Actual source code: ex21.c
1: static char help[] = "Tests converting a parallel AIJ formatted matrix to the parallel Row format.\n\
2: This also tests MatGetRow() and MatRestoreRow() for the parallel case.\n\n";
4: #include <petscmat.h>
6: int main(int argc, char **args)
7: {
8: Mat C, A;
9: PetscInt i, j, m = 3, n = 2, Ii, J, rstart, rend, nz;
10: PetscMPIInt rank, size;
11: const PetscInt *idx;
12: PetscScalar v;
13: const PetscScalar *values;
15: PetscFunctionBeginUser;
16: PetscCall(PetscInitialize(&argc, &args, (char *)0, help));
17: PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
18: PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
19: n = 2 * size;
21: /* create the matrix for the five point stencil, YET AGAIN*/
22: PetscCall(MatCreate(PETSC_COMM_WORLD, &C));
23: PetscCall(MatSetSizes(C, PETSC_DECIDE, PETSC_DECIDE, m * n, m * n));
24: PetscCall(MatSetFromOptions(C));
25: PetscCall(MatMPIAIJSetPreallocation(C, 5, NULL, 5, NULL));
26: PetscCall(MatSeqAIJSetPreallocation(C, 5, NULL));
27: for (i = 0; i < m; i++) {
28: for (j = 2 * rank; j < 2 * rank + 2; j++) {
29: v = -1.0;
30: Ii = j + n * i;
31: if (i > 0) {
32: J = Ii - n;
33: PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES));
34: }
35: if (i < m - 1) {
36: J = Ii + n;
37: PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES));
38: }
39: if (j > 0) {
40: J = Ii - 1;
41: PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES));
42: }
43: if (j < n - 1) {
44: J = Ii + 1;
45: PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES));
46: }
47: v = 4.0;
48: PetscCall(MatSetValues(C, 1, &Ii, 1, &Ii, &v, INSERT_VALUES));
49: }
50: }
51: PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
52: PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
53: PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD, PETSC_VIEWER_ASCII_INFO));
54: PetscCall(MatView(C, PETSC_VIEWER_STDOUT_WORLD));
55: PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD));
56: PetscCall(MatView(C, PETSC_VIEWER_STDOUT_WORLD));
58: PetscCall(MatGetOwnershipRange(C, &rstart, &rend));
59: for (i = rstart; i < rend; i++) {
60: PetscCall(MatGetRow(C, i, &nz, &idx, &values));
61: PetscCall(PetscSynchronizedFPrintf(PETSC_COMM_WORLD, stdout, "[%d] get row %" PetscInt_FMT ": ", rank, i));
62: for (j = 0; j < nz; j++) PetscCall(PetscSynchronizedFPrintf(PETSC_COMM_WORLD, stdout, "%" PetscInt_FMT " %g ", idx[j], (double)PetscRealPart(values[j])));
63: PetscCall(PetscSynchronizedFPrintf(PETSC_COMM_WORLD, stdout, "\n"));
64: PetscCall(MatRestoreRow(C, i, &nz, &idx, &values));
65: }
66: PetscCall(PetscSynchronizedFlush(PETSC_COMM_WORLD, stdout));
68: PetscCall(MatConvert(C, MATSAME, MAT_INITIAL_MATRIX, &A));
69: PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD, PETSC_VIEWER_ASCII_INFO));
70: PetscCall(MatView(A, PETSC_VIEWER_STDOUT_WORLD));
71: PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD));
72: PetscCall(MatView(A, PETSC_VIEWER_STDOUT_WORLD));
74: PetscCall(MatDestroy(&A));
75: PetscCall(MatDestroy(&C));
76: PetscCall(PetscFinalize());
77: return 0;
78: }
80: /*TEST
82: test:
83: args: -mat_type seqaij
85: TEST*/