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;
16: PetscInitialize(&argc, &args, (char *)0, help);
17: /* Determine file from which we read the matrix A */
18: PetscOptionsGetString(NULL, NULL, "-f", file, sizeof(file), &flg);
21: /* Load matrix A */
22: PetscViewerBinaryOpen(PETSC_COMM_WORLD, file, FILE_MODE_READ, &fd);
23: MatCreate(PETSC_COMM_WORLD, &A);
24: MatLoad(A, fd);
25: PetscViewerDestroy(&fd);
26: MatCreateVecs(A, &x, NULL);
27: MatGetDiagonal(A, x);
28: VecScale(x, -1.0);
29: MatDiagonalSet(A, x, ADD_VALUES);
30: MatGetDiagonal(A, x);
31: VecNorm(x, NORM_2, &norm);
32: PetscPrintf(PETSC_COMM_WORLD, "Norm %g\n", (double)norm);
34: /* Free data structures */
35: MatDestroy(&A);
36: VecDestroy(&x);
37: 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*/