Actual source code: ex65.c
2: static char help[] = "Saves a rectangular sparse matrix to disk.\n\n";
4: #include <petscmat.h>
6: int main(int argc, char **args)
7: {
8: Mat A;
9: PetscInt m = 100, n = 11, js[11], i, j, cnt;
10: PetscScalar values[11];
11: PetscViewer view;
13: PetscFunctionBeginUser;
14: PetscCall(PetscInitialize(&argc, &args, (char *)0, help));
15: PetscCall(MatCreateSeqAIJ(PETSC_COMM_WORLD, m, n, 20, 0, &A));
17: for (i = 0; i < n; i++) values[i] = (PetscReal)i;
19: for (i = 0; i < m; i++) {
20: cnt = 0;
21: if (i % 2) {
22: for (j = 0; j < n; j += 2) js[cnt++] = j;
23: } else {
24: ;
25: }
26: PetscCall(MatSetValues(A, 1, &i, cnt, js, values, INSERT_VALUES));
27: }
28: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
29: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
31: PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, "rect", FILE_MODE_WRITE, &view));
32: PetscCall(MatView(A, view));
33: PetscCall(PetscViewerDestroy(&view));
35: PetscCall(MatDestroy(&A));
37: PetscCall(PetscFinalize());
38: return 0;
39: }
41: /*TEST
43: test:
45: TEST*/