Beispiel #1
0
void add_matrix_to_matrix(double scalar,
                          const fei::Matrix& src_matrix,
                          fei::Matrix& dest_matrix)
{
  fei::SharedPtr<fei::VectorSpace> vspace = src_matrix.getMatrixGraph()->getRowSpace();

  int numRows = vspace->getNumIndices_Owned();
  std::vector<int> rows(numRows);
  vspace->getIndices_Owned(numRows, &rows[0], numRows);

  std::vector<int> indices;
  std::vector<double> coefs;

  for(size_t i=0; i<rows.size(); ++i) {
    int rowlen = 0;
    src_matrix.getRowLength(rows[i], rowlen);

    if ((int)indices.size() < rowlen) {
      indices.resize(rowlen);
      coefs.resize(rowlen);
    }

    src_matrix.copyOutRow(rows[i], rowlen, &coefs[0], &indices[0]);

    for(int j=0; j<rowlen; ++j) {
      coefs[j] *= scalar;
    }

    double* coefPtr = &coefs[0];
    dest_matrix.sumIn(1, &rows[i], rowlen, &indices[0], &coefPtr);
  }
}
void assemble_elem_matrices_and_vectors(stk::mesh::BulkData& mesh,
                                        stk::mesh::FieldBase& field,
                                        stk::linsys::DofMapper& dof_mapper,
                                        fei::Matrix& matrix,
                                        fei::Vector& rhs)
{
  stk::mesh::fem::FEMMetaData &fem = stk::mesh::fem::FEMMetaData::get(mesh);
  const stk::mesh::EntityRank element_rank = fem.element_rank();

  const std::vector<stk::mesh::Bucket*>& mesh_buckets = mesh.buckets(element_rank);

  std::vector<stk::mesh::Bucket*> part_buckets;
  stk::mesh::Selector select_owned(stk::mesh::MetaData::get(mesh).locally_owned_part());
  stk::mesh::get_buckets(select_owned, mesh_buckets, part_buckets);

  int field_id = dof_mapper.get_field_id(field);

  stk::mesh::Entity& first_entity = *(part_buckets[0]->begin());
  stk::mesh::PairIterRelation rel = first_entity.relations(stk::mesh::fem::FEMMetaData::NODE_RANK);
  int num_nodes_per_elem = rel.second - rel.first;

  fei::SharedPtr<fei::MatrixGraph> matgraph = matrix.getMatrixGraph();
  int pattern_id = matgraph->definePattern(num_nodes_per_elem, stk::mesh::fem::FEMMetaData::NODE_RANK, field_id);

  std::vector<int> node_ids(num_nodes_per_elem);

  const int field_size = dof_mapper.get_fei_VectorSpace()->getFieldSize(field_id);
  const int matsize = num_nodes_per_elem*field_size*num_nodes_per_elem*field_size;
  const int vecsize = num_nodes_per_elem*field_size;

  std::vector<double> elem_matrix_1d(matsize, 0);
  std::vector<double*> elem_matrix_2d(vecsize);

  std::vector<double> elem_vector(vecsize, 0);

  for(size_t i=0; i<elem_matrix_2d.size(); ++i) {
    elem_matrix_2d[i] = &elem_matrix_1d[i*vecsize];
  }

  //fill our dummy elem-matrix:
  //This dummy matrix will be the same for every element. A real application
  //would form a different elem-matrix for each element.
  for(size_t i=0; i<elem_matrix_2d.size(); ++i) {
    double* row = elem_matrix_2d[i];
    if (i>=1) row[i-1] = -1;
    row[i] = 2;
    if (i<elem_matrix_2d.size()-1) row[i+1] = -1;

    elem_vector[i] = 1;
  }

  std::vector<int> eqn_indices(vecsize);

  for(size_t i=0; i<part_buckets.size(); ++i) {
    stk::mesh::Bucket::iterator
      b_iter = part_buckets[i]->begin(),
             b_end  = part_buckets[i]->end();
    for(; b_iter != b_end; ++b_iter) {
      stk::mesh::Entity& elem = *b_iter;
      rel = elem.relations(stk::mesh::fem::FEMMetaData::NODE_RANK);
      for(int j=0; rel.first != rel.second; ++rel.first, ++j) {
        node_ids[j] = rel.first->entity()->identifier();
      }

      matgraph->getPatternIndices(pattern_id, &node_ids[0], eqn_indices);

      matrix.sumIn(vecsize, &eqn_indices[0], vecsize, &eqn_indices[0],
                    &elem_matrix_2d[0]);
      rhs.sumIn(vecsize, &eqn_indices[0], &elem_vector[0]);
    }
  }
}