLD); + for (const unsigned int dof : {63, 64}) { - if (center[1] > 0.) - cell->set_active_fe_index(2); - else - cell->set_refine_flag(); + deallog << "What process " << my_id << " believes about DoF " << dof + << ":" << std::endl; + for (const auto &c : constraints.get_lines()) + if (c.index == dof) + for (const auto &entry : c.entries) + deallog << " constrained against " << entry.first + << " with weight " << entry.second << std::endl; } - } - - triangulation.execute_coarsening_and_refinement(); - - // set dofs - for (unsigned int degree = 1; degree <= 10; ++degree) - fe_collection.push_back(FE_Q(degree)); - dof_handler.distribute_dofs(fe_collection); + }; const IndexSet &locally_owned_dofs = dof_handler.locally_owned_dofs(); - locally_active_dofs = DoFTools::extract_locally_active_dofs(dof_handler); - locally_relevant_dofs = DoFTools::extract_locally_relevant_dofs(dof_handler); - AffineConstraints constraints(locally_owned_dofs, - locally_relevant_dofs); - - const auto show_constraints_63_64 = [&]() { - deallog << "What process " - << Utilities::MPI::this_mpi_process(MPI_COMM_WORLD) - << " believes about DoF 63:" << std::endl; - for (const auto &c : constraints.get_lines()) - if (c.index == 63) - for (const auto &entry : c.entries) - deallog << " constrained against " << entry.first - << " with weight " << entry.second << std::endl; - deallog << "What process " - << Utilities::MPI::this_mpi_process(MPI_COMM_WORLD) - << " believes about DoF 64:" << std::endl; - for (const auto &c : constraints.get_lines()) - if (c.index == 64) - for (const auto &entry : c.entries) - deallog << " constrained against " << entry.first - << " with weight " << entry.second << std::endl; - }; - - - deallog << "------------- make_hanging_node_constraints():" << std::endl; - DoFTools::make_hanging_node_constraints(dof_handler, constraints); - show_constraints_63_64(); - - deallog << "------------- make_consistent_in_parallel():" << std::endl; - constraints.make_consistent_in_parallel(locally_owned_dofs, - locally_relevant_dofs, - dof_handler.get_communicator()); - show_constraints_63_64(); + const IndexSet locally_active_dofs = + DoFTools::extract_locally_active_dofs(dof_handler); + const IndexSet locally_relevant_dofs = + DoFTools::extract_locally_relevant_dofs(dof_handler); + + // make hanging node constraints + AffineConstraints constraints; + { + constraints.reinit(locally_owned_dofs, locally_relevant_dofs); + + deallog << "------------- make_hanging_node_constraints():" << std::endl; + DoFTools::make_hanging_node_constraints(dof_handler, constraints); + show_constraints_63_64(constraints); + } + + // make consistent in parallel on locally active dofs + AffineConstraints constraints_active; + { + constraints_active.copy_from(constraints); + + deallog << "------------- make_consistent_in_parallel() " + << "on locally active dofs:" << std::endl; + constraints_active.make_consistent_in_parallel( + locally_owned_dofs, + locally_active_dofs, + dof_handler.get_mpi_communicator()); + show_constraints_63_64(constraints_active); + } + + // make consistent in parallel on locally relevant dofs + AffineConstraints constraints_relevant; + { + constraints_relevant.copy_from(constraints); + + deallog << "------------- make_consistent_in_parallel() " + << "on locally relevant dofs:" << std::endl; + constraints_relevant.make_consistent_in_parallel( + locally_owned_dofs, + locally_relevant_dofs, + dof_handler.get_mpi_communicator()); + show_constraints_63_64(constraints_relevant); + } } - int main(int argc, char *argv[]) { diff --git a/tests/lac/constraints_make_consistent_in_parallel_06.mpirun=2.output b/tests/lac/constraints_make_consistent_in_parallel_06.mpirun=2.output index ef5a5e273a..e0b7bef8e2 100644 --- a/tests/lac/constraints_make_consistent_in_parallel_06.mpirun=2.output +++ b/tests/lac/constraints_make_consistent_in_parallel_06.mpirun=2.output @@ -8,7 +8,16 @@ DEAL:0::What process 0 believes about DoF 64: DEAL:0:: constrained against 3 with weight -0.123607 DEAL:0:: constrained against 7 with weight 0.323607 DEAL:0:: constrained against 19 with weight 0.800000 -DEAL:0::------------- make_consistent_in_parallel(): +DEAL:0::------------- make_consistent_in_parallel() on locally active dofs: +DEAL:0::What process 0 believes about DoF 63: +DEAL:0:: constrained against 3 with weight 0.323607 +DEAL:0:: constrained against 7 with weight -0.123607 +DEAL:0:: constrained against 19 with weight 0.800000 +DEAL:0::What process 0 believes about DoF 64: +DEAL:0:: constrained against 3 with weight -0.123607 +DEAL:0:: constrained against 7 with weight 0.323607 +DEAL:0:: constrained against 19 with weight 0.800000 +DEAL:0::------------- make_consistent_in_parallel() on locally relevant dofs: DEAL:0::What process 0 believes about DoF 63: DEAL:0:: constrained against 3 with weight 0.323607 DEAL:0:: constrained against 7 with weight -0.123607 @@ -24,7 +33,10 @@ DEAL:1::What process 1 believes about DoF 64: DEAL:1:: constrained against 3 with weight -0.447214 DEAL:1:: constrained against 7 with weight 0.447214 DEAL:1:: constrained against 63 with weight 1.00000 -DEAL:1::------------- make_consistent_in_parallel(): +DEAL:1::------------- make_consistent_in_parallel() on locally active dofs: +DEAL:1::What process 1 believes about DoF 63: +DEAL:1::What process 1 believes about DoF 64: +DEAL:1::------------- make_consistent_in_parallel() on locally relevant dofs: DEAL:1::What process 1 believes about DoF 63: DEAL:1:: constrained against 3 with weight 0.323607 DEAL:1:: constrained against 7 with weight -0.123607