Actual source code: ex19.c
petsc-3.4.2 2013-07-02

      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]);

     24:           mystruct[i][j].inside[1] = 2.1;
     25:         }
     26:       }
     27:     }
     28:     DMDAVecRestoreArray(da,global,(void*) &mystruct);
     29:   }
     30:   return(0);
     31: }

     35: int main(int argc,char **argv)
     36: {
     37:   PetscInt       dof = 2,M = 3,N = 3,m = PETSC_DECIDE,n = PETSC_DECIDE;
     39:   DM             da;
     40:   Vec            global,local;

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

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

     51:   doit(da,global);

     54:   VecView(global,0);

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