xref: /petsc/src/mat/tests/ex209.c (revision a69119a591a03a9d906b29c0a4e9802e4d7c9795)
1 static char help[] = "Test MatTransposeMatMult() \n\n";
2 
3 /* Example:
4   mpiexec -n 8 ./ex209 -f <inputfile> (e.g., inputfile=ceres_solver_iteration_001_A.petsc)
5 */
6 
7 #include <petscmat.h>
8 
9 int main(int argc, char **args) {
10   Mat         A, C, AtA, B;
11   PetscViewer fd;
12   char        file[PETSC_MAX_PATH_LEN];
13   PetscReal   fill = 4.0;
14   PetscMPIInt rank, size;
15   PetscBool   equal;
16   PetscInt    i, m, n, rstart, rend;
17   PetscScalar one = 1.0;
18 
19   PetscFunctionBeginUser;
20   PetscCall(PetscInitialize(&argc, &args, (char *)0, help));
21   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
22   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
23   PetscCall(PetscOptionsGetString(NULL, NULL, "-f", file, sizeof(file), NULL));
24 
25   /* Load matrix A */
26   PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, file, FILE_MODE_READ, &fd));
27   PetscCall(MatCreate(PETSC_COMM_WORLD, &A));
28   PetscCall(MatSetType(A, MATAIJ));
29   PetscCall(MatLoad(A, fd));
30   PetscCall(PetscViewerDestroy(&fd));
31 
32   /* Create identity matrix B */
33   PetscCall(MatGetLocalSize(A, &m, &n));
34   PetscCall(MatCreate(PETSC_COMM_WORLD, &B));
35   PetscCall(MatSetSizes(B, m, m, PETSC_DECIDE, PETSC_DECIDE));
36   PetscCall(MatSetType(B, MATAIJ));
37   PetscCall(MatSetFromOptions(B));
38   PetscCall(MatSetUp(B));
39 
40   PetscCall(MatGetOwnershipRange(B, &rstart, &rend));
41   for (i = rstart; i < rend; i++) PetscCall(MatSetValues(B, 1, &i, 1, &i, &one, INSERT_VALUES));
42   PetscCall(MatAssemblyBegin(B, MAT_FINAL_ASSEMBLY));
43   PetscCall(MatAssemblyEnd(B, MAT_FINAL_ASSEMBLY));
44 
45   /* Compute AtA = A^T*B*A, B = identity matrix */
46   PetscCall(MatPtAP(B, A, MAT_INITIAL_MATRIX, fill, &AtA));
47   PetscCall(MatPtAP(B, A, MAT_REUSE_MATRIX, fill, &AtA));
48   if (rank == 0) printf("C = A^T*B*A is done...\n");
49   PetscCall(MatDestroy(&B));
50 
51   /* Compute C = A^T*A */
52   PetscCall(MatTransposeMatMult(A, A, MAT_INITIAL_MATRIX, fill, &C));
53   if (rank == 0) printf("C = A^T*A is done...\n");
54   PetscCall(MatTransposeMatMult(A, A, MAT_REUSE_MATRIX, fill, &C));
55   if (rank == 0) printf("REUSE C = A^T*A is done...\n");
56 
57   /* Compare C and AtA */
58   PetscCall(MatMultEqual(C, AtA, 20, &equal));
59   PetscCheck(equal, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "A^T*A != At*A");
60   PetscCall(MatDestroy(&AtA));
61 
62   PetscCall(MatDestroy(&C));
63   PetscCall(MatDestroy(&A));
64   PetscCall(PetscFinalize());
65   return 0;
66 }
67 
68 /*TEST
69 
70    test:
71       requires: datafilespath !complex double !defined(PETSC_USE_64BIT_INDICES)
72       args: -f ${DATAFILESPATH}/matrices/arco1
73 
74    test:
75       suffix: 2
76       nsize: 4
77       requires: datafilespath !complex double !defined(PETSC_USE_64BIT_INDICES)
78       args: -f ${DATAFILESPATH}/matrices/arco1 -matptap_via nonscalable
79 
80 TEST*/
81