rawNCBasis()

const Matrix * rawNCBasis	(	const Matrix *	gb2SidedIdeal,
		M2_arrayint	lo_degree,
		M2_arrayint	hi_degree,
		int	limit )

Definition at line 1001 of file groebner.cpp.

{
  const Ring* R = gb2SidedIdeal->get_ring();
  if (R == nullptr)
    {
      ERROR("internal error: expected non-null Ring!");
      return nullptr;
    }
  try {
    const M2FreeAlgebra* A = R->cast_to_M2FreeAlgebra();
    if (A != nullptr)
      {
        ConstPolyList G = matrixToPolyList(A, gb2SidedIdeal);
 
        // WARNING: The following line creates new polynomials
        // which are used directly in vectorToMatrix (without copying)
        // but when result goes out of scope, the list is deleted,
        // but not the polynomials themselves, as they are pointers.
        PolyList result;
        bool worked = ncBasis(A->freeAlgebra(),
                              G,
                              M2_arrayint_to_stdvector<int>(lo_degree),
                              M2_arrayint_to_stdvector<int>(hi_degree),
                              limit,
                              result);
        if (not worked) return nullptr;
        return polyListToMatrix(A, result, 1, result.size()); // consumes entries of result
      }
    ERROR("expected a free algebra");
    return nullptr;
  }
  catch (exc::engine_error& e) {
    ERROR(e.what());
    return nullptr;
  }
}

References Ring::cast_to_M2FreeAlgebra(), ERROR, M2FreeAlgebra::freeAlgebra(), G, Matrix::get_ring(), M2_arrayint_to_stdvector(), Matrix, matrixToPolyList(), ncBasis(), polyListToMatrix(), and result().