xref: /petsc/src/mat/tests/ex87.c (revision ffa8c5705e8ab2cf85ee1d14dbe507a6e2eb5283)
1 
2 static char help[] = "Tests MatCreateSubMatrices() for SBAIJ matrices\n\n";
3 
4 #include <petscmat.h>
5 
6 int main(int argc,char **args)
7 {
8   Mat            BAIJ,SBAIJ,*subBAIJ,*subSBAIJ;
9   PetscViewer    viewer;
10   char           file[PETSC_MAX_PATH_LEN];
11   PetscBool      flg;
12   PetscInt       n = 2,issize,M,N;
13   PetscMPIInt    rank;
14   IS             isrow,iscol,irow[n],icol[n];
15 
16   PetscCall(PetscInitialize(&argc,&args,(char*)0,help));
17   PetscCall(PetscOptionsGetString(NULL,NULL,"-f",file,sizeof(file),&flg));
18   PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD,file,FILE_MODE_READ,&viewer));
19 
20   PetscCall(MatCreate(PETSC_COMM_WORLD,&BAIJ));
21   PetscCall(MatSetType(BAIJ,MATMPIBAIJ));
22   PetscCall(MatLoad(BAIJ,viewer));
23   PetscCall(PetscViewerDestroy(&viewer));
24 
25   PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD,file,FILE_MODE_READ,&viewer));
26   PetscCall(MatCreate(PETSC_COMM_WORLD,&SBAIJ));
27   PetscCall(MatSetType(SBAIJ,MATMPISBAIJ));
28   PetscCall(MatLoad(SBAIJ,viewer));
29   PetscCall(PetscViewerDestroy(&viewer));
30 
31   PetscCall(MatGetSize(BAIJ,&M,&N));
32   issize = M/4;
33   PetscCall(ISCreateStride(PETSC_COMM_SELF,issize,0,1,&isrow));
34   irow[0] = irow[1] = isrow;
35   issize = N/2;
36   PetscCall(ISCreateStride(PETSC_COMM_SELF,issize,0,1,&iscol));
37   icol[0] = icol[1] = iscol;
38   PetscCall(MatCreateSubMatrices(BAIJ,n,irow,icol,MAT_INITIAL_MATRIX,&subBAIJ));
39   PetscCall(MatCreateSubMatrices(BAIJ,n,irow,icol,MAT_REUSE_MATRIX,&subBAIJ));
40 
41   /* irow and icol must be same for SBAIJ matrices! */
42   icol[0] = icol[1] = isrow;
43   PetscCall(MatCreateSubMatrices(SBAIJ,n,irow,icol,MAT_INITIAL_MATRIX,&subSBAIJ));
44   PetscCall(MatCreateSubMatrices(SBAIJ,n,irow,icol,MAT_REUSE_MATRIX,&subSBAIJ));
45 
46   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank));
47   if (rank == 0) {
48     PetscCall(MatView(subBAIJ[0],PETSC_VIEWER_STDOUT_SELF));
49     PetscCall(MatView(subSBAIJ[0],PETSC_VIEWER_STDOUT_SELF));
50   }
51 
52   /* Free data structures */
53   PetscCall(ISDestroy(&isrow));
54   PetscCall(ISDestroy(&iscol));
55   PetscCall(MatDestroySubMatrices(n,&subBAIJ));
56   PetscCall(MatDestroySubMatrices(n,&subSBAIJ));
57   PetscCall(MatDestroy(&BAIJ));
58   PetscCall(MatDestroy(&SBAIJ));
59 
60   PetscCall(PetscFinalize());
61   return 0;
62 }
63