gb_reduce()

void GB_comp::gb_reduce ( gbvector *& f, gbvector *& fsyz )

private

Definition at line 391 of file gb-homog2.cpp.

{
  if ((_strategy & STRATEGY_LONGPOLYNOMIALS) != 0)
    {
      gb_geo_reduce(f, fsyz);
      return;
    }
  gbvector head;
  gbvector *result = &head;
  result->next = nullptr;
 
  exponents_t div_totalexp = newarray_atomic(int, _M->n_vars());
  int count = 0;
  if (M2_gbTrace == 10)
    {
      buffer o;
      o << "reducing ";
      _GR->gbvector_text_out(o, _F, f);
      emit_line(o.str());
    }
  while (f != nullptr)
    {
      Bag *b;
      _GR->gbvector_get_lead_exponents(_F, f, div_totalexp);
      if (originalR->is_quotient_ring() &&
          originalR->get_quotient_monomials()->search_expvector(div_totalexp,
                                                                b))
        {
          const gbvector *g = originalR->quotient_gbvector(b->basis_elem());
          _GR->gbvector_reduce_lead_term(_F, _Fsyz, head.next, f, fsyz, g, nullptr);
          count++;
          _n_reductions++;
        }
      else if (_monideals[f->comp]->mi_search->search_expvector(div_totalexp,
                                                                b))
        {
          gb_elem *q = reinterpret_cast<gb_elem *>(b->basis_ptr());
          _GR->gbvector_reduce_lead_term(
              _F, _Fsyz, head.next, f, fsyz, q->f, q->fsyz);
          count++;
          _n_reductions++;
          if (M2_gbTrace == 10)
            {
              buffer o;
              o << "  reduced by ";
              _GR->gbvector_text_out(o, _F, q->f);
              o << newline;
              o << "    giving ";
              _GR->gbvector_text_out(o, _F, f);
              o << newline;
              emit(o.str());
            }
        }
      else
        {
          result->next = f;
          f = f->next;
          result = result->next;
          result->next = nullptr;
        }
    }
 
  if (M2_gbTrace >= 4)
    {
      buffer o;
      o << "." << count;
      emit_wrapped(o.str());
    }
  f = head.next;
  freemem(div_totalexp);
}

References _F, _Fsyz, _GR, _M, _n_reductions, _strategy, int_bag::basis_elem(), int_bag::basis_ptr(), gbvector::comp, emit(), emit_line(), emit_wrapped(), gb_elem::f, freemem(), gb_elem::fsyz, gb_geo_reduce(), M2_gbTrace, newarray_atomic, newline, gbvector::next, originalR, result(), buffer::str(), and STRATEGY_LONGPOLYNOMIALS.

Referenced by contains(), gen_step(), matrix_lift(), matrix_remainder(), and s_pair_step().