matrix_remainder()

const Matrix * GB_comp::matrix_remainder ( const Matrix * m )

virtual

Implements GBComputation.

Definition at line 1070 of file gb-homog2.cpp.

{
  if (m->get_ring() != originalR)
    {
      ERROR("expected matrix over the same ring");
      return nullptr;
    }
 
  if (m->n_rows() != _F->rank())
    {
      ERROR("expected matrices to have same number of rows");
      return nullptr;
    }
  start_computation();
  MatrixConstructor red(m->rows(), m->cols(), m->degree_shift());
  for (int i = 0; i < m->n_cols(); i++)
    {
      ring_elem denom;
      gbvector *f = originalR->translate_gbvector_from_vec(_F, (*m)[i], denom);
      gbvector *fsyz = _GR->gbvector_zero();
 
      gb_reduce(f, fsyz);
 
      vec fv = originalR->translate_gbvector_to_vec_denom(_F, f, denom);
      red.set_column(i, fv);
    }
  return red.to_matrix();
}

References _F, _GR, Matrix::cols(), Matrix::degree_shift(), ERROR, gb_reduce(), Matrix::get_ring(), Matrix, Matrix::n_cols(), Matrix::n_rows(), originalR, Matrix::rows(), MatrixConstructor::set_column(), start_computation(), and MatrixConstructor::to_matrix().