Actual source code: ex171.c
2: static char help[] = "Tests MatDiagonalSet() on MatLoad() matrix \n\n";
4: #include <petscmat.h>
6: int main(int argc, char **args)
7: {
8: Mat A;
9: Vec x;
10: PetscViewer fd; /* viewer */
11: char file[PETSC_MAX_PATH_LEN]; /* input file name */
12: PetscReal norm;
13: PetscBool flg;
15: PetscFunctionBeginUser;
16: PetscCall(PetscInitialize(&argc, &args, (char *)0, help));
17: /* Determine file from which we read the matrix A */
18: PetscCall(PetscOptionsGetString(NULL, NULL, "-f", file, sizeof(file), &flg));
19: PetscCheck(flg, PETSC_COMM_WORLD, PETSC_ERR_USER, "Must indicate binary file with the -f option");
21: /* Load matrix A */
22: PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, file, FILE_MODE_READ, &fd));
23: PetscCall(MatCreate(PETSC_COMM_WORLD, &A));
24: PetscCall(MatLoad(A, fd));
25: PetscCall(PetscViewerDestroy(&fd));
26: PetscCall(MatCreateVecs(A, &x, NULL));
27: PetscCall(MatGetDiagonal(A, x));
28: PetscCall(VecScale(x, -1.0));
29: PetscCall(MatDiagonalSet(A, x, ADD_VALUES));
30: PetscCall(MatGetDiagonal(A, x));
31: PetscCall(VecNorm(x, NORM_2, &norm));
32: PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Norm %g\n", (double)norm));
34: /* Free data structures */
35: PetscCall(MatDestroy(&A));
36: PetscCall(VecDestroy(&x));
37: PetscCall(PetscFinalize());
38: return 0;
39: }
41: /*TEST
43: test:
44: nsize: 4
45: requires: datafilespath !complex double !defined(PETSC_USE_64BIT_INDICES)
46: args: -f ${wPETSC_DIR}/share/petsc/datafiles/matrices/ns-real-int32-float64 -malloc_dump
48: TEST*/