xref: /petsc/src/dm/tests/ex14.c (revision c4762a1b19cd2af06abeed90e8f9d34fb975dd94)
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   PetscErrorCode ierr;
16   DM             da;
17   Vec            local,global,natural;
18   PetscScalar    value;
19   PetscViewer    bviewer;
20 
21   ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
22   ierr = PetscOptionsGetInt(NULL,NULL,"-M",&M,NULL);CHKERRQ(ierr);
23   ierr = PetscOptionsGetInt(NULL,NULL,"-N",&N,NULL);CHKERRQ(ierr);
24   ierr = PetscOptionsGetInt(NULL,NULL,"-m",&m,NULL);CHKERRQ(ierr);
25   ierr = PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);CHKERRQ(ierr);
26   ierr = PetscOptionsGetInt(NULL,NULL,"-dof",&dof,NULL);CHKERRQ(ierr);
27 
28   /* Create distributed array and get vectors */
29   ierr = DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,M,N,m,n,dof,1,NULL,NULL,&da);CHKERRQ(ierr);
30   ierr = DMSetFromOptions(da);CHKERRQ(ierr);
31   ierr = DMSetUp(da);CHKERRQ(ierr);
32   ierr = DMCreateGlobalVector(da,&global);CHKERRQ(ierr);
33   ierr = DMCreateLocalVector(da,&local);CHKERRQ(ierr);
34 
35   value = -3.0;
36   ierr  = VecSet(global,value);CHKERRQ(ierr);
37   ierr  = DMGlobalToLocalBegin(da,global,INSERT_VALUES,local);CHKERRQ(ierr);
38   ierr  = DMGlobalToLocalEnd(da,global,INSERT_VALUES,local);CHKERRQ(ierr);
39 
40   ierr  = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
41   value = rank+1;
42   ierr  = VecScale(local,value);CHKERRQ(ierr);
43   ierr  = DMLocalToGlobalBegin(da,local,ADD_VALUES,global);CHKERRQ(ierr);
44   ierr  = DMLocalToGlobalEnd(da,local,ADD_VALUES,global);CHKERRQ(ierr);
45 
46   ierr = DMDACreateNaturalVector(da,&natural);CHKERRQ(ierr);
47   ierr = DMDAGlobalToNaturalBegin(da,global,INSERT_VALUES,natural);CHKERRQ(ierr);
48   ierr = DMDAGlobalToNaturalEnd(da,global,INSERT_VALUES,natural);CHKERRQ(ierr);
49 
50   ierr = DMDASetFieldName(da,0,"First field");CHKERRQ(ierr);
51   /*  ierr = VecView(global,PETSC_VIEWER_DRAW_WORLD);CHKERRQ(ierr); */
52 
53   ierr = PetscViewerBinaryOpen(PETSC_COMM_WORLD,"daoutput",FILE_MODE_WRITE,&bviewer);CHKERRQ(ierr);
54   ierr = DMView(da,bviewer);CHKERRQ(ierr);
55   ierr = VecView(global,bviewer);CHKERRQ(ierr);
56   ierr = PetscViewerDestroy(&bviewer);CHKERRQ(ierr);
57 
58   /* Free memory */
59   ierr = VecDestroy(&local);CHKERRQ(ierr);
60   ierr = VecDestroy(&global);CHKERRQ(ierr);
61   ierr = VecDestroy(&natural);CHKERRQ(ierr);
62   ierr = DMDestroy(&da);CHKERRQ(ierr);
63   ierr = PetscFinalize();
64   return ierr;
65 }
66 
67