Actual source code: ex5.c
2: static char help[] = "Tests DAGetElements() and VecView() contour plotting for 2d DAs.\n\n";
4: #include petscda.h
8: int main(int argc,char **argv)
9: {
10: PetscInt M = 10,N = 8,m = PETSC_DECIDE,n = PETSC_DECIDE,ne,i;
11: const PetscInt *e;
13: PetscTruth flg = PETSC_FALSE;
14: DA da;
15: PetscViewer viewer;
16: Vec local,global;
17: PetscScalar value;
18: DAPeriodicType ptype = DA_NONPERIODIC;
19: DAStencilType stype = DA_STENCIL_BOX;
20: PetscScalar *lv;
22: PetscInitialize(&argc,&argv,(char*)0,help);
23: PetscViewerDrawOpen(PETSC_COMM_WORLD,0,"",300,0,300,300,&viewer);
25: /* Read options */
26: PetscOptionsGetInt(PETSC_NULL,"-M",&M,PETSC_NULL);
27: PetscOptionsGetInt(PETSC_NULL,"-N",&N,PETSC_NULL);
28: PetscOptionsGetInt(PETSC_NULL,"-m",&m,PETSC_NULL);
29: PetscOptionsGetInt(PETSC_NULL,"-n",&n,PETSC_NULL);
30: PetscOptionsGetTruth(PETSC_NULL,"-star_stencil",&flg,PETSC_NULL);
31: if (flg) stype = DA_STENCIL_STAR;
33: /* Create distributed array and get vectors */
34: DACreate2d(PETSC_COMM_WORLD,ptype,stype,M,N,m,n,1,1,PETSC_NULL,PETSC_NULL,&da);
35: DACreateGlobalVector(da,&global);
36: DACreateLocalVector(da,&local);
38: value = -3.0;
39: VecSet(global,value);
40: DAGlobalToLocalBegin(da,global,INSERT_VALUES,local);
41: DAGlobalToLocalEnd(da,global,INSERT_VALUES,local);
43: DAGetElements(da,&ne,&e);
44: VecGetArray(local,&lv);
45: for (i=0; i<ne; i++) {
46: PetscPrintf(PETSC_COMM_WORLD,"i %D e[3*i] %D %D %D\n",i,e[3*i],e[3*i+1],e[3*i+2]);
47: lv[e[3*i]] = i;
48: }
49: VecRestoreArray(local,&lv);
50: DARestoreElements(da,&ne,&e);
52: DALocalToGlobal(da,local,ADD_VALUES,global);
54: DAView(da,viewer);
55: VecView(global,viewer);
57: /* Free memory */
58: PetscViewerDestroy(viewer);
59: VecDestroy(local);
60: VecDestroy(global);
61: DADestroy(da);
62: PetscFinalize();
63: return 0;
64: }
65: