xref: /petsc/src/mat/tests/ex209.c (revision d5b43468fb8780a8feea140ccd6fa3e6a50411cc)
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 {
11   Mat         A, C, AtA, B;
12   PetscViewer fd;
13   char        file[PETSC_MAX_PATH_LEN];
14   PetscReal   fill = 4.0;
15   PetscMPIInt rank, size;
16   PetscBool   equal;
17   PetscInt    i, m, n, rstart, rend;
18   PetscScalar one = 1.0;
19 
20   PetscFunctionBeginUser;
21   PetscCall(PetscInitialize(&argc, &args, (char *)0, help));
22   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
23   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
24   PetscCall(PetscOptionsGetString(NULL, NULL, "-f", file, sizeof(file), NULL));
25 
26   /* Load matrix A */
27   PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, file, FILE_MODE_READ, &fd));
28   PetscCall(MatCreate(PETSC_COMM_WORLD, &A));
29   PetscCall(MatSetType(A, MATAIJ));
30   PetscCall(MatLoad(A, fd));
31   PetscCall(PetscViewerDestroy(&fd));
32 
33   /* Create identity matrix B */
34   PetscCall(MatGetLocalSize(A, &m, &n));
35   PetscCall(MatCreate(PETSC_COMM_WORLD, &B));
36   PetscCall(MatSetSizes(B, m, m, PETSC_DECIDE, PETSC_DECIDE));
37   PetscCall(MatSetType(B, MATAIJ));
38   PetscCall(MatSetFromOptions(B));
39   PetscCall(MatSetUp(B));
40 
41   PetscCall(MatGetOwnershipRange(B, &rstart, &rend));
42   for (i = rstart; i < rend; i++) PetscCall(MatSetValues(B, 1, &i, 1, &i, &one, INSERT_VALUES));
43   PetscCall(MatAssemblyBegin(B, MAT_FINAL_ASSEMBLY));
44   PetscCall(MatAssemblyEnd(B, MAT_FINAL_ASSEMBLY));
45 
46   /* Compute AtA = A^T*B*A, B = identity matrix */
47   PetscCall(MatPtAP(B, A, MAT_INITIAL_MATRIX, fill, &AtA));
48   PetscCall(MatPtAP(B, A, MAT_REUSE_MATRIX, fill, &AtA));
49   if (rank == 0) printf("C = A^T*B*A is done...\n");
50   PetscCall(MatDestroy(&B));
51 
52   /* Compute C = A^T*A */
53   PetscCall(MatTransposeMatMult(A, A, MAT_INITIAL_MATRIX, fill, &C));
54   if (rank == 0) printf("C = A^T*A is done...\n");
55   PetscCall(MatTransposeMatMult(A, A, MAT_REUSE_MATRIX, fill, &C));
56   if (rank == 0) printf("REUSE C = A^T*A is done...\n");
57 
58   /* Compare C and AtA */
59   PetscCall(MatMultEqual(C, AtA, 20, &equal));
60   PetscCheck(equal, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "A^T*A != At*A");
61   PetscCall(MatDestroy(&AtA));
62 
63   PetscCall(MatDestroy(&C));
64   PetscCall(MatDestroy(&A));
65   PetscCall(PetscFinalize());
66   return 0;
67 }
68 
69 /*TEST
70 
71    test:
72       requires: datafilespath !complex double !defined(PETSC_USE_64BIT_INDICES)
73       args: -f ${DATAFILESPATH}/matrices/arco1
74 
75    test:
76       suffix: 2
77       nsize: 4
78       requires: datafilespath !complex double !defined(PETSC_USE_64BIT_INDICES)
79       args: -f ${DATAFILESPATH}/matrices/arco1 -matptap_via nonscalable
80 
81 TEST*/
82