xref: /petsc/src/dm/tests/ex5.c (revision ebead697dbf761eb322f829370bbe90b3bd93fa3) !
1 /*
2   Test DMCreateMatrix() for structure_only
3 */
4 
5 #include <petscdmda.h>
6 
7 int main(int argc, char *argv[])
8 {
9   PetscInt       nx=6,ny=6,nz=6,dim=1,dof=2;
10   DM             da;
11   Mat            A;
12   PetscBool      struct_only=PETSC_TRUE;
13 
14   PetscFunctionBeginUser;
15   PetscCall(PetscInitialize(&argc,&argv,NULL,NULL));
16   PetscCall(PetscOptionsGetInt(NULL,NULL,"-dim",&dim,NULL));
17   PetscCall(PetscOptionsGetInt(NULL,NULL,"-dof",&dof,NULL));
18   switch (dim) {
19   case 1:
20     PetscCall(DMDACreate1d(PETSC_COMM_WORLD,DM_BOUNDARY_NONE,nx,dof,1,NULL,&da));
21     break;
22   case 2:
23     PetscCall(DMDACreate2d(PETSC_COMM_WORLD,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_STAR,nx,ny,PETSC_DECIDE,PETSC_DECIDE,dof,1,NULL,NULL,&da));
24     break;
25   default:
26     PetscCall(DMDACreate3d(PETSC_COMM_WORLD,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,nx,ny,nz,
27                            PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE,dof,2,NULL,NULL,NULL,&da));
28   }
29 
30   PetscCall(DMSetFromOptions(da));
31   PetscCall(DMSetUp(da));
32   PetscCall(DMView(da,PETSC_VIEWER_STDOUT_WORLD));
33 
34   PetscCall(PetscOptionsGetBool(NULL,NULL,"-struct_only",&struct_only,NULL));
35   PetscCall(DMSetMatrixStructureOnly(da,struct_only));
36   PetscCall(DMCreateMatrix(da,&A));
37   /* Set da->structure_only to default PETSC_FALSE in case da is being used to create new matrices */
38   PetscCall(DMSetMatrixStructureOnly(da,PETSC_FALSE));
39 
40   PetscCall(MatView(A,PETSC_VIEWER_STDOUT_WORLD));
41   PetscCall(MatDestroy(&A));
42   PetscCall(DMDestroy(&da));
43   PetscCall(PetscFinalize());
44   return 0;
45 }
46 
47 /*TEST
48 
49    test:
50 
51    test:
52       suffix: 2
53       args: -dm_mat_type baij -dim 2
54 
55 TEST*/
56