1 // Copyright (c) 2017-2026, Lawrence Livermore National Security, LLC and other CEED contributors.
2 // All Rights Reserved. See the top-level LICENSE and NOTICE files for details.
4 // SPDX-License-Identifier: BSD-2-Clause
12 // The example reads a mesh from a file and solves a simple linear system with a mass matrix (L2-pr…
15 // All libCEED objects use a Ceed device object constructed based on a command line argument (-ceed…
27 //     ./bp1 -ceed /cpu/self
28 //     ./bp1 -ceed /gpu/cuda
29 //     ./bp1 -m ../../../mfem/data/fichera.mesh
30 //     ./bp1 -m ../../../mfem/data/star.vtk -o 3
31 //     ./bp1 -m ../../../mfem/data/inline-segment.mesh -o 8
47 //TESTARGS -ceed {ceed_resource} -t -no-vis --size 2000 --order 4
49   // 1. Parse command-line options.  in main()
58   bool   test          = false;  in main()  local
62   args.AddOption(&ceed_spec, "-c", "-ceed", "Ceed specification.");  in main()
63   args.AddOption(&mesh_file, "-m", "--mesh", "Mesh file to use.");  in main()
64   args.AddOption(&order, "-o", "--order", "Finite element order (polynomial degree).");  in main()
65   args.AddOption(&max_nnodes, "-s", "--size", "Maximum size (number of DoFs)");  in main()
66 …args.AddOption(&visualization, "-vis", "--visualization", "-no-vis", "--no-visualization", "Enable…  in main()
67   args.AddOption(&test, "-t", "--test", "-no-test", "--no-test", "Enable or disable test mode.");  in main()
73   if (!test) {  in main()
83   int         dim  = mesh->Dimension();  in main()
89 … int ref_levels = (int)floor((log(max_nnodes / mesh->GetNE()) - dim * log(order)) / log(2.) / dim);  in main()
91       mesh->UniformRefinement();  in main()
94   if (mesh->GetNodalFESpace() == NULL) {  in main()
95     mesh->SetCurvature(1, false, -1, mfem::Ordering::byNODES);  in main()
97   if (mesh->NURBSext) {  in main()
98     mesh->SetCurvature(order, false, -1, mfem::Ordering::byNODES);  in main()
106   if (!test) {  in main()
107     std::cout << "Number of finite element unknowns: " << fespace->GetTrueVSize() << std::endl;  in main()
110 …// 6. Construct a rhs vector using the linear form f(v) = (solution, v), where v is a test functio…  in main()
121   cg.SetRelTol(1e-6);  in main()
123   if (test) {  in main()
136   if (!test) {  in main()
139     if (fabs(sol.ComputeL2Error(sol_coeff)) > 2e-4) {  in main()