get_logical_coeff()

ring_elem PolyRing::get_logical_coeff ( const Ring * coeffR, const Nterm *& f ) const

protected

Definition at line 1701 of file poly.cpp.

{
  if (f == nullptr) return coeffR->zero();
  if (coeffR == K_)
    {
      ring_elem result = f->coeff;
      f = f->next;
      return result;
    }
  const PolynomialRing *KR = coeffR->cast_to_PolynomialRing();
  assert(KR);
  const PolyRing *K = KR->getNumeratorRing();
  Nterm head;
  Nterm *inresult = &head;
  inresult->next = nullptr;
  exponents_t exp = newarray_atomic(int, n_vars());
  exponents_t exp2 = newarray_atomic(int, n_vars());
  int nvars = n_vars() - K->n_vars();
  M_->to_expvector(f->monom, exp);
  exponents::copy(n_vars(), exp, exp2);
  do
    {
      Nterm *t = K->new_term();
      inresult->next = t;
      inresult = t;
      t->coeff = f->coeff;
      K->getMonoid()->from_expvector(exp2 + nvars, t->monom);
 
      f = f->next;
      if (f == nullptr) break;
      M_->to_expvector(f->monom, exp2);
    }
  while (EQ == exponents::lex_compare(nvars, exp, exp2));
  inresult->next = nullptr;
  return head.next;
}

References Nterm::coeff, ExponentVector< int, true >::copy(), EQ, Monoid::from_expvector(), PolynomialRing::getMonoid(), PolynomialRing::getNumeratorRing(), PolynomialRing::K_, ExponentVector< int, true >::lex_compare(), PolynomialRing::M_, Nterm::monom, PolynomialRing::n_vars(), new_term(), newarray_atomic, Nterm::next, PolynomialRing::PolynomialRing(), PolyRing(), result(), and Ring::Ring().

Referenced by get_coeff(), lead_logical_coeff(), and list_form().