xref: /petsc/src/dm/impls/plex/tests/ex75.c (revision 62ed42821f84f33353546905c9271ed730d39ff0)
1 static char help[] = "Tests for submesh with both CG and DG coordinates\n\n";
2 
3 #include <petscdmplex.h>
4 #include <petsc/private/dmimpl.h>
5 
main(int argc,char ** argv)6 int main(int argc, char **argv)
7 {
8   PetscInt       dim = 1, d, cStart, cEnd, c, q, degree = 2, coordSize, offset;
9   PetscReal      R = 1.0;
10   DM             dm, coordDM, subdm;
11   PetscSection   coordSec;
12   Vec            coordVec;
13   PetscScalar   *coords;
14   DMLabel        filter;
15   const PetscInt filterValue = 1;
16   MPI_Comm       comm;
17   PetscMPIInt    size;
18 
19   PetscFunctionBeginUser;
20   PetscCall(PetscInitialize(&argc, &argv, NULL, help));
21   comm = PETSC_COMM_WORLD;
22   PetscCallMPI(MPI_Comm_size(comm, &size));
23   if (size != 1) {
24     PetscCall(PetscPrintf(comm, "This example is specifically designed for comm size == 1.\n"));
25     PetscCall(PetscFinalize());
26     return 0;
27   }
28   /* Make a unit circle with 16 elements. */
29   PetscCall(DMPlexCreateSphereMesh(comm, dim, PETSC_TRUE, R, &dm));
30   PetscUseTypeMethod(dm, createcellcoordinatedm, &coordDM);
31   PetscCall(DMSetCellCoordinateDM(dm, coordDM));
32   PetscCall(DMDestroy(&coordDM));
33   PetscCall(DMGetCellCoordinateSection(dm, &coordSec));
34   PetscCall(PetscSectionSetNumFields(coordSec, 1));
35   PetscCall(PetscSectionSetFieldComponents(coordSec, 0, dim));
36   PetscCall(DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd));
37   PetscCall(PetscSectionSetChart(coordSec, cStart, cEnd));
38   for (c = cStart; c < cEnd; ++c) {
39     PetscCall(PetscSectionSetDof(coordSec, c, dim * (degree + 1)));
40     PetscCall(PetscSectionSetFieldDof(coordSec, c, 0, dim * (degree + 1)));
41   }
42   PetscCall(PetscSectionSetUp(coordSec));
43   PetscCall(PetscSectionGetStorageSize(coordSec, &coordSize));
44   PetscCall(VecCreate(PETSC_COMM_SELF, &coordVec));
45   PetscCall(PetscObjectSetName((PetscObject)coordVec, "cellcoordinates"));
46   PetscCall(VecSetBlockSize(coordVec, dim));
47   PetscCall(VecSetSizes(coordVec, coordSize, PETSC_DETERMINE));
48   PetscCall(VecSetType(coordVec, VECSTANDARD));
49   PetscCall(VecGetArray(coordVec, &coords));
50   for (c = cStart; c < cEnd; ++c) {
51     PetscCall(PetscSectionGetOffset(coordSec, c, &offset));
52     for (q = 0; q < degree + 1; ++q) {
53       /* Make some DG coordinates. Note that dim = 1.*/
54       for (d = 0; d < dim; ++d) coords[offset + dim * q + d] = 100. + (PetscScalar)c + (1.0 / (PetscScalar)degree) * (PetscScalar)q;
55     }
56   }
57   PetscCall(VecRestoreArray(coordVec, &coords));
58   PetscCall(DMSetCellCoordinatesLocal(dm, coordVec));
59   PetscCall(VecDestroy(&coordVec));
60   /* Make submesh. */
61   PetscCall(DMLabelCreate(PETSC_COMM_SELF, "filter", &filter));
62   PetscCall(DMLabelSetValue(filter, 15, filterValue)); /* last cell */
63   PetscCall(DMPlexFilter(dm, filter, filterValue, PETSC_FALSE, PETSC_FALSE, PetscObjectComm((PetscObject)dm), NULL, &subdm));
64   PetscCall(DMLabelDestroy(&filter));
65   PetscCall(PetscObjectSetName((PetscObject)subdm, "Example_SubDM"));
66   PetscCall(DMViewFromOptions(subdm, NULL, "-dm_view"));
67   PetscCall(DMDestroy(&subdm));
68   PetscCall(DMDestroy(&dm));
69   PetscCall(PetscFinalize());
70   return 0;
71 }
72 
73 /*TEST
74 
75   test:
76     suffix: 0
77     args: -dm_view ascii::ascii_info_detail
78 
79 TEST*/
80