2: static char help[] = "Demonstrates various vector routines for DMDA.\n\n";

  4: /*
  5:   Include "petscpf.h" so that we can use pf functions and "petscdmda.h" so
  6:  we can use the PETSc distributed arrays
  7: */

  9: #include <petscpf.h>
 10: #include <petscdm.h>
 11: #include <petscdmda.h>

 13: PetscErrorCode myfunction(void *ctx, PetscInt n, const PetscScalar *xy, PetscScalar *u)
 14: {
 15:   PetscInt i;

 18:   for (i = 0; i < n; i++) {
 19:     u[2 * i]     = xy[2 * i];
 20:     u[2 * i + 1] = xy[2 * i + 1];
 21:   }
 22:   return 0;
 23: }

 25: int main(int argc, char **argv)
 26: {
 27:   Vec      u, xy;
 28:   DM       da;
 29:   PetscInt m = 10, n = 10, dof = 2;
 30:   PF       pf;

 33:   PetscInitialize(&argc, &argv, (char *)0, help);
 34:   DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DMDA_STENCIL_BOX, m, n, PETSC_DECIDE, PETSC_DECIDE, dof, 1, 0, 0, &da);
 35:   DMSetFromOptions(da);
 36:   DMSetUp(da);
 37:   DMDASetUniformCoordinates(da, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
 38:   DMCreateGlobalVector(da, &u);
 39:   DMGetCoordinates(da, &xy);

 41:   DMDACreatePF(da, &pf);
 42:   PFSet(pf, myfunction, 0, 0, 0, 0);
 43:   PFSetFromOptions(pf);

 45:   PFApplyVec(pf, xy, u);

 47:   VecView(u, PETSC_VIEWER_DRAW_WORLD);

 49:   /*
 50:      Free work space.  All PETSc objects should be destroyed when they
 51:      are no longer needed.
 52:   */
 53:   VecDestroy(&u);
 54:   PFDestroy(&pf);
 55:   DMDestroy(&da);
 56:   PetscFinalize();
 57:   return 0;
 58: }

 60: /*TEST

 62:    test:

 64: TEST*/