xref: /petsc/src/mat/tests/ex107.c (revision d5b43468fb8780a8feea140ccd6fa3e6a50411cc)
1 
2 static char help[] = "Test MatCreate() with MAT_STRUCTURE_ONLY .\n\n";
3 
4 #include <petscmat.h>
5 
6 int main(int argc, char **argv)
7 {
8   Mat         mat;
9   PetscInt    m = 7, n, i, j, rstart, rend;
10   PetscMPIInt size;
11   PetscScalar v;
12   PetscBool   struct_only = PETSC_TRUE;
13 
14   PetscFunctionBeginUser;
15   PetscCall(PetscInitialize(&argc, &argv, (char *)0, help));
16   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
17   PetscCheck(size == 1, PETSC_COMM_WORLD, PETSC_ERR_WRONG_MPI_SIZE, "This is a uniprocessor example only!");
18 
19   PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD, PETSC_VIEWER_ASCII_COMMON));
20   PetscCall(PetscOptionsGetInt(NULL, NULL, "-m", &m, NULL));
21   PetscCall(PetscOptionsGetBool(NULL, NULL, "-struct_only", &struct_only, NULL));
22   n = m;
23 
24   /* ------- Assemble matrix, test MatValid() --------- */
25   PetscCall(MatCreate(PETSC_COMM_WORLD, &mat));
26   PetscCall(MatSetSizes(mat, PETSC_DECIDE, PETSC_DECIDE, m, n));
27   PetscCall(MatSetFromOptions(mat));
28   if (struct_only) PetscCall(MatSetOption(mat, MAT_STRUCTURE_ONLY, PETSC_TRUE));
29   PetscCall(MatSetUp(mat));
30   PetscCall(MatGetOwnershipRange(mat, &rstart, &rend));
31   for (i = rstart; i < rend; i++) {
32     for (j = 0; j < n; j++) {
33       v = 10.0 * i + j;
34       PetscCall(MatSetValues(mat, 1, &i, 1, &j, &v, INSERT_VALUES));
35     }
36   }
37   PetscCall(MatAssemblyBegin(mat, MAT_FINAL_ASSEMBLY));
38   PetscCall(MatAssemblyEnd(mat, MAT_FINAL_ASSEMBLY));
39   PetscCall(MatView(mat, PETSC_VIEWER_STDOUT_WORLD));
40 
41   /* Free data structures */
42   PetscCall(MatDestroy(&mat));
43   PetscCall(PetscFinalize());
44   return 0;
45 }
46 
47 /*TEST
48 
49    test:
50       output_file: output/ex107.out
51 
52    test:
53       suffix: 2
54       args: -mat_type baij -mat_block_size 2 -m 10
55 
56 TEST*/
57