Method copyVecToArray

src/IB/CIBMethod.cpp:1253–1324

} // computeNetRigidGeneralizedForce

void
CIBMethod::copyVecToArray(Vec b,
                          double* array,
                          const std::vector<unsigned int>& struct_ids,
                          const int data_depth,
                          const int array_rank)
{
    if (struct_ids.empty()) return;
    const auto num_structs = static_cast<unsigned>(struct_ids.size());

    // Get the Lagrangian indices of the structures.
    std::vector<int> map;
    PetscInt total_nodes = 0;
    for (unsigned k = 0; k < num_structs; ++k)
    {
        total_nodes += getNumberOfNodes(struct_ids[k]);
    }
    map.reserve(total_nodes);
    for (unsigned k = 0; k < num_structs; ++k)
    {
        const std::pair<int, int>& lag_idx_range = d_struct_lag_idx_range[struct_ids[k]];
        const unsigned struct_nodes = getNumberOfNodes(struct_ids[k]);
        for (unsigned j = 0; j < struct_nodes; ++j)
        {
            map.push_back(lag_idx_range.first + j);
        }
    }

    // Map the Lagrangian indices into PETSc indices
    const int struct_ln = getStructuresLevelNumber();
    d_l_data_manager->mapLagrangianToPETSc(map, struct_ln);

    // Wrap the raw data in a PETSc Vec
    PetscInt size = total_nodes * data_depth;
    int rank = IBTK_MPI::getRank();
    PetscInt array_local_size = 0;
    if (rank == array_rank) array_local_size = size;
    Vec array_vec;
    VecCreateMPIWithArray(PETSC_COMM_WORLD, /*blocksize*/ 1, array_local_size, PETSC_DECIDE, array, &array_vec);

    // Create index sets to define global index mapping.
    std::vector<PetscInt> vec_indices, array_indices;
    vec_indices.reserve(size);
    array_indices.reserve(size);
    for (PetscInt j = 0; j < total_nodes; ++j)
    {
        PetscInt petsc_idx = map[j];
        for (int d = 0; d < data_depth; ++d)
        {
            array_indices.push_back(j * data_depth + d);
            vec_indices.push_back(petsc_idx * data_depth + d);
        }
    }
    IS is_vec;
    IS is_array;
    ISCreateGeneral(PETSC_COMM_SELF, size, &vec_indices[0], PETSC_COPY_VALUES, &is_vec);
    ISCreateGeneral(PETSC_COMM_SELF, size, &array_indices[0], PETSC_COPY_VALUES, &is_array);