Actual source code: ex14.c

petsc-3.4.2 2013-07-02
  2: static char help[] = "Tests saving DMDA vectors to files.\n\n";

  4: /*
  5:     ex13.c reads in the DMDA and vector written by this program.
  6: */

  8: #include <petscdmda.h>

 12: int main(int argc,char **argv)
 13: {
 14:   PetscMPIInt    rank;
 15:   PetscInt       M = 10,N = 8,m = PETSC_DECIDE,n = PETSC_DECIDE, dof = 1;
 17:   DM             da;
 18:   Vec            local,global,natural;
 19:   PetscScalar    value;
 20:   PetscViewer    bviewer;

 22:   PetscInitialize(&argc,&argv,(char*)0,help);

 24:   /* Read options */
 25:   PetscOptionsGetInt(NULL,"-M",&M,NULL);
 26:   PetscOptionsGetInt(NULL,"-N",&N,NULL);
 27:   PetscOptionsGetInt(NULL,"-m",&m,NULL);
 28:   PetscOptionsGetInt(NULL,"-n",&n,NULL);
 29:   PetscOptionsGetInt(NULL,"-dof",&dof,NULL);

 31:   /* Create distributed array and get vectors */
 32:   DMDACreate2d(PETSC_COMM_WORLD, DMDA_BOUNDARY_NONE, DMDA_BOUNDARY_NONE,DMDA_STENCIL_BOX,
 33:                       M,N,m,n,dof,1,NULL,NULL,&da);
 34:   DMCreateGlobalVector(da,&global);
 35:   DMCreateLocalVector(da,&local);

 37:   value = -3.0;
 38:   VecSet(global,value);
 39:   DMGlobalToLocalBegin(da,global,INSERT_VALUES,local);
 40:   DMGlobalToLocalEnd(da,global,INSERT_VALUES,local);

 42:   MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
 43:   value = rank+1;
 44:   VecScale(local,value);
 45:   DMLocalToGlobalBegin(da,local,ADD_VALUES,global);
 46:   DMLocalToGlobalEnd(da,local,ADD_VALUES,global);

 48:   DMDACreateNaturalVector(da,&natural);
 49:   DMDAGlobalToNaturalBegin(da,global,INSERT_VALUES,natural);
 50:   DMDAGlobalToNaturalEnd(da,global,INSERT_VALUES,natural);

 52:   DMDASetFieldName(da,0,"First field");
 53:   /*  VecView(global,PETSC_VIEWER_DRAW_WORLD); */

 55:   PetscViewerBinaryOpen(PETSC_COMM_WORLD,"daoutput",FILE_MODE_WRITE,&bviewer);
 56:   DMView(da,bviewer);
 57:   VecView(global,bviewer);
 58:   PetscViewerDestroy(&bviewer);

 60:   /* Free memory */
 61:   VecDestroy(&local);
 62:   VecDestroy(&global);
 63:   VecDestroy(&natural);
 64:   DMDestroy(&da);
 65:   PetscFinalize();
 66:   return 0;
 67: }