translate_gbvector_to_vec()

vec PolyRing::translate_gbvector_to_vec ( const FreeModule * F, const gbvector * v ) const

virtual

Implements PolynomialRing.

Definition at line 2639 of file poly.cpp.

{
  if (v == nullptr) return nullptr;
 
  if (getCoefficients() == globalQQ)
    return translate_gbvector_to_vec_QQ(F, v, globalZZ->one());
  GBRing *GR = get_gb_ring();
 
  int firstcomp = v->comp;
  int lastcomp = firstcomp;
  for (const gbvector *t = v->next; t != nullptr; t = t->next)
    {
      if (firstcomp > t->comp)
        firstcomp = t->comp;
      else if (lastcomp < t->comp)
        lastcomp = t->comp;
    }
 
  Nterm **vec_comps = newarray(Nterm *, lastcomp - firstcomp + 1);
  Nterm **vec_last = newarray(Nterm *, lastcomp - firstcomp + 1);
  for (int i = 0; i < lastcomp - firstcomp + 1; i++)
    {
      vec_comps[i] = nullptr;
      vec_last[i] = nullptr;
    }
 
  // Now make a list of Nterm's, copy gbvectors in (except comps)
  for (const gbvector *t = v; t != nullptr; t = t->next)
    {
      Nterm *s = new_term();
      GR->gbvector_get_lead_monomial(F, t, s->monom);
      s->coeff = t->coeff;
      s->next = nullptr;
      int x = t->comp - firstcomp;
      if (!vec_comps[x])
        {
          vec_comps[x] = s;
          vec_last[x] = s;
        }
      else
        {
          vec_last[x]->next = s;
          vec_last[x] = s;
        }
    }
 
  // Now create the vecs
  vec result = nullptr;
  for (int x = 0; x < lastcomp - firstcomp + 1; x++)
    if (vec_comps[x])
      {
        vec w = make_vec(x + firstcomp - 1, vec_comps[x]);
        w->next = result;
        result = w;
      }
 
  // Finally, free vec_last, vec_comps;
  freemem(vec_comps);
  freemem(vec_last);
 
  return result;
}

References gbvector::comp, freemem(), FreeModule, GBRing::gbvector_get_lead_monomial(), PolynomialRing::get_gb_ring(), PolynomialRing::getCoefficients(), globalQQ, globalZZ, Ring::make_vec(), new_term(), newarray, gbvector::next, Nterm::next, result(), s, translate_gbvector_to_vec_QQ(), and x.

Referenced by translate_gbvector_to_vec_denom().