QRingInfo_field()

QRingInfo_field::QRingInfo_field	(	const PolyRing *	ambientR,
		const VECTOR(Nterm *) &	quotients )

Definition at line 43 of file qring.cpp.

    : QRingInfo(ambientR)
// This constructs the quotient ideal, and sets the MonomialIdeal.
// A subset of 'quotients' must be a minimal GB, and any non-minimal elements
// should be writable in terms of previous ones.
// IE, in constructing (R/I)/J, the GB elements of J (mod I), together with the
// GB elements of I, form a GB, but the GB elements of I might not be minimal.
// In this case, 'quotients' should be the list of GB elements of J followed by
// those
// of I.
//
// The ideal may be in a tower of polynomial rings, in which case it needs to be
// a GB over the flattened ring.
{
  Rideal = new MonomialIdeal(R);
  ringtable = MonomialTable::make(R->n_vars());
  gc_vector<int> vp;
  exponents_t exp = newarray_atomic(int, R->n_vars());
  for (int i = 0; i < quotients.size(); i++)
    {
      // Make a varpower element.  See if it is in Rideal.
      // If not, place it into quotient_elements_.
 
      Nterm *f = quotients[i];
      R->getMonoid()->to_expvector(f->monom, exp);
 
      Bag *not_used;
 
      if (!Rideal->search_expvector(exp, not_used))
        {
          // The element is part of a minimal GB
          int index = n_quotients();
          gbvector *g = R->translate_gbvector_from_ringelem(f);
          appendQuotientElement(f, g);
          R->getMonoid()->to_varpower(f->monom, vp);
          Bag *b = new Bag(index, vp);
          Rideal->insert(b);
          ringtable->insert(exp, 1, index);  // consumes exp
          exp = newarray_atomic(int, R->n_vars());
        }
    }
  freemem(exp);
}

References QRingInfo::appendQuotientElement(), freemem(), MonomialTable::make(), Nterm::monom, QRingInfo::n_quotients(), newarray_atomic, QRingInfo::QRingInfo(), QRingInfo::R, Rideal, and ringtable.

Referenced by QRingInfo_field_basic::QRingInfo_field_basic(), and QRingInfo_field_QQ::QRingInfo_field_QQ().