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

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

  7: PetscErrorCode apply(PetscCtx ctx, PetscInt n, const PetscScalar *x, PetscScalar *y)
  8: {
  9:   for (PetscInt i = 0; i < n; i++) {
 10:     y[3 * i]     = x[i];
 11:     y[3 * i + 1] = x[i] * x[i];
 12:     y[3 * i + 2] = x[i] * x[i] * x[i];
 13:   }
 14:   return PETSC_SUCCESS;
 15: }

 17: int main(int argc, char **argv)
 18: {
 19:   DM  da;
 20:   Vec global;
 21:   PF  pf;

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

 40: /*TEST

 42:    test:
 43:       nsize: 2
 44:       requires: x
 45:       output_file: output/empty.out

 47: TEST*/