create_quotient() [3/3]

PolynomialRing * PolynomialRing::create_quotient ( const PolynomialRing * R, VECTOR(Nterm *) & elems )

staticprotected

Definition at line 79 of file polyring.cpp.

{
  // Here are the cases:
  // (1) R is a polynomial ring over a basic field
  // (2) R is a polynomial ring over ZZ
  // (3) R is a polynomial ring over QQ
 
  // case (1), (2): PolyRingQuotient
  // case (3): PolyQQ
 
  PolynomialRing *result = nullptr;
  Ring::CoefficientType coeff_type = R->coefficient_type();
 
  QRingInfo *qrinfo = nullptr;
  switch (coeff_type)
    {
      case COEFF_BASIC:
        qrinfo = new QRingInfo_field_basic(R->getNumeratorRing(), elems);
        result = new PolyRingQuotient;
        break;
      case COEFF_QQ:
        qrinfo = new QRingInfo_field_QQ(R->getNumeratorRing(), elems);
        result = new PolyRingQuotient;
        break;
      case COEFF_ZZ:
        QRingInfo_ZZ *qrinfoZZ = new QRingInfo_ZZ(R->getNumeratorRing(), elems);
        qrinfo = qrinfoZZ;
        result = new PolyRingQuotient;
        result->is_ZZ_quotient_ = qrinfoZZ->is_ZZ_quotient();
        result->ZZ_quotient_value_ = qrinfoZZ->ZZ_quotient_value();
        break;
    }
 
  result->initialize_ring(
      R->characteristic(), R->get_degree_ring(), R->get_heft_vector());
 
  result->initialize_PolynomialRing(R->getCoefficients(),
                                    R->getMonoid(),
                                    R->getNumeratorRing(),
                                    R->getAmbientRing(),
                                    R->getDenominatorRing());
 
  result->gb_ring_ = R->get_gb_ring();
  result->setQuotientInfo(qrinfo);  // Also sets graded-ness
 
  result->zeroV = result->from_long(0);
  result->oneV = result->from_long(1);
  result->minus_oneV = result->from_long(-1);
 
  return result;
}

References Ring::characteristic(), Ring::COEFF_BASIC, Ring::COEFF_QQ, Ring::COEFF_ZZ, coefficient_type(), Ring::get_degree_ring(), get_gb_ring(), Ring::get_heft_vector(), getAmbientRing(), getCoefficients(), getDenominatorRing(), getMonoid(), getNumeratorRing(), QRingInfo_ZZ::is_ZZ_quotient(), PolynomialRing(), result(), and QRingInfo_ZZ::ZZ_quotient_value().

Referenced by create_quotient(), create_quotient(), IM2_Ring_quotient(), and IM2_Ring_quotient1().