Actual source code: ex37.c


  2: static char help[] = "VecView() with a DMDA1d vector and draw viewer.\n\n";

  4: #include <petscdm.h>
  5: #include <petscdmda.h>
  6: #include <petscao.h>

  8: PetscErrorCode apply(void *ctx, PetscInt n, const PetscScalar *x, PetscScalar *y)
  9: {
 10:   PetscInt i;

 12:   for (i = 0; i < n; i++) {
 13:     y[3 * i]     = x[i];
 14:     y[3 * i + 1] = x[i] * x[i];
 15:     y[3 * i + 2] = x[i] * x[i] * x[i];
 16:   }
 17:   return PETSC_SUCCESS;
 18: }

 20: int main(int argc, char **argv)
 21: {
 22:   DM  da;
 23:   Vec global;
 24:   PF  pf;

 26:   PetscFunctionBeginUser;
 27:   PetscCall(PetscInitialize(&argc, &argv, (char *)0, help));
 28:   PetscCall(DMDACreate1d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, 10, 3, 1, NULL, &da));
 29:   PetscCall(DMSetFromOptions(da));
 30:   PetscCall(DMSetUp(da));
 31:   PetscCall(DMCreateGlobalVector(da, &global));
 32:   PetscCall(PFCreate(PETSC_COMM_WORLD, 1, 3, &pf));
 33:   PetscCall(PFSet(pf, apply, NULL, NULL, NULL, NULL));
 34:   PetscCall(PFApplyVec(pf, NULL, global));
 35:   PetscCall(PFDestroy(&pf));
 36:   PetscCall(VecView(global, PETSC_VIEWER_DRAW_WORLD));
 37:   PetscCall(VecDestroy(&global));
 38:   PetscCall(DMDestroy(&da));
 39:   PetscCall(PetscFinalize());
 40:   return 0;
 41: }

 43: /*TEST

 45:    test:
 46:       nsize: 2
 47:       requires: x

 49: TEST*/