xref: /petsc/src/mat/tests/ex131.c (revision 732aec7a18f2199fb53bb9a2f3aef439a834ce31)
1 static char help[] = "Tests MatMult() on MatLoad() matrix \n\n";
2 
3 #include <petscmat.h>
4 
main(int argc,char ** args)5 int main(int argc, char **args)
6 {
7   Mat         A;
8   Vec         x, b;
9   PetscViewer fd;                       /* viewer */
10   char        file[PETSC_MAX_PATH_LEN]; /* input file name */
11   PetscBool   flg;
12 
13   PetscFunctionBeginUser;
14   PetscCall(PetscInitialize(&argc, &args, NULL, help));
15   /* Determine file from which we read the matrix A */
16   PetscCall(PetscOptionsGetString(NULL, NULL, "-f", file, sizeof(file), &flg));
17   PetscCheck(flg, PETSC_COMM_WORLD, PETSC_ERR_USER, "Must indicate binary file with the -f option");
18 
19   /* Load matrix A */
20   PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, file, FILE_MODE_READ, &fd));
21   PetscCall(MatCreate(PETSC_COMM_WORLD, &A));
22   PetscCall(MatLoad(A, fd));
23   flg = PETSC_FALSE;
24   PetscCall(VecCreate(PETSC_COMM_WORLD, &x));
25   PetscCall(PetscOptionsGetString(NULL, NULL, "-vec", file, sizeof(file), &flg));
26   if (flg) {
27     if (file[0] == '0') {
28       PetscInt    m;
29       PetscScalar one = 1.0;
30       PetscCall(PetscInfo(0, "Using vector of ones for RHS\n"));
31       PetscCall(MatGetLocalSize(A, &m, NULL));
32       PetscCall(VecSetSizes(x, m, PETSC_DECIDE));
33       PetscCall(VecSetFromOptions(x));
34       PetscCall(VecSet(x, one));
35     }
36   } else {
37     PetscCall(VecLoad(x, fd));
38     PetscCall(PetscViewerDestroy(&fd));
39   }
40   PetscCall(VecDuplicate(x, &b));
41   PetscCall(MatMult(A, x, b));
42 
43   /* Print (for testing only) */
44   PetscCall(MatView(A, 0));
45   PetscCall(VecView(b, 0));
46   /* Free data structures */
47   PetscCall(MatDestroy(&A));
48   PetscCall(VecDestroy(&x));
49   PetscCall(VecDestroy(&b));
50   PetscCall(PetscFinalize());
51   return 0;
52 }
53