Actual source code: ex19.c

petsc-3.3-p6 2013-02-11
  2: static char help[] = "Tests DMDA with variable multiple degrees of freedom per node.\n\n";

  4: /*
  5:    This code only compiles with gcc, since it is not ANSI C
  6: */

  8: #include <petscdmda.h>

 10: PetscErrorCode doit(DM da,Vec global)
 11: {
 13:   PetscInt       i,j,k,M,N,dof;

 15:   DMDAGetInfo(da,0,&M,&N,0,0,0,0,&dof,0,0,0,0,0);
 16:   {
 17:     struct {PetscScalar inside[dof];} **mystruct;
 18:     DMDAVecGetArray(da,global,(void*) &mystruct);
 19:     for ( i=0; i<N; i++) {
 20:       for ( j=0; j<M; j++) {
 21:         for ( k=0; k<dof; k++) {
 22:           PetscPrintf(PETSC_COMM_WORLD,"%d %d %G\n",i,j,mystruct[i][j].inside[0]);
 23:           mystruct[i][j].inside[1] = 2.1;
 24:         }
 25:       }
 26:     }
 27:     DMDAVecRestoreArray(da,global,(void*) &mystruct);
 28:   }
 29:   return(0);
 30: }

 34: int main(int argc,char **argv)
 35: {
 36:   PetscInt       dof = 2,M = 3,N = 3,m = PETSC_DECIDE,n = PETSC_DECIDE;
 38:   DM             da;
 39:   Vec            global,local;
 40: 
 41:   PetscInitialize(&argc,&argv,(char*)0,help);

 43:   PetscOptionsGetInt(0,"-dof",&dof,0);
 44:   /* Create distributed array and get vectors */
 45:   DMDACreate2d(PETSC_COMM_WORLD, DMDA_BOUNDARY_NONE, DMDA_BOUNDARY_NONE,DMDA_STENCIL_BOX,
 46:                     M,N,m,n,dof,1,PETSC_NULL,PETSC_NULL,&da);
 47:   DMCreateGlobalVector(da,&global);
 48:   DMCreateLocalVector(da,&local);

 50:   doit(da,global);


 53:   VecView(global,0);

 55:   /* Free memory */
 56:   VecDestroy(&local);
 57:   VecDestroy(&global);
 58:   DMDestroy(&da);
 59:   PetscFinalize();
 60:   return 0;
 61: }
 62: