Actual source code: ex209.c

  1: static char help[] = "Test MatTransposeMatMult() \n\n";

  3: /* Example:
  4:   mpiexec -n 8 ./ex209 -f <inputfile> (e.g., inputfile=ceres_solver_iteration_001_A.petsc)
  5: */

  7: #include <petscmat.h>

  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;

 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));

 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));

 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));

 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));

 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));

 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");

 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));

 63:   PetscCall(MatDestroy(&C));
 64:   PetscCall(MatDestroy(&A));
 65:   PetscCall(PetscFinalize());
 66:   return 0;
 67: }

 69: /*TEST

 71:    test:
 72:       requires: datafilespath !complex double !defined(PETSC_USE_64BIT_INDICES)
 73:       args: -f ${DATAFILESPATH}/matrices/arco1

 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

 81: TEST*/