Actual source code: ex32.c
petsc-3.12.4 2020-02-04
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      1: static char help[] = "Tests DMDA ghost coordinates\n\n";

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

      6: static PetscErrorCode CompareGhostedCoords(Vec gc1,Vec gc2)
      7: {
      9:   PetscReal      nrm,gnrm;
     10:   Vec            tmp;

     13:   VecDuplicate(gc1,&tmp);
     14:   VecWAXPY(tmp,-1.0,gc1,gc2);
     15:   VecNorm(tmp,NORM_INFINITY,&nrm);
     16:   MPI_Allreduce(&nrm,&gnrm,1,MPIU_REAL,MPIU_MAX,PETSC_COMM_WORLD);
     17:   PetscPrintf(PETSC_COMM_WORLD,"norm of difference of ghosted coordinates %8.2e\n",gnrm);
     18:   VecDestroy(&tmp);
     19:   return(0);
     20: }

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

     29:   mx   = 7;
     30:   my   = 11;
     31:   mz   = 13;
     32:   DMDACreate3d(PETSC_COMM_WORLD,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,mx,my,mz,PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE,3,2,0,0,0,&Q2_da);
     33:   DMSetFromOptions(Q2_da);
     34:   DMSetUp(Q2_da);
     35:   DMDASetUniformCoordinates(Q2_da,-1.0,1.0,-2.0,2.0,-3.0,3.0);
     36:   DMGetCoordinates(Q2_da,&coords);
     37:   DMDACreate3d(PETSC_COMM_WORLD,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,mx,my,mz,PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE,3,1,0,0,0,&Q1_da);
     38:   DMSetFromOptions(Q1_da);
     39:   DMSetUp(Q1_da);
     40:   DMSetCoordinates(Q1_da,coords);

     42:   /* Get ghost coordinates one way */
     43:   DMGetCoordinatesLocal(Q1_da,&gcoords);

     45:   /* And another */
     46:   DMGetCoordinates(Q1_da,&coords);
     47:   DMGetCoordinateDM(Q1_da,&cda);
     48:   DMGetLocalVector(cda,&gcoords2);
     49:   DMGlobalToLocalBegin(cda,coords,INSERT_VALUES,gcoords2);
     50:   DMGlobalToLocalEnd(cda,coords,INSERT_VALUES,gcoords2);

     52:   CompareGhostedCoords(gcoords,gcoords2);
     53:   DMRestoreLocalVector(cda,&gcoords2);

     55:   VecScale(coords,10.0);
     56:   VecScale(gcoords,10.0);
     57:   DMGetCoordinatesLocal(Q1_da,&gcoords2);
     58:   CompareGhostedCoords(gcoords,gcoords2);

     60:   DMDestroy(&Q2_da);
     61:   DMDestroy(&Q1_da);
     62:   return(0);
     63: }

     65: int main(int argc,char **argv)
     66: {

     69:   PetscInitialize(&argc,&argv,0,help);if (ierr) return ierr;
     70:   TestQ2Q1DA();
     71:   PetscFinalize();
     72:   return ierr;
     73: }

     76: /*TEST

     78:    test:
     79:       nsize: 2

     81: TEST*/