xref: /petsc/src/mat/tests/ex131.c (revision ebead697dbf761eb322f829370bbe90b3bd93fa3)
1 
2 static char help[] = "Tests MatMult() on MatLoad() matrix \n\n";
3 
4 #include <petscmat.h>
5 
6 int main(int argc,char **args)
7 {
8   Mat            A;
9   Vec            x,b;
10   PetscViewer    fd;              /* viewer */
11   char           file[PETSC_MAX_PATH_LEN]; /* input file name */
12   PetscBool      flg;
13 
14   PetscFunctionBeginUser;
15   PetscCall(PetscInitialize(&argc,&args,(char*)0,help));
16   /* Determine file from which we read the matrix A */
17   PetscCall(PetscOptionsGetString(NULL,NULL,"-f",file,sizeof(file),&flg));
18   PetscCheck(flg,PETSC_COMM_WORLD,PETSC_ERR_USER,"Must indicate binary file with the -f option");
19 
20   /* Load matrix A */
21   PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD,file,FILE_MODE_READ,&fd));
22   PetscCall(MatCreate(PETSC_COMM_WORLD,&A));
23   PetscCall(MatLoad(A,fd));
24   flg  = PETSC_FALSE;
25   PetscCall(VecCreate(PETSC_COMM_WORLD,&x));
26   PetscCall(PetscOptionsGetString(NULL,NULL,"-vec",file,sizeof(file),&flg));
27   if (flg) {
28     if (file[0] == '0') {
29       PetscInt    m;
30       PetscScalar one = 1.0;
31       PetscCall(PetscInfo(0,"Using vector of ones for RHS\n"));
32       PetscCall(MatGetLocalSize(A,&m,NULL));
33       PetscCall(VecSetSizes(x,m,PETSC_DECIDE));
34       PetscCall(VecSetFromOptions(x));
35       PetscCall(VecSet(x,one));
36     }
37   } else {
38     PetscCall(VecLoad(x,fd));
39     PetscCall(PetscViewerDestroy(&fd));
40   }
41   PetscCall(VecDuplicate(x,&b));
42   PetscCall(MatMult(A,x,b));
43 
44   /* Print (for testing only) */
45   PetscCall(MatView(A,0));
46   PetscCall(VecView(b,0));
47   /* Free data structures */
48   PetscCall(MatDestroy(&A));
49   PetscCall(VecDestroy(&x));
50   PetscCall(VecDestroy(&b));
51   PetscCall(PetscFinalize());
52   return 0;
53 }
54