xref: /petsc/src/dm/impls/moab/tests/ex1.cxx (revision ef46b1a67e276116c83b5d4ce8efc2932ea4fc0a)
1 static char help[] = "Simple MOAB example\n\n";
2 
3 #include <petscdmmoab.h>
4 #include "moab/ScdInterface.hpp"
5 
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;
14 
15 PetscErrorCode ProcessOptions(MPI_Comm comm, AppCtx *options)
16 {
17   PetscBool      flg;
18 
19   PetscFunctionBegin;
20   PetscCall(PetscStrcpy(options->filename, ""));
21   PetscCall(PetscStrcpy(options->tagname, "petsc_tag"));
22   options->dim = -1;
23 
24   PetscOptionsBegin(comm, "", "MOAB example options", "DMMOAB");
25   PetscCall(PetscOptionsRangeInt("-dim", "The topological mesh dimension", "ex1.cxx", options->dim, &options->dim, NULL,PETSC_DECIDE,3));
26   PetscCall(PetscOptionsString("-filename", "The file containing the mesh", "ex1.cxx", options->filename, options->filename, sizeof(options->filename), NULL));
27   PetscCall(PetscOptionsString("-tagname", "The tag name from which to create a vector", "ex1.cxx", options->tagname, options->tagname, sizeof(options->tagname), &flg));
28   PetscOptionsEnd();
29 
30   PetscCall(PetscLogEventRegister("CreateMesh",          DM_CLASSID,   &options->createMeshEvent));
31   PetscFunctionReturn(0);
32 }
33 
34 PetscErrorCode CreateMesh(MPI_Comm comm, AppCtx *user, DM *dm)
35 {
36   moab::Interface *iface=NULL;
37   moab::Tag tag=NULL;
38   moab::Tag ltog_tag=NULL;
39   moab::Range range;
40   PetscInt tagsize;
41   moab::ErrorCode merr;
42 
43   PetscFunctionBegin;
44   PetscCall(PetscLogEventBegin(user->createMeshEvent,0,0,0,0));
45   PetscCall(DMMoabCreateMoab(comm, iface, &ltog_tag, &range, dm));
46   std::cout << "Created DMMoab using DMMoabCreateMoab." << std::endl;
47   PetscCall(DMMoabGetInterface(*dm, &iface));
48 
49     // load file and get entities of requested or max dimension
50   if (strlen(user->filename) > 0) {
51     merr = iface->load_file(user->filename);MBERRNM(merr);
52     std::cout << "Read mesh from file " << user->filename << std::endl;
53   }
54   else {
55       // make a simple structured mesh
56     moab::ScdInterface *scdi;
57     merr = iface->query_interface(scdi);
58 
59     moab::ScdBox *box;
60     merr = scdi->construct_box (moab::HomCoord(0,0,0), moab::HomCoord(5,5,5), NULL, 0, box);MBERRNM(merr);
61     user->dim = 3;
62     merr = iface->set_dimension(user->dim);MBERRNM(merr);
63     std::cout << "Created structured 5x5x5 mesh." << std::endl;
64   }
65   if (-1 == user->dim) {
66     moab::Range tmp_range;
67     merr = iface->get_entities_by_handle(0, tmp_range);MBERRNM(merr);
68     if (tmp_range.empty()) {
69       MBERRNM(moab::MB_FAILURE);
70     }
71     user->dim = iface->dimension_from_handle(*tmp_range.rbegin());
72   }
73   merr = iface->get_entities_by_dimension(0, user->dim, range);MBERRNM(merr);
74   PetscCall(DMMoabSetLocalVertices(*dm, &range));
75 
76     // get the requested tag and create if necessary
77   std::cout << "Creating tag with name: " << user->tagname << ";\n";
78   merr = iface->tag_get_handle(user->tagname, 1, moab::MB_TYPE_DOUBLE, tag, moab::MB_TAG_CREAT | moab::MB_TAG_DENSE);MBERRNM(merr);
79   {
80       // initialize new tag with gids
81     std::vector<double> tag_vals(range.size());
82     merr = iface->tag_get_data(ltog_tag, range, tag_vals.data());MBERRNM(merr); // read them into ints
83     double *dval = tag_vals.data(); int *ival = reinterpret_cast<int*>(dval); // "stretch" them into doubles, from the end
84     for (int i = tag_vals.size()-1; i >= 0; i--) dval[i] = ival[i];
85     merr = iface->tag_set_data(tag, range, tag_vals.data());MBERRNM(merr); // write them into doubles
86   }
87   merr = iface->tag_get_length(tag, tagsize);MBERRNM(merr);
88 
89   PetscCall(DMSetUp(*dm));
90 
91     // create the dmmoab and initialize its data
92   PetscCall(PetscObjectSetName((PetscObject) *dm, "MOAB mesh"));
93   PetscCall(PetscLogEventEnd(user->createMeshEvent,0,0,0,0));
94   user->dm = *dm;
95   PetscFunctionReturn(0);
96 }
97 
98 int main(int argc, char **argv)
99 {
100   AppCtx            user;                 /* user-defined work context */
101   moab::ErrorCode   merr;
102   Vec               vec;
103   moab::Interface*  mbImpl=NULL;
104   moab::Tag         datatag=NULL;
105 
106   PetscCall(PetscInitialize(&argc, &argv, NULL,help));
107   PetscCall(ProcessOptions(PETSC_COMM_WORLD, &user));
108 
109   PetscCall(CreateMesh(PETSC_COMM_WORLD, &user, &user.dm)); /* create the MOAB dm and the mesh */
110 
111   PetscCall(DMMoabGetInterface(user.dm, &mbImpl));
112   merr = mbImpl->tag_get_handle(user.tagname, datatag);MBERRNM(merr);
113   PetscCall(DMMoabCreateVector(user.dm, datatag, NULL, PETSC_TRUE, PETSC_FALSE,&vec)); /* create a vec from user-input tag */
114 
115   std::cout << "Created VecMoab from existing tag." << std::endl;
116   PetscCall(VecDestroy(&vec));
117   std::cout << "Destroyed VecMoab." << std::endl;
118   PetscCall(DMDestroy(&user.dm));
119   std::cout << "Destroyed DMMoab." << std::endl;
120   PetscCall(PetscFinalize());
121   return 0;
122 }
123 
124 /*TEST
125 
126      build:
127        requires: moab
128 
129      test:
130 
131 TEST*/
132