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
10 …es a simple usage of libCEED to compute the volume of a 3D body using matrix-free application of a…
15 // The example has no dependencies, and is designed to be self-contained.
18 // All libCEED objects use a Ceed device object constructed based on a command line argument (-ceed…
22 //     make ex3-volume [CEED_DIR=</path/to/libceed>]
24 // Sample runs:
26 //     ./ex3-volume
27 //     ./ex3-volume -ceed /cpu/self
28 //     ./ex3-volume -ceed /gpu/cuda
30 // Test in 1D-3D
31 //TESTARGS(name="1D User QFunction") -ceed {ceed_resource} -d 1 -t
32 //TESTARGS(name="2D User QFunction") -ceed {ceed_resource} -d 2 -t
33 //TESTARGS(name="3D User QFunction") -ceed {ceed_resource} -d 3 -t
38 #include "ex3-volume.h"
61   CeedInt     prob_size   = -1;              // approximate problem size  in main()
68     if (!strcmp(argv[ia], "-h")) {  in main()
70     } else if (!strcmp(argv[ia], "-c") || !strcmp(argv[ia], "-ceed")) {  in main()
72     } else if (!strcmp(argv[ia], "-d")) {  in main()
75     } else if (!strcmp(argv[ia], "-m")) {  in main()
77     } else if (!strcmp(argv[ia], "-p")) {  in main()
79     } else if (!strcmp(argv[ia], "-q")) {  in main()
81     } else if (!strcmp(argv[ia], "-s")) {  in main()
83     } else if (!strcmp(argv[ia], "-b")) {  in main()
85     } else if (!strcmp(argv[ia], "-t")) {  in main()
100     printf("  Ceed specification     [-c] : %s\n", ceed_spec);  in main()
101     printf("  Mesh dimension         [-d] : %" CeedInt_FMT "\n", dim);  in main()
102     printf("  Mesh degree            [-m] : %" CeedInt_FMT "\n", mesh_degree);  in main()
103     printf("  Solution degree        [-p] : %" CeedInt_FMT "\n", sol_degree);  in main()
104     printf("  Num. 1D quadrature pts [-q] : %" CeedInt_FMT "\n", num_qpts);  in main()
105     printf("  Approx. # unknowns     [-s] : %" CeedInt_FMT "\n", prob_size);  in main()
108       printf("Test/quiet mode is %s\n", (test ? "ON" : "OFF (use -t to enable)"));  in main()
115   // Select appropriate backend and logical device based on the (-ceed) command line argument.  in main()
126   // Determine the mesh size based on the given approximate problem size.  in main()
217   // Create auxiliary solution-size vectors.  in main()
229   // Benchmark runs  in main()
232     printf(" Executing %d benchmarking runs...\n", benchmark);  in main()
256     printf("Volume error         : % .14g\n", volume - exact_volume);  in main()
259     CeedScalar tol = (dim == 1 ? 200. * CEED_EPSILON : dim == 2 ? 1E-5 : 1E-5);  in main()
261     if (fabs(volume - exact_volume) > tol) printf("Volume error : % .1e\n", volume - exact_volume);  in main()
300       r--;  in GetCartesianMeshSize()
316     nd[d] = num_xyz[d] * (p - 1) + 1;  in BuildCartesianRestriction()
320   // elem:         0             1                 n-1  in BuildCartesianRestriction()
321   //           |---*-...-*---|---*-...-*---|- ... -|--...--|  in BuildCartesianRestriction()
322   // num_nodes:   0   1    p-1  p  p+1       2*p             n*p  in BuildCartesianRestriction()
338         g_nodes += (e_xyz[d] * (p - 1) + r_nodes % p) * g_nodes_stride;  in BuildCartesianRestriction()
361     nd[d] = num_xyz[d] * (p - 1) + 1;  in SetCartesianMeshCoords()
370   CeedLobattoQuadrature(p, nodes, NULL);  // nodes are in [-1,1]  in SetCartesianMeshCoords()
377       coords[gs_nodes + scalar_size * d] = ((d_1d / (p - 1)) + nodes[d_1d % (p - 1)]) / num_xyz[d];  in SetCartesianMeshCoords()
399       coords[i] = 0.5 + 1. / sqrt(3.) * sin((2. / 3.) * M_PI * (coords[i] - 0.5));  in TransformMeshCoords()