xref: /petsc/src/mat/tests/ex81.c (revision e91c04dfc8a52dee1965211bb1cc8e5bf775178f)
1 static char help[] = "Tests MatOption MAT_FORCE_DIAGONAL_ENTRIES.\n\n";
2 
3 #include <petscmat.h>
4 
5 int main(int argc, char **args)
6 {
7   Mat         A, B;
8   Vec         diag;
9   PetscInt    i, n = 10, col[3], test;
10   PetscScalar v[3];
11 
12   PetscFunctionBeginUser;
13   PetscCall(PetscInitialize(&argc, &args, NULL, help));
14   PetscCall(PetscOptionsGetInt(NULL, NULL, "-n", &n, NULL));
15 
16   /* Create A which has empty 0-th row and column */
17   PetscCall(MatCreate(PETSC_COMM_WORLD, &A));
18   PetscCall(MatSetSizes(A, PETSC_DECIDE, PETSC_DECIDE, n, n));
19   PetscCall(MatSetType(A, MATAIJ));
20   PetscCall(MatSetFromOptions(A));
21   PetscCall(MatSetUp(A));
22 
23   v[0] = -1.;
24   v[1] = 2.;
25   v[2] = -1.;
26   for (i = 2; i < n - 1; i++) {
27     col[0] = i - 1;
28     col[1] = i;
29     col[2] = i + 1;
30     PetscCall(MatSetValues(A, 1, &i, 3, col, v, INSERT_VALUES));
31   }
32   i      = 1;
33   col[0] = 1;
34   col[1] = 2;
35   PetscCall(MatSetValues(A, 1, &i, 2, col, v + 1, INSERT_VALUES));
36   i      = n - 1;
37   col[0] = n - 2;
38   col[1] = n - 1;
39   PetscCall(MatSetValues(A, 1, &i, 2, col, v, INSERT_VALUES));
40   PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
41   PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
42 
43   for (test = 0; test < 2; test++) {
44     PetscCall(MatProductCreate(A, A, NULL, &B));
45 
46     if (test == 0) {
47       /* Compute B = A*A; B misses 0-th diagonal */
48       PetscCall(MatProductSetType(B, MATPRODUCT_AB));
49       PetscCall(MatSetOptionsPrefix(B, "AB_"));
50     } else {
51       /* Compute B = A^t*A; B misses 0-th diagonal */
52       PetscCall(MatProductSetType(B, MATPRODUCT_AtB));
53       PetscCall(MatSetOptionsPrefix(B, "AtB_"));
54     }
55 
56     /* Force allocate missing diagonal entries of B */
57     PetscCall(MatSetOption(B, MAT_FORCE_DIAGONAL_ENTRIES, PETSC_TRUE));
58     PetscCall(MatProductSetFromOptions(B));
59 
60     PetscCall(MatProductSymbolic(B));
61     PetscCall(MatProductNumeric(B));
62 
63     PetscCall(MatSetOption(B, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));
64 
65     /* Insert entries to diagonal of B */
66     PetscCall(MatCreateVecs(B, NULL, &diag));
67     PetscCall(MatGetDiagonal(B, diag));
68     PetscCall(VecSetValue(diag, 0, 100.0, INSERT_VALUES));
69     PetscCall(VecAssemblyBegin(diag));
70     PetscCall(VecAssemblyEnd(diag));
71 
72     PetscCall(MatDiagonalSet(B, diag, INSERT_VALUES));
73     if (test == 1) PetscCall(MatView(B, PETSC_VIEWER_STDOUT_WORLD));
74     PetscCall(MatDestroy(&B));
75     PetscCall(VecDestroy(&diag));
76   }
77 
78   PetscCall(MatDestroy(&A));
79   PetscCall(PetscFinalize());
80   return 0;
81 }
82 
83 /*TEST
84 
85    test:
86      output_file: output/ex81_1.out
87 
88    test:
89      suffix: 2
90      args: -AtB_mat_product_algorithm at*b
91      output_file: output/ex81_1.out
92 
93    test:
94      suffix: 3
95      args: -AtB_mat_product_algorithm outerproduct
96      output_file: output/ex81_1.out
97 
98    test:
99      suffix: 4
100      nsize: 3
101      args: -AtB_mat_product_algorithm nonscalable
102      output_file: output/ex81_3.out
103 
104    test:
105      suffix: 5
106      nsize: 3
107      args: -AtB_mat_product_algorithm scalable
108      output_file: output/ex81_3.out
109 
110    test:
111      suffix: 6
112      nsize: 3
113      args: -AtB_mat_product_algorithm at*b
114      output_file: output/ex81_3.out
115 
116 TEST*/
117