Actual source code: ex43.c
1: static char help[] = "Saves a dense matrix in a dense format (binary).\n\n";
3: #include <petscmat.h>
5: int main(int argc, char **args)
6: {
7: Mat C;
8: PetscScalar v;
9: PetscInt i, j, m = 4, n = 4;
10: PetscMPIInt rank, size;
11: PetscViewer viewer;
13: PetscFunctionBeginUser;
14: PetscCall(PetscInitialize(&argc, &args, NULL, help));
15: PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
16: PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
17: PetscCall(PetscOptionsGetInt(NULL, NULL, "-m", &m, NULL));
18: PetscCall(PetscOptionsGetInt(NULL, NULL, "-n", &n, NULL));
20: /* PART 1: Generate matrix, then write it in binary format */
22: /* Generate matrix */
23: PetscCall(MatCreateSeqDense(PETSC_COMM_WORLD, m, n, NULL, &C));
24: for (i = 0; i < m; i++) {
25: for (j = 0; j < n; j++) {
26: v = i * m + j;
27: PetscCall(MatSetValues(C, 1, &i, 1, &j, &v, INSERT_VALUES));
28: }
29: }
30: PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
31: PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
32: PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, "matrix.dat", FILE_MODE_WRITE, &viewer));
33: PetscCall(MatView(C, viewer));
34: PetscCall(PetscViewerDestroy(&viewer));
35: PetscCall(MatDestroy(&C));
36: PetscCall(PetscFinalize());
37: return 0;
38: }
40: /*TEST
42: test:
44: TEST*/