Actual source code: ex32.c

petsc-3.3-p6 2013-02-11
  1: #include <petscdmda.h>

  5: static PetscErrorCode CompareGhostedCoords(Vec gc1,Vec gc2)
  6: {
  8:   PetscReal      nrm,gnrm;
  9:   Vec            tmp;

 12:   VecDuplicate(gc1,&tmp);
 13:   VecWAXPY(tmp,-1.0,gc1,gc2);
 14:   VecNorm(tmp,NORM_INFINITY,&nrm);
 15:   MPI_Allreduce(&nrm,&gnrm,1,MPIU_REAL,MPIU_MAX,PETSC_COMM_WORLD);
 16:   PetscPrintf(PETSC_COMM_WORLD,"norm of difference of ghosted coordinates %8.2e\n",gnrm);
 17:   VecDestroy(&tmp);
 18:   return(0);
 19: }

 23: static PetscErrorCode TestQ2Q1DA( void )
 24: {
 25:   DM             Q2_da,Q1_da,cda;
 26:   PetscInt       mx,my,mz;
 27:   Vec            coords,gcoords,gcoords2;

 30:   mx=7;
 31:   my=11;
 32:   mz=13;
 33:   ierr=DMDACreate3d(PETSC_COMM_WORLD,DMDA_BOUNDARY_NONE,DMDA_BOUNDARY_NONE,DMDA_BOUNDARY_NONE,DMDA_STENCIL_BOX,mx,my,mz,PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE,3,2,0,0,0,&Q2_da);
 34:   DMDASetUniformCoordinates(Q2_da,-1.0,1.0,-2.0,2.0,-3.0,3.0);
 35:   DMDAGetCoordinates(Q2_da,&coords);
 36:   DMDACreate3d(PETSC_COMM_WORLD,DMDA_BOUNDARY_NONE,DMDA_BOUNDARY_NONE,DMDA_BOUNDARY_NONE,DMDA_STENCIL_BOX,mx,my,mz,PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE,3,1,0,0,0,&Q1_da);
 37:   DMDASetCoordinates(Q1_da,coords);

 39:   /* Get ghost coordinates one way */
 40:   DMDAGetGhostedCoordinates(Q1_da,&gcoords);

 42:   /* And another */
 43:   DMDAGetCoordinates(Q1_da,&coords);
 44:   DMDAGetCoordinateDA(Q1_da,&cda);
 45:   DMGetLocalVector(cda,&gcoords2);
 46:   DMGlobalToLocalBegin(cda,coords,INSERT_VALUES,gcoords2);
 47:   DMGlobalToLocalEnd(cda,coords,INSERT_VALUES,gcoords2);

 49:   CompareGhostedCoords(gcoords,gcoords2);
 50:   DMRestoreLocalVector(cda,&gcoords2);

 52:   VecScale(coords,10.0);
 53:   VecScale(gcoords,10.0);
 54:   DMDAGetGhostedCoordinates(Q1_da,&gcoords2);
 55:   CompareGhostedCoords(gcoords,gcoords2);

 57:   DMDestroy(&Q2_da);
 58:   DMDestroy(&Q1_da);
 59:   return(0);
 60: }

 64: int main(int argc,char **argv)
 65: {

 68:   PetscInitialize(&argc,&argv,0,0);
 69:   TestQ2Q1DA();
 70:   PetscFinalize();
 71:   return 0;
 72: }