2: static char help[] = "Tests DMDA interpolation for coarse DM on a subset of processors.\n\n";

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

  7: int main(int argc,char **argv)
  8: {
  9:   PetscInt       M = 14,dof = 1,s = 1,ratio = 2,dim = 2;
 11:   DM             da_c,da_f;
 12:   Vec            v_c,v_f;
 13:   Mat            I;
 14:   PetscScalar    one = 1.0;
 15:   MPI_Comm       comm_f, comm_c;

 17:   PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
 18:   PetscOptionsGetInt(NULL,NULL,"-dim",&dim,NULL);
 19:   PetscOptionsGetInt(NULL,NULL,"-M",&M,NULL);
 20:   PetscOptionsGetInt(NULL,NULL,"-sw",&s,NULL);
 21:   PetscOptionsGetInt(NULL,NULL,"-ratio",&ratio,NULL);
 22:   PetscOptionsGetInt(NULL,NULL,"-dof",&dof,NULL);

 24:   comm_f = PETSC_COMM_WORLD;
 25:   DMDASplitComm2d(comm_f,M,M,s,&comm_c);

 27:   /* Set up the array */
 28:   if (dim == 2) {
 29:     DMDACreate2d(comm_c,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,M,M,PETSC_DECIDE,PETSC_DECIDE,dof,s,NULL,NULL,&da_c);
 30:     M    = ratio*(M-1) + 1;
 31:     DMDACreate2d(comm_f,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,M,M,PETSC_DECIDE,PETSC_DECIDE,dof,s,NULL,NULL,&da_f);
 32:   }
 33:   DMSetFromOptions(da_c);
 34:   DMSetUp(da_c);CHKERRQ(ierr)
 35:   DMSetFromOptions(da_f);
 36:   DMSetUp(da_f);

 38:   DMCreateGlobalVector(da_c,&v_c);
 39:   DMCreateGlobalVector(da_f,&v_f);

 41:   VecSet(v_c,one);
 42:   DMCreateInterpolation(da_c,da_f,&I,NULL);
 43:   MatInterpolate(I,v_c,v_f);
 44:   VecView(v_f,PETSC_VIEWER_STDOUT_(comm_f));
 45:   MatRestrict(I,v_f,v_c);
 46:   VecView(v_c,PETSC_VIEWER_STDOUT_(comm_c));

 48:   MatDestroy(&I);
 49:   VecDestroy(&v_c);
 50:   DMDestroy(&da_c);
 51:   VecDestroy(&v_f);
 52:   DMDestroy(&da_f);
 53:   PetscFinalize();
 54:   return ierr;
 55: }