1 static char help[] = "Saves a dense matrix in a dense format (binary).\n\n";
2
3 #include <petscmat.h>
4
main(int argc,char ** args)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;
12
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));
19
20 /* PART 1: Generate matrix, then write it in binary format */
21
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 }
39
40 /*TEST
41
42 test:
43 output_file: output/empty.out
44
45 TEST*/
46