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*/