Actual source code: ex41.c

  1: static char help[] = "Test -dm_preallocate_only with DMStag\n\n";

  3: #include <petscdm.h>
  4: #include <petscdmstag.h>

  6: int main(int argc, char **argv)
  7: {
  8:   DM            dm;
  9:   PetscInt      dim;
 10:   Mat           A;
 11:   DMStagStencil row, col;
 12:   PetscScalar   value;

 15:   PetscInitialize(&argc, &argv, (char *)0, help);
 16:   dim = 1;
 17:   PetscOptionsGetInt(NULL, NULL, "-dim", &dim, NULL);

 19:   switch (dim) {
 20:   case 1:
 21:     DMStagCreate1d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, 4, 1, 1, DMSTAG_STENCIL_BOX, 1, NULL, &dm);
 22:     break;
 23:   default:
 24:     SETERRQ(PETSC_COMM_WORLD, PETSC_ERR_SUP, "Unsupported dimension %" PetscInt_FMT, dim);
 25:   }
 26:   DMSetFromOptions(dm);
 27:   DMSetUp(dm);

 29:   DMCreateMatrix(dm, &A);

 31:   row.c   = 0;
 32:   row.i   = 0;
 33:   row.loc = DMSTAG_ELEMENT;

 35:   col.c   = 0;
 36:   col.i   = 1;
 37:   col.loc = DMSTAG_ELEMENT;

 39:   value = 1.234;

 41:   DMStagMatSetValuesStencil(dm, A, 1, &row, 1, &col, &value, INSERT_VALUES);
 42:   MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY);
 43:   MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY);

 45:   MatView(A, PETSC_VIEWER_STDOUT_WORLD);

 47:   MatDestroy(&A);
 48:   DMDestroy(&dm);
 49:   PetscFinalize();
 50:   return 0;
 51: }

 53: /*TEST

 55:    test:
 56:      args: -dm_preallocate_only

 58: TEST*/