Actual source code: ex11.c

petsc-3.4.2 2013-07-02
  2: static char help[] = "Tests various 2-dimensional DMDA routines.\n\n";

  4: #include <petscdmda.h>
  5: #include <petscdraw.h>

  9: int main(int argc,char **argv)
 10: {
 11:   PetscInt       M = 5,N = 4,dof=1,s=1,bx=0,by=0,i,n,j,k,m,cnt,wrap;
 13:   DM             da;
 14:   PetscViewer    viewer;
 15:   Vec            local,locala,global,coors;
 16:   PetscScalar    *xy,*alocal;
 17:   PetscDraw      draw;
 18:   char           fname[16];

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

 22:   /* Create viewers */
 23:   PetscViewerDrawOpen(PETSC_COMM_WORLD,0,"",PETSC_DECIDE,PETSC_DECIDE,600,200,&viewer);
 24:   PetscViewerDrawGetDraw(viewer,0,&draw);
 25:   PetscDrawSetDoubleBuffer(draw);

 27:   /* Read options */
 28:   PetscOptionsGetInt(NULL,"-M",&M,NULL);
 29:   PetscOptionsGetInt(NULL,"-N",&N,NULL);
 30:   PetscOptionsGetInt(NULL,"-dof",&dof,NULL);
 31:   PetscOptionsGetInt(NULL,"-s",&s,NULL);
 32:   PetscOptionsGetInt(NULL,"-periodic_x",&wrap,NULL);
 33:   PetscOptionsGetInt(NULL,"-periodic_y",&wrap,NULL);

 35:   /* Create distributed array and get vectors */
 36:   DMDACreate2d(PETSC_COMM_WORLD,(DMDABoundaryType)bx,(DMDABoundaryType)by,DMDA_STENCIL_BOX,M,N,PETSC_DECIDE,
 37:                       PETSC_DECIDE,dof,s,NULL,NULL,&da);
 38:   DMDASetUniformCoordinates(da,0.0,1.0,0.0,1.0,0.0,0.0);
 39:   for (i=0; i<dof; i++) {
 40:     sprintf(fname,"Field %d",(int)i);
 41:     DMDASetFieldName(da,i,fname);
 42:   }

 44:   DMView(da,viewer);
 45:   DMCreateGlobalVector(da,&global);
 46:   DMCreateLocalVector(da,&local);
 47:   DMCreateLocalVector(da,&locala);
 48:   DMGetCoordinates(da,&coors);
 49:   VecGetArray(coors,&xy);

 51:   VecView(coors,PETSC_VIEWER_STDOUT_SELF);

 53:   /* Set values into local vectors */
 54:   VecGetArray(local,&alocal);
 55:   DMDAGetGhostCorners(da,0,0,0,&m,&n,0);
 56:   n    = n/dof;
 57:   for (k=0; k<dof; k++) {
 58:     cnt = 0;
 59:     for (j=0; j<n; j++) {
 60:       for (i=0; i<m; i++) {
 61:         alocal[k+dof*cnt] = PetscSinScalar(2.0*PETSC_PI*(k+1)*xy[2*cnt]);
 62:         cnt++;
 63:       }
 64:     }
 65:   }
 66:   VecRestoreArray(local,&alocal);
 67:   VecRestoreArray(coors,&xy);

 69:   DMLocalToGlobalBegin(da,local,INSERT_VALUES,global);
 70:   DMLocalToGlobalEnd(da,local,INSERT_VALUES,global);

 72:   VecView(global,viewer);

 74:   /* Send ghost points to local vectors */
 75:   DMGlobalToLocalBegin(da,global,INSERT_VALUES,locala);
 76:   DMGlobalToLocalEnd(da,global,INSERT_VALUES,locala);

 78:   /* Free memory */
 79:   PetscViewerDestroy(&viewer);
 80:   VecDestroy(&global);
 81:   VecDestroy(&local);
 82:   VecDestroy(&locala);
 83:   DMDestroy(&da);
 84:   PetscFinalize();
 85:   return 0;
 86: }