1: static char help[] = "Create a Plex sphere from quads and create a P1 section\n\n";

  3: #include <petscdmplex.h>

  5: static PetscErrorCode SetupSection(DM dm)
  6: {
  7:   PetscSection s;
  8:   PetscInt     vStart, vEnd, v;

 10:   PetscFunctionBeginUser;
 11:   PetscCall(DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd));
 12:   PetscCall(PetscSectionCreate(PetscObjectComm((PetscObject)dm), &s));
 13:   PetscCall(PetscSectionSetNumFields(s, 1));
 14:   PetscCall(PetscSectionSetFieldComponents(s, 0, 1));
 15:   PetscCall(PetscSectionSetChart(s, vStart, vEnd));
 16:   for (v = vStart; v < vEnd; ++v) {
 17:     PetscCall(PetscSectionSetDof(s, v, 1));
 18:     PetscCall(PetscSectionSetFieldDof(s, v, 0, 1));
 19:   }
 20:   PetscCall(PetscSectionSetUp(s));
 21:   PetscCall(DMSetLocalSection(dm, s));
 22:   PetscCall(PetscSectionDestroy(&s));
 23:   PetscFunctionReturn(PETSC_SUCCESS);
 24: }

 26: int main(int argc, char **argv)
 27: {
 28:   DM  dm;
 29:   Vec u;

 31:   PetscFunctionBeginUser;
 32:   PetscCall(PetscInitialize(&argc, &argv, NULL, help));
 33:   PetscCall(DMCreate(PETSC_COMM_WORLD, &dm));
 34:   PetscCall(DMSetType(dm, DMPLEX));
 35:   PetscCall(DMSetFromOptions(dm));
 36:   PetscCall(PetscObjectSetName((PetscObject)dm, "Sphere"));
 37:   PetscCall(DMViewFromOptions(dm, NULL, "-dm_view"));

 39:   PetscCall(SetupSection(dm));
 40:   PetscCall(DMGetGlobalVector(dm, &u));
 41:   PetscCall(VecSet(u, 2));
 42:   PetscCall(VecViewFromOptions(u, NULL, "-vec_view"));
 43:   PetscCall(DMRestoreGlobalVector(dm, &u));
 44:   PetscCall(DMDestroy(&dm));
 45:   PetscCall(PetscFinalize());
 46:   return 0;
 47: }

 49: /*TEST

 51:   testset:
 52:     requires: !__float128
 53:     args: -dm_plex_shape sphere -dm_view

 55:     test:
 56:       suffix: 2d_quad
 57:       args: -dm_plex_simplex 0

 59:     test:
 60:       suffix: 2d_tri
 61:       args:

 63:     test:
 64:       suffix: 3d_tri
 65:       args: -dm_plex_dim 3

 67:   testset:
 68:     requires: !__float128
 69:     args: -dm_plex_shape sphere -petscpartitioner_type simple -dm_view

 71:     test:
 72:       suffix: 2d_quad_parallel
 73:       nsize: 2
 74:       args: -dm_plex_simplex 0

 76:     test:
 77:       suffix: 2d_tri_parallel
 78:       nsize: 2

 80:     test:
 81:       suffix: 3d_tri_parallel
 82:       nsize: 2
 83:       args: -dm_plex_dim 3

 85: TEST*/