Actual source code: ex171.c

  1: static char help[] = "Tests MatDiagonalSet() on MatLoad() matrix \n\n";

  3: #include <petscmat.h>

  5: int main(int argc, char **args)
  6: {
  7:   Mat         A;
  8:   Vec         x;
  9:   PetscViewer fd;                       /* viewer */
 10:   char        file[PETSC_MAX_PATH_LEN]; /* input file name */
 11:   PetscReal   norm;
 12:   PetscBool   flg;

 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");

 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:   PetscCall(PetscViewerDestroy(&fd));
 25:   PetscCall(MatCreateVecs(A, &x, NULL));
 26:   PetscCall(MatGetDiagonal(A, x));
 27:   PetscCall(VecScale(x, -1.0));
 28:   PetscCall(MatDiagonalSet(A, x, ADD_VALUES));
 29:   PetscCall(MatGetDiagonal(A, x));
 30:   PetscCall(VecNorm(x, NORM_2, &norm));
 31:   PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Norm %g\n", (double)norm));

 33:   /* Free data structures */
 34:   PetscCall(MatDestroy(&A));
 35:   PetscCall(VecDestroy(&x));
 36:   PetscCall(PetscFinalize());
 37:   return 0;
 38: }

 40: /*TEST

 42:    test:
 43:       nsize: 4
 44:       requires: datafilespath !complex double !defined(PETSC_USE_64BIT_INDICES)
 45:       args: -f ${wPETSC_DIR}/share/petsc/datafiles/matrices/ns-real-int32-float64 -malloc_dump

 47: TEST*/