Actual source code: ex1.cxx
petsc-3.10.5 2019-03-28
1: static char help[] = "Simple MOAB example\n\n";
3: #include <petscdmmoab.h>
4: #include "moab/ScdInterface.hpp"
6: typedef struct {
7: DM dm; /* DM implementation using the MOAB interface */
8: PetscLogEvent createMeshEvent;
9: /* Domain and mesh definition */
10: PetscInt dim;
11: char filename[PETSC_MAX_PATH_LEN];
12: char tagname[PETSC_MAX_PATH_LEN];
13: } AppCtx;
15: PetscErrorCode ProcessOptions(MPI_Comm comm, AppCtx *options)
16: {
18: PetscBool flg;
21: PetscStrcpy(options->filename, "");
22: PetscStrcpy(options->tagname, "petsc_tag");
23: options->dim = -1;
25: PetscOptionsBegin(comm, "", "MOAB example options", "DMMOAB");
26: PetscOptionsInt("-dim", "The topological mesh dimension", "ex1.cxx", options->dim, &options->dim, NULL);
27: PetscOptionsString("-filename", "The file containing the mesh", "ex1.cxx", options->filename, options->filename, sizeof(options->filename), NULL);
28: PetscOptionsString("-tagname", "The tag name from which to create a vector", "ex1.cxx", options->tagname, options->tagname, sizeof(options->tagname), &flg);
29: PetscOptionsEnd();
31: PetscLogEventRegister("CreateMesh", DM_CLASSID, &options->createMeshEvent);
32: return(0);
33: }
35: PetscErrorCode CreateMesh(MPI_Comm comm, AppCtx *user, DM *dm)
36: {
37: moab::Interface *iface=NULL;
38: moab::Tag tag=NULL;
39: moab::Tag ltog_tag=NULL;
40: moab::Range range;
41: PetscInt tagsize;
42: moab::ErrorCode merr;
46: PetscLogEventBegin(user->createMeshEvent,0,0,0,0);
47: DMMoabCreateMoab(comm, iface, <og_tag, &range, dm);
48: std::cout << "Created DMMoab using DMMoabCreateMoab." << std::endl;
49: DMMoabGetInterface(*dm, &iface);
51: // load file and get entities of requested or max dimension
52: if (strlen(user->filename) > 0) {
53: merr = iface->load_file(user->filename);MBERRNM(merr);
54: std::cout << "Read mesh from file " << user->filename << std::endl;
55: }
56: else {
57: // make a simple structured mesh
58: moab::ScdInterface *scdi;
59: merr = iface->query_interface(scdi);
61: moab::ScdBox *box;
62: merr = scdi->construct_box (moab::HomCoord(0,0,0), moab::HomCoord(5,5,5), NULL, 0, box);MBERRNM(merr);
63: user->dim = 3;
64: merr = iface->set_dimension(user->dim);MBERRNM(merr);
65: std::cout << "Created structured 5x5x5 mesh." << std::endl;
66: }
67: if (-1 == user->dim) {
68: moab::Range tmp_range;
69: merr = iface->get_entities_by_handle(0, tmp_range);MBERRNM(merr);
70: if (tmp_range.empty()) {
71: MBERRNM(moab::MB_FAILURE);
72: }
73: user->dim = iface->dimension_from_handle(*tmp_range.rbegin());
74: }
75: merr = iface->get_entities_by_dimension(0, user->dim, range);MBERRNM(merr);
76: DMMoabSetLocalVertices(*dm, &range);
78: // get the requested tag and create if necessary
79: std::cout << "Creating tag with name: " << user->tagname << ";\n";
80: merr = iface->tag_get_handle(user->tagname, 1, moab::MB_TYPE_DOUBLE, tag, moab::MB_TAG_CREAT | moab::MB_TAG_DENSE);MBERRNM(merr);
81: {
82: // initialize new tag with gids
83: std::vector<double> tag_vals(range.size());
84: merr = iface->tag_get_data(ltog_tag, range, tag_vals.data());MBERRNM(merr); // read them into ints
85: double *dval = tag_vals.data(); int *ival = reinterpret_cast<int*>(dval); // "stretch" them into doubles, from the end
86: for (int i = tag_vals.size()-1; i >= 0; i--) dval[i] = ival[i];
87: merr = iface->tag_set_data(tag, range, tag_vals.data());MBERRNM(merr); // write them into doubles
88: }
89: merr = iface->tag_get_length(tag, tagsize);MBERRNM(merr);
91: DMSetUp(*dm);
93: // create the dmmoab and initialize its data
94: PetscObjectSetName((PetscObject) *dm, "MOAB mesh");
95: PetscLogEventEnd(user->createMeshEvent,0,0,0,0);
96: user->dm = *dm;
97: return(0);
98: }
100: int main(int argc, char **argv)
101: {
102: AppCtx user; /* user-defined work context */
103: moab::ErrorCode merr;
104: PetscErrorCode ierr;
105: Vec vec;
106: moab::Interface* mbImpl=NULL;
107: moab::Tag datatag=NULL;
109: PetscInitialize(&argc, &argv, NULL,help);if (ierr) return ierr;
110: ProcessOptions(PETSC_COMM_WORLD, &user);
112: CreateMesh(PETSC_COMM_WORLD, &user, &user.dm); /* create the MOAB dm and the mesh */
114: DMMoabGetInterface(user.dm, &mbImpl);
115: merr = mbImpl->tag_get_handle(user.tagname, datatag);MBERRNM(merr);
116: DMMoabCreateVector(user.dm, datatag, NULL, PETSC_TRUE, PETSC_FALSE,&vec); /* create a vec from user-input tag */
118: std::cout << "Created VecMoab from existing tag." << std::endl;
119: VecDestroy(&vec);
120: std::cout << "Destroyed VecMoab." << std::endl;
121: DMDestroy(&user.dm);
122: std::cout << "Destroyed DMMoab." << std::endl;
123: PetscFinalize();
124: return ierr;
125: }