xref: /petsc/src/mat/tests/ex90.c (revision df4cd43f92eaa320656440c40edb1046daee8f75)
1 
2 static char help[] = "Tests MatPtAP() \n";
3 
4 #include <petscmat.h>
5 
6 /*
7  * This is an extremely simple example to test MatPtAP. It is very useful when developing and debugging the code.
8  *
9  * A =
10 
11    1   2   0   4
12    0   1   2   0
13    2   0   4   0
14    0   1   2   1
15  *
16  *
17  *
18  * P =
19 
20    1.00000   0.00000
21    0.30000   0.50000
22    0.00000   0.80000
23    0.90000   0.00000
24  *
25  *
26  *AP =
27  *
28  * 5.20000   1.00000
29    0.30000   2.10000
30    2.00000   3.20000
31    1.20000   2.10000
32  *
33  * PT =
34 
35    1.00000   0.30000   0.00000   0.90000
36    0.00000   0.50000   0.80000   0.00000
37 
38  *
39  * C =
40 
41    6.3700   3.5200
42    1.7500   3.6100
43  *
44  * */
45 
46 int main(int argc, char **argv)
47 {
48   Mat         A, P, PtAP;
49   PetscInt    i1[] = {0, 3, 5}, i2[] = {0, 2, 5};
50   PetscInt    j1[] = {0, 1, 3, 1, 2}, j2[] = {0, 2, 1, 2, 3};
51   PetscScalar a1[] = {1, 2, 4, 1, 2}, a2[] = {2, 4, 1, 2, 1};
52   PetscInt    pi1[] = {0, 1, 3}, pi2[] = {0, 1, 2};
53   PetscInt    pj1[] = {0, 0, 1}, pj2[] = {1, 0};
54   PetscScalar pa1[] = {1, 0.3, 0.5}, pa2[] = {0.8, 0.9};
55   MPI_Comm    comm;
56   PetscMPIInt rank, size;
57 
58   PetscFunctionBeginUser;
59   PetscCall(PetscInitialize(&argc, &argv, NULL, help));
60   comm = PETSC_COMM_WORLD;
61   PetscCallMPI(MPI_Comm_rank(comm, &rank));
62   PetscCallMPI(MPI_Comm_size(comm, &size));
63   PetscCheck(size == 2, comm, PETSC_ERR_WRONG_MPI_SIZE, "You have to use two processor cores to run this example ");
64   PetscCall(MatCreateMPIAIJWithArrays(comm, 2, 2, PETSC_DETERMINE, PETSC_DETERMINE, rank ? i2 : i1, rank ? j2 : j1, rank ? a2 : a1, &A));
65   PetscCall(MatCreateMPIAIJWithArrays(comm, 2, 1, PETSC_DETERMINE, PETSC_DETERMINE, rank ? pi2 : pi1, rank ? pj2 : pj1, rank ? pa2 : pa1, &P));
66   PetscCall(MatPtAP(A, P, MAT_INITIAL_MATRIX, 1.1, &PtAP));
67   PetscCall(MatView(A, NULL));
68   PetscCall(MatView(P, NULL));
69   PetscCall(MatView(PtAP, NULL));
70   PetscCall(MatPtAP(A, P, MAT_REUSE_MATRIX, 1.1, &PtAP));
71   PetscCall(MatView(A, NULL));
72   PetscCall(MatView(P, NULL));
73   PetscCall(MatView(PtAP, NULL));
74   PetscCall(MatDestroy(&A));
75   PetscCall(MatDestroy(&P));
76   PetscCall(MatDestroy(&PtAP));
77   PetscCall(PetscFinalize());
78   return 0;
79 }
80 
81 /*TEST
82    test:
83      nsize: 2
84      args:   -matptap_via allatonce
85      output_file: output/ex90_1.out
86 
87    test:
88      nsize: 2
89      suffix: merged
90      args:   -matptap_via allatonce_merged
91      output_file: output/ex90_1.out
92 
93 TEST*/
94