module_tensor()

Matrix * Matrix::module_tensor

(

const Matrix *

m

)

const

Definition at line 686 of file matrix.cpp.

{
  auto R = get_ring();
  if (R != m->get_ring())
    {
      ERROR("module tensor: different base rings");
      return nullptr;
    }
  FreeModule *F = rows()->tensor(m->rows());
  FreeModule *G = rows()->tensor(m->cols());
  FreeModule *G1 = m->rows()->tensor(cols());
  G->direct_sum_to(G1);
  freemem(G1);
 
  MatrixConstructor mat(F, G, nullptr);
 
  int i, j, next = 0;
 
  for (i = 0; i < n_rows(); i++)
    for (j = 0; j < m->n_cols(); j++)
      mat.set_column(next++, R->component_shift(i * m->n_rows(), m->elem(j)));
 
  for (i = 0; i < m->n_rows(); i++)
    for (j = 0; j < n_cols(); j++)
      mat.set_column(next++, R->tensor_shift(m->n_rows(), i, elem(j)));
  return mat.to_matrix();
}

References cols(), elem(), ERROR, freemem(), FreeModule, G, get_ring(), Matrix(), MatrixConstructor, module_tensor(), n_cols(), n_rows(), rows(), MatrixConstructor::set_column(), FreeModule::tensor(), and MatrixConstructor::to_matrix().

Referenced by module_tensor(), and rawModuleTensor().