simplify()

void LocalRing::simplify ( local_elem * f ) const

private

Definition at line 73 of file localring.cpp.

{
  ring_elem x, y;
  if (use_gcd_simplify)
    {
      y = f->denom;
      if (mRing->is_equal(y, mRing->one())) return;
      x = f->numer;
      const RingElement *a = RingElement::make_raw(mRing, x);
      const RingElement *b = RingElement::make_raw(mRing, y);
      const RingElement *c = rawGCDRingElement(a, b, nullptr, false);
 
#if 0
      // Debugging code
            buffer o;
            o << newline;
            o << "a = ";
            a->text_out(o);
            o << "  b = ";
            b->text_out(o);
            o << " gcd = ";
            c->text_out(o);
            o << newline;
            emit(o.str());
#endif
      if (!mRing->is_equal(c->get_value(), mRing->one()))
        {
          f->numer = mRing->divide(f->numer, c->get_value());
          f->denom = mRing->divide(f->denom, c->get_value());
        }
      // Now, let's take the content of the denominator, and divide the
      // numerator
      // and denominator by this value.
      ring_elem ct = mRing->content(
          f->denom, f->numer);  // result is in mRing->getCoefficients()
 
#if 0
            o.reset();
            o << "f->numer = ";
            mRing->elem_text_out(o,f->numer);
            o << "  f->denom = ";
            mRing->elem_text_out(o,f->denom);
            o << " ass= ";
            mRing->getCoefficients()->elem_text_out(o,ct);
            o << newline;
            emit(o.str());
#endif
 
      if (!mRing->getCoefficients()->is_equal(ct,
                                              mRing->getCoefficients()->one()))
        {
          f->numer = mRing->divide_by_given_content(f->numer, ct);
          f->denom = mRing->divide_by_given_content(f->denom, ct);
        }
    }
  else
    {
      mRing->syzygy(f->numer, f->denom, x, y);
      if (mRing->is_zero(x))
        {
          mRing->remove(x);
          set_non_unit_frac(f->denom);
          f->numer = mRing->zero();
          f->denom = mRing->one();
          return;
        }
      mRing->negate_to(y);
      mRing->remove(f->numer);
      mRing->remove(f->denom);
      f->numer = y;
      f->denom = x;
    }
}

References local_elem::denom, emit(), RingElement::get_value(), RingElement::make_raw(), mRing, newline, local_elem::numer, rawGCDRingElement(), buffer::reset(), set_non_unit_frac(), buffer::str(), RingElement::text_out(), use_gcd_simplify, and x.

Referenced by make_elem().