xref: /petsc/src/dm/tests/ex14.c (revision b122ec5aa1bd4469eb4e0673542fb7de3f411254)
1 
2 static char help[] = "Tests saving DMDA vectors to files.\n\n";
3 
4 /*
5     ex13.c reads in the DMDA and vector written by this program.
6 */
7 
8 #include <petscdm.h>
9 #include <petscdmda.h>
10 
11 int main(int argc,char **argv)
12 {
13   PetscMPIInt    rank;
14   PetscInt       M = 10,N = 8,m = PETSC_DECIDE,n = PETSC_DECIDE, dof = 1;
15   DM             da;
16   Vec            local,global,natural;
17   PetscScalar    value;
18   PetscViewer    bviewer;
19 
20   CHKERRQ(PetscInitialize(&argc,&argv,(char*)0,help));
21   CHKERRQ(PetscOptionsGetInt(NULL,NULL,"-M",&M,NULL));
22   CHKERRQ(PetscOptionsGetInt(NULL,NULL,"-N",&N,NULL));
23   CHKERRQ(PetscOptionsGetInt(NULL,NULL,"-m",&m,NULL));
24   CHKERRQ(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
25   CHKERRQ(PetscOptionsGetInt(NULL,NULL,"-dof",&dof,NULL));
26 
27   /* Create distributed array and get vectors */
28   CHKERRQ(DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,M,N,m,n,dof,1,NULL,NULL,&da));
29   CHKERRQ(DMSetFromOptions(da));
30   CHKERRQ(DMSetUp(da));
31   CHKERRQ(DMCreateGlobalVector(da,&global));
32   CHKERRQ(DMCreateLocalVector(da,&local));
33 
34   value = -3.0;
35   CHKERRQ(VecSet(global,value));
36   CHKERRQ(DMGlobalToLocalBegin(da,global,INSERT_VALUES,local));
37   CHKERRQ(DMGlobalToLocalEnd(da,global,INSERT_VALUES,local));
38 
39   CHKERRMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank));
40   value = rank+1;
41   CHKERRQ(VecScale(local,value));
42   CHKERRQ(DMLocalToGlobalBegin(da,local,ADD_VALUES,global));
43   CHKERRQ(DMLocalToGlobalEnd(da,local,ADD_VALUES,global));
44 
45   CHKERRQ(DMDACreateNaturalVector(da,&natural));
46   CHKERRQ(DMDAGlobalToNaturalBegin(da,global,INSERT_VALUES,natural));
47   CHKERRQ(DMDAGlobalToNaturalEnd(da,global,INSERT_VALUES,natural));
48 
49   CHKERRQ(DMDASetFieldName(da,0,"First field"));
50   /*  CHKERRQ(VecView(global,PETSC_VIEWER_DRAW_WORLD)); */
51 
52   CHKERRQ(PetscViewerBinaryOpen(PETSC_COMM_WORLD,"daoutput",FILE_MODE_WRITE,&bviewer));
53   CHKERRQ(DMView(da,bviewer));
54   CHKERRQ(VecView(global,bviewer));
55   CHKERRQ(PetscViewerDestroy(&bviewer));
56 
57   /* Free memory */
58   CHKERRQ(VecDestroy(&local));
59   CHKERRQ(VecDestroy(&global));
60   CHKERRQ(VecDestroy(&natural));
61   CHKERRQ(DMDestroy(&da));
62   CHKERRQ(PetscFinalize());
63   return 0;
64 }
65