xref: /petsc/src/mat/tests/ex12.c (revision a69119a591a03a9d906b29c0a4e9802e4d7c9795)
1 
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";
4 
5 #include <petscmat.h>
6 
7 extern PetscErrorCode TestMatZeroRows_Basic(Mat, IS, PetscScalar);
8 extern PetscErrorCode TestMatZeroRows_with_no_allocation(Mat, IS, PetscScalar);
9 
10 int main(int argc, char **args) {
11   Mat         A;
12   PetscInt    i, j, m = 3, n, Ii, J, Imax;
13   PetscMPIInt rank, size;
14   PetscScalar v, diag = -4.0;
15   IS          is;
16 
17   PetscFunctionBeginUser;
18   PetscCall(PetscInitialize(&argc, &args, (char *)0, help));
19   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
20   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
21   n = 2 * size;
22 
23   /* create A Square matrix for the five point stencil,YET AGAIN*/
24   PetscCall(MatCreate(PETSC_COMM_WORLD, &A));
25   PetscCall(MatSetSizes(A, PETSC_DECIDE, PETSC_DECIDE, m * n, m * n));
26   PetscCall(MatSetFromOptions(A));
27   PetscCall(MatSetUp(A));
28   for (i = 0; i < m; i++) {
29     for (j = 2 * rank; j < 2 * rank + 2; j++) {
30       v  = -1.0;
31       Ii = j + n * i;
32       if (i > 0) {
33         J = Ii - n;
34         PetscCall(MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES));
35       }
36       if (i < m - 1) {
37         J = Ii + n;
38         PetscCall(MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES));
39       }
40       if (j > 0) {
41         J = Ii - 1;
42         PetscCall(MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES));
43       }
44       if (j < n - 1) {
45         J = Ii + 1;
46         PetscCall(MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES));
47       }
48       v = 4.0;
49       PetscCall(MatSetValues(A, 1, &Ii, 1, &Ii, &v, INSERT_VALUES));
50     }
51   }
52   PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
53   PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
54 
55   /* Create AN IS required by MatZeroRows() */
56   Imax = n * rank;
57   if (Imax >= n * m - m - 1) Imax = m * n - m - 1;
58   PetscCall(ISCreateStride(PETSC_COMM_SELF, m, Imax, 1, &is));
59 
60   PetscCall(TestMatZeroRows_Basic(A, is, 0.0));
61   PetscCall(TestMatZeroRows_Basic(A, is, diag));
62 
63   PetscCall(TestMatZeroRows_with_no_allocation(A, is, 0.0));
64   PetscCall(TestMatZeroRows_with_no_allocation(A, is, diag));
65 
66   PetscCall(MatDestroy(&A));
67 
68   /* Now Create a rectangular matrix with five point stencil (app)
69    n+size is used so that this dimension is always divisible by size.
70    This way, we can always use bs = size for any number of procs */
71   PetscCall(MatCreate(PETSC_COMM_WORLD, &A));
72   PetscCall(MatSetSizes(A, PETSC_DECIDE, PETSC_DECIDE, m * n, m * (n + size)));
73   PetscCall(MatSetFromOptions(A));
74   PetscCall(MatSetUp(A));
75   for (i = 0; i < m; i++) {
76     for (j = 2 * rank; j < 2 * rank + 2; j++) {
77       v  = -1.0;
78       Ii = j + n * i;
79       if (i > 0) {
80         J = Ii - n;
81         PetscCall(MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES));
82       }
83       if (i < m - 1) {
84         J = Ii + n;
85         PetscCall(MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES));
86       }
87       if (j > 0) {
88         J = Ii - 1;
89         PetscCall(MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES));
90       }
91       if (j < n + size - 1) {
92         J = Ii + 1;
93         PetscCall(MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES));
94       }
95       v = 4.0;
96       PetscCall(MatSetValues(A, 1, &Ii, 1, &Ii, &v, INSERT_VALUES));
97     }
98   }
99   PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
100   PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
101 
102   PetscCall(TestMatZeroRows_Basic(A, is, 0.0));
103   PetscCall(TestMatZeroRows_Basic(A, is, diag));
104 
105   PetscCall(MatDestroy(&A));
106   PetscCall(ISDestroy(&is));
107   PetscCall(PetscFinalize());
108   return 0;
109 }
110 
111 PetscErrorCode TestMatZeroRows_Basic(Mat A, IS is, PetscScalar diag) {
112   Mat       B;
113   PetscBool keepnonzeropattern;
114 
115   /* Now copy A into B, and test it with MatZeroRows() */
116   PetscCall(MatDuplicate(A, MAT_COPY_VALUES, &B));
117 
118   PetscCall(PetscOptionsHasName(NULL, NULL, "-keep_nonzero_pattern", &keepnonzeropattern));
119   if (keepnonzeropattern) PetscCall(MatSetOption(B, MAT_KEEP_NONZERO_PATTERN, PETSC_TRUE));
120 
121   PetscCall(MatZeroRowsIS(B, is, diag, 0, 0));
122   PetscCall(MatView(B, PETSC_VIEWER_STDOUT_WORLD));
123   PetscCall(MatDestroy(&B));
124   return 0;
125 }
126 
127 PetscErrorCode TestMatZeroRows_with_no_allocation(Mat A, IS is, PetscScalar diag) {
128   Mat B;
129 
130   /* Now copy A into B, and test it with MatZeroRows() */
131   PetscCall(MatDuplicate(A, MAT_COPY_VALUES, &B));
132   /* Set this flag after assembly. This way, it affects only MatZeroRows() */
133   PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_TRUE));
134 
135   PetscCall(MatZeroRowsIS(B, is, diag, 0, 0));
136   PetscCall(MatView(B, PETSC_VIEWER_STDOUT_WORLD));
137   PetscCall(MatDestroy(&B));
138   return 0;
139 }
140 
141 /*TEST
142 
143    test:
144       nsize: 2
145       filter: grep -v " MPI process"
146 
147    test:
148       suffix: 2
149       nsize: 3
150       args: -mat_type mpibaij -mat_block_size 3
151       filter: grep -v " MPI process"
152 
153    test:
154       suffix: 3
155       nsize: 3
156       args: -mat_type mpiaij -keep_nonzero_pattern
157       filter: grep -v " MPI process"
158 
159    test:
160       suffix: 4
161       nsize: 3
162       args: -keep_nonzero_pattern -mat_type mpibaij -mat_block_size 3
163       filter: grep -v " MPI process"
164 
165 TEST*/
166