1 static char help[] = "Check the difference of the two matrices \n\ 2 Reads PETSc matrix A and B, then check B=A-B \n\ 3 Input parameters include\n\ 4 -fA <input_file> -fB <input_file> \n\n"; 5 6 #include <petscmat.h> 7 8 int main(int argc, char **args) 9 { 10 Mat A, B; 11 PetscViewer fd; 12 char file[2][PETSC_MAX_PATH_LEN]; 13 PetscBool flg; 14 PetscMPIInt size; 15 PetscInt ma, na, mb, nb; 16 17 PetscFunctionBeginUser; 18 PetscCall(PetscInitialize(&argc, &args, (char *)0, help)); 19 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size)); 20 PetscCheck(size == 1, PETSC_COMM_WORLD, PETSC_ERR_WRONG_MPI_SIZE, "This is a uniprocessor example only!"); 21 22 /* read the two matrices, A and B */ 23 PetscCall(PetscOptionsGetString(NULL, NULL, "-fA", file[0], sizeof(file[0]), &flg)); 24 PetscCheck(flg, PETSC_COMM_WORLD, PETSC_ERR_USER, "Must indicate binary file with the -fA options"); 25 PetscCall(PetscOptionsGetString(NULL, NULL, "-fB", file[1], sizeof(file[1]), &flg)); 26 PetscCheck(flg, PETSC_COMM_WORLD, PETSC_ERR_USER, "Must indicate binary file with the -fP options"); 27 28 /* Load matrices */ 29 PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, file[0], FILE_MODE_READ, &fd)); 30 PetscCall(MatCreate(PETSC_COMM_WORLD, &A)); 31 PetscCall(MatLoad(A, fd)); 32 PetscCall(PetscViewerDestroy(&fd)); 33 printf("\n A:\n"); 34 printf("----------------------\n"); 35 PetscCall(MatView(A, PETSC_VIEWER_STDOUT_WORLD)); 36 PetscCall(MatGetSize(A, &ma, &na)); 37 38 PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, file[1], FILE_MODE_READ, &fd)); 39 PetscCall(MatCreate(PETSC_COMM_WORLD, &B)); 40 PetscCall(MatLoad(B, fd)); 41 PetscCall(PetscViewerDestroy(&fd)); 42 printf("\n B:\n"); 43 printf("----------------------\n"); 44 PetscCall(MatView(B, PETSC_VIEWER_STDOUT_WORLD)); 45 PetscCall(MatGetSize(B, &mb, &nb)); 46 47 /* Compute B = -A + B */ 48 PetscCheck(ma == mb && na == nb, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "nonconforming matrix size"); 49 PetscCall(MatAXPY(B, -1.0, A, DIFFERENT_NONZERO_PATTERN)); 50 printf("\n B - A:\n"); 51 printf("----------------------\n"); 52 PetscCall(MatView(B, PETSC_VIEWER_STDOUT_WORLD)); 53 54 PetscCall(MatDestroy(&B)); 55 PetscCall(MatDestroy(&A)); 56 PetscCall(PetscFinalize()); 57 return 0; 58 } 59