Actual source code: ex12.c
2: static char help[] = "Tests the use of MatZeroRows() for parallel matrices.\n\
3: This example also tests the use of MatDuplicate() for both MPIAIJ and MPIBAIJ matrices";
5: #include <petscmat.h>
7: extern PetscErrorCode TestMatZeroRows_Basic(Mat, IS, PetscScalar);
8: extern PetscErrorCode TestMatZeroRows_with_no_allocation(Mat, IS, PetscScalar);
10: int main(int argc, char **args)
11: {
12: Mat A;
13: PetscInt i, j, m = 3, n, Ii, J, Imax;
14: PetscMPIInt rank, size;
15: PetscScalar v, diag = -4.0;
16: IS is;
19: PetscInitialize(&argc, &args, (char *)0, help);
20: MPI_Comm_rank(PETSC_COMM_WORLD, &rank);
21: MPI_Comm_size(PETSC_COMM_WORLD, &size);
22: n = 2 * size;
24: /* create A Square matrix for the five point stencil,YET AGAIN*/
25: MatCreate(PETSC_COMM_WORLD, &A);
26: MatSetSizes(A, PETSC_DECIDE, PETSC_DECIDE, m * n, m * n);
27: MatSetFromOptions(A);
28: MatSetUp(A);
29: for (i = 0; i < m; i++) {
30: for (j = 2 * rank; j < 2 * rank + 2; j++) {
31: v = -1.0;
32: Ii = j + n * i;
33: if (i > 0) {
34: J = Ii - n;
35: MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES);
36: }
37: if (i < m - 1) {
38: J = Ii + n;
39: MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES);
40: }
41: if (j > 0) {
42: J = Ii - 1;
43: MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES);
44: }
45: if (j < n - 1) {
46: J = Ii + 1;
47: MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES);
48: }
49: v = 4.0;
50: MatSetValues(A, 1, &Ii, 1, &Ii, &v, INSERT_VALUES);
51: }
52: }
53: MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY);
54: MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY);
56: /* Create AN IS required by MatZeroRows() */
57: Imax = n * rank;
58: if (Imax >= n * m - m - 1) Imax = m * n - m - 1;
59: ISCreateStride(PETSC_COMM_SELF, m, Imax, 1, &is);
61: TestMatZeroRows_Basic(A, is, 0.0);
62: TestMatZeroRows_Basic(A, is, diag);
64: TestMatZeroRows_with_no_allocation(A, is, 0.0);
65: TestMatZeroRows_with_no_allocation(A, is, diag);
67: MatDestroy(&A);
69: /* Now Create a rectangular matrix with five point stencil (app)
70: n+size is used so that this dimension is always divisible by size.
71: This way, we can always use bs = size for any number of procs */
72: MatCreate(PETSC_COMM_WORLD, &A);
73: MatSetSizes(A, PETSC_DECIDE, PETSC_DECIDE, m * n, m * (n + size));
74: MatSetFromOptions(A);
75: MatSetUp(A);
76: for (i = 0; i < m; i++) {
77: for (j = 2 * rank; j < 2 * rank + 2; j++) {
78: v = -1.0;
79: Ii = j + n * i;
80: if (i > 0) {
81: J = Ii - n;
82: MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES);
83: }
84: if (i < m - 1) {
85: J = Ii + n;
86: MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES);
87: }
88: if (j > 0) {
89: J = Ii - 1;
90: MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES);
91: }
92: if (j < n + size - 1) {
93: J = Ii + 1;
94: MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES);
95: }
96: v = 4.0;
97: MatSetValues(A, 1, &Ii, 1, &Ii, &v, INSERT_VALUES);
98: }
99: }
100: MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY);
101: MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY);
103: TestMatZeroRows_Basic(A, is, 0.0);
104: TestMatZeroRows_Basic(A, is, diag);
106: MatDestroy(&A);
107: ISDestroy(&is);
108: PetscFinalize();
109: return 0;
110: }
112: PetscErrorCode TestMatZeroRows_Basic(Mat A, IS is, PetscScalar diag)
113: {
114: Mat B;
115: PetscBool keepnonzeropattern;
117: /* Now copy A into B, and test it with MatZeroRows() */
118: MatDuplicate(A, MAT_COPY_VALUES, &B);
120: PetscOptionsHasName(NULL, NULL, "-keep_nonzero_pattern", &keepnonzeropattern);
121: if (keepnonzeropattern) MatSetOption(B, MAT_KEEP_NONZERO_PATTERN, PETSC_TRUE);
123: MatZeroRowsIS(B, is, diag, 0, 0);
124: MatView(B, PETSC_VIEWER_STDOUT_WORLD);
125: MatDestroy(&B);
126: return 0;
127: }
129: PetscErrorCode TestMatZeroRows_with_no_allocation(Mat A, IS is, PetscScalar diag)
130: {
131: Mat B;
133: /* Now copy A into B, and test it with MatZeroRows() */
134: MatDuplicate(A, MAT_COPY_VALUES, &B);
135: /* Set this flag after assembly. This way, it affects only MatZeroRows() */
136: MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_TRUE);
138: MatZeroRowsIS(B, is, diag, 0, 0);
139: MatView(B, PETSC_VIEWER_STDOUT_WORLD);
140: MatDestroy(&B);
141: return 0;
142: }
144: /*TEST
146: test:
147: nsize: 2
148: filter: grep -v " MPI process"
150: test:
151: suffix: 2
152: nsize: 3
153: args: -mat_type mpibaij -mat_block_size 3
154: filter: grep -v " MPI process"
156: test:
157: suffix: 3
158: nsize: 3
159: args: -mat_type mpiaij -keep_nonzero_pattern
160: filter: grep -v " MPI process"
162: test:
163: suffix: 4
164: nsize: 3
165: args: -keep_nonzero_pattern -mat_type mpibaij -mat_block_size 3
166: filter: grep -v " MPI process"
168: TEST*/