gbvector_remove_content_ZZ()

void GBRing::gbvector_remove_content_ZZ ( gbvector * f, gbvector * fsyz, bool use_denom, ring_elem & denom ) const

protected

Definition at line 1315 of file gbring.cpp.

{
  // This routine assumes that the coeff ring is ZZ (originally QQ).
  gbvector *g = f;
  gbvector *gsyz = fsyz;
  mpz_t content;
  int leadsign;
  if (g != nullptr)
    {
      leadsign = mpz_sgn(g->coeff.get_mpz());
      mpz_init_set(content, g->coeff.get_mpz());
      g = g->next;
    }
  else if (gsyz != nullptr)
    {
      leadsign = mpz_sgn(gsyz->coeff.get_mpz());
      mpz_init_set(content, gsyz->coeff.get_mpz());
      gsyz = gsyz->next;
    }
  else
    return;
 
  lower_content_ZZ(g, content);
  lower_content_ZZ(gsyz, content);
 
  mpz_abs(content, content);
  if (mask_mpz_cmp_si(content, 1) == 0)
    {
      mpz_clear(content);
 
      if (leadsign < 0)
        {
          gbvector_negate_to(f);
          gbvector_negate_to(fsyz);
        }
      return;
    }
 
  if (leadsign < 0) mpz_neg(content, content);
  divide_coeff_exact_to_ZZ(f, content);
  divide_coeff_exact_to_ZZ(fsyz, content);
  if (use_denom)
    {
      denom = globalZZ->mult(denom, ring_elem(content));
    }
  mpz_clear(content);
}

References gbvector::coeff, divide_coeff_exact_to_ZZ(), gbvector_negate_to(), ring_elem::get_mpz(), globalZZ, lower_content_ZZ(), mask_mpz_cmp_si(), and gbvector::next.

Referenced by gbvector_remove_content().