get_coeff()

ring_elem PolyRing::get_coeff ( const Ring * coeffR, const ring_elem f, const_varpower vp ) const

virtual

Definition at line 1989 of file poly.cpp.

{
  int nvars0 = check_coeff_ring(coeffR, this);
  if (nvars0 < 0) return from_long(0);
 
  exponents_t exp = newarray_atomic(int, nvars0);
  exponents_t exp2 = newarray_atomic(int, n_vars());  // FLAT number of variables
  varpower::to_expvector(nvars0, vp, exp);
 
  // Now loop thru f until exponents match up.
  const Nterm *t = f;
  for (; t != nullptr; t = t->next)
    {
      M_->to_expvector(t->monom, exp2);
      if (EQ == exponents::lex_compare(nvars0, exp, exp2)) break;
    }
 
  ring_elem result = get_logical_coeff(coeffR, t);
  freemem(exp2);
  freemem(exp);
  return result;
}

References check_coeff_ring(), EQ, freemem(), from_long(), get_logical_coeff(), ExponentVector< int, true >::lex_compare(), PolynomialRing::M_, Nterm::monom, PolynomialRing::n_vars(), newarray_atomic, Nterm::next, result(), Ring::Ring(), and ExponentList< int, true >::to_expvector().