static char help[] = "Tests MAIJ matrix for large DOF\n\n";

#include <petscdm.h>
#include <petscdmda.h>

int main(int argc, char *argv[])
{
  Mat M;
  Vec x, y;
  DM  da, daf;

  PetscFunctionBeginUser;
  PetscCall(PetscInitialize(&argc, &argv, 0, help));
  PetscCall(DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DMDA_STENCIL_STAR, 4, 5, PETSC_DECIDE, PETSC_DECIDE, 41, 1, 0, 0, &da));
  PetscCall(DMSetFromOptions(da));
  PetscCall(DMSetUp(da));
  PetscCall(DMRefine(da, PETSC_COMM_WORLD, &daf));
  PetscCall(DMCreateInterpolation(da, daf, &M, NULL));
  PetscCall(DMCreateGlobalVector(da, &x));
  PetscCall(DMCreateGlobalVector(daf, &y));

  PetscCall(MatMult(M, x, y));
  PetscCall(MatMultTranspose(M, y, x));
  PetscCall(DMDestroy(&da));
  PetscCall(DMDestroy(&daf));
  PetscCall(VecDestroy(&x));
  PetscCall(VecDestroy(&y));
  PetscCall(MatDestroy(&M));
  PetscCall(PetscFinalize());
  return 0;
}

/*TEST

   test:
      nsize: 2
      output_file: output/empty.out

TEST*/