tensor()

Matrix * Matrix::tensor

(

const Matrix *

m

)

const

Definition at line 780 of file matrix.cpp.

{
  auto R = get_ring();
  if (R != m->get_ring())
    {
      ERROR("matrix tensor: different base rings");
      return nullptr;
    }
 
  const FreeModule *F = rows()->tensor(m->rows());
  const FreeModule *G = cols()->tensor(m->cols());
 
  auto D = R->degree_monoid();
  monomial deg = D->make_new(degree_shift());
  D->mult(deg, m->degree_shift(), deg);
 
  MatrixConstructor mat(F, G, deg);
  D->remove(deg);
  int i, j, next = 0;
  for (i = 0; i < n_cols(); i++)
    for (j = 0; j < m->n_cols(); j++)
      mat.set_column(next++, R->tensor(rows(), elem(i), m->rows(), (*m)[j]));
  return mat.to_matrix();
}

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

Referenced by IM2_Matrix_tensor(), and tensor().