Actual source code: ex51.c
2: static char help[] = "Tests DMDAGlobalToNaturalAllCreate() using contour plotting for 2d DMDAs.\n\n";
4: #include <petscdm.h>
5: #include <petscdmda.h>
6: #include <petscdraw.h>
8: int main(int argc,char **argv)
9: {
10: PetscInt i,j,M = 10,N = 8,m = PETSC_DECIDE,n = PETSC_DECIDE;
11: PetscMPIInt rank;
12: PetscBool flg = PETSC_FALSE;
13: DM da;
14: PetscViewer viewer;
15: Vec localall,global;
16: PetscScalar value,*vlocal;
17: DMBoundaryType bx = DM_BOUNDARY_NONE,by = DM_BOUNDARY_NONE;
18: DMDAStencilType stype = DMDA_STENCIL_BOX;
19: VecScatter tolocalall,fromlocalall;
20: PetscInt start,end;
22: PetscInitialize(&argc,&argv,(char*)0,help);
23: PetscViewerDrawOpen(PETSC_COMM_WORLD,0,"",300,0,300,300,&viewer);
25: /* Read options */
26: PetscOptionsGetInt(NULL,NULL,"-M",&M,NULL);
27: PetscOptionsGetInt(NULL,NULL,"-N",&N,NULL);
28: PetscOptionsGetInt(NULL,NULL,"-m",&m,NULL);
29: PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
30: PetscOptionsGetBool(NULL,NULL,"-star_stencil",&flg,NULL);
31: if (flg) stype = DMDA_STENCIL_STAR;
33: /* Create distributed array and get vectors */
34: DMDACreate2d(PETSC_COMM_WORLD,bx,by,stype,M,N,m,n,1,1,NULL,NULL,&da);
35: DMSetFromOptions(da);
36: DMSetUp(da);
38: DMCreateGlobalVector(da,&global);
39: VecCreateSeq(PETSC_COMM_SELF,M*N,&localall);
41: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
42: VecGetOwnershipRange(global,&start,&end);
43: for (i=start; i<end; i++) {
44: value = 5.0*rank;
45: VecSetValues(global,1,&i,&value,INSERT_VALUES);
46: }
47: VecView(global,viewer);
49: /*
50: Create Scatter from global DMDA parallel vector to local vector that
51: contains all entries
52: */
53: DMDAGlobalToNaturalAllCreate(da,&tolocalall);
54: DMDANaturalAllToGlobalCreate(da,&fromlocalall);
56: VecScatterBegin(tolocalall,global,localall,INSERT_VALUES,SCATTER_FORWARD);
57: VecScatterEnd(tolocalall,global,localall,INSERT_VALUES,SCATTER_FORWARD);
59: VecGetArray(localall,&vlocal);
60: for (j=0; j<N; j++) {
61: for (i=0; i<M; i++) {
62: *vlocal++ += i + j*M;
63: }
64: }
65: VecRestoreArray(localall,&vlocal);
67: /* scatter back to global vector */
68: VecScatterBegin(fromlocalall,localall,global,INSERT_VALUES,SCATTER_FORWARD);
69: VecScatterEnd(fromlocalall,localall,global,INSERT_VALUES,SCATTER_FORWARD);
71: VecView(global,viewer);
73: /* Free memory */
74: VecScatterDestroy(&tolocalall);
75: VecScatterDestroy(&fromlocalall);
76: PetscViewerDestroy(&viewer);
77: VecDestroy(&localall);
78: VecDestroy(&global);
79: DMDestroy(&da);
80: PetscFinalize();
81: return 0;
82: }
84: /*TEST
86: build:
87: requires: !complex
89: test:
90: nsize: 3
92: TEST*/