1 2 static char help[] = "Tests MatDiagonalSet() 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; 10 PetscViewer fd; /* viewer */ 11 char file[PETSC_MAX_PATH_LEN]; /* input file name */ 12 PetscReal norm; 13 PetscBool flg; 14 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"); 20 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)); 33 34 /* Free data structures */ 35 PetscCall(MatDestroy(&A)); 36 PetscCall(VecDestroy(&x)); 37 PetscCall(PetscFinalize()); 38 return 0; 39 } 40 41 /*TEST 42 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 47 48 TEST*/ 49