iquotient_and_sum()

void iquotient_and_sum ( MonomialIdeal & I, const_varpower m, MonomialIdeal *& quot, MonomialIdeal *& sum, stash * mi_stash )

static

Definition at line 267 of file hilb.cpp.

{
  gc_vector<Bag*> elems;
  sum = new MonomialIdeal(I.get_ring(), mi_stash);
  quot = new MonomialIdeal(I.get_ring(), mi_stash);
  Bag *bmin = new Bag();
  varpower::copy(m, bmin->monom());
  sum->insert_minimal(bmin);
  for (Bag& a : I)
    {
      Bag *b = new Bag();
      varpower::quotient(a.monom().data(), m, b->monom());
      if (varpower::divides(m, a.monom().data()))
        quot->insert_minimal(b);
      else
        {
          sum->insert_minimal(new Bag(0, a.monom()));
          elems.push_back(b);
        }
    }
 
  // Now we sort items in 'elems' so that we can insert as min gens into 'quot'
  std::vector<std::pair<int, int>> degs_and_indices;
  int count = 0;
  for (auto& b : elems)
    {
      int deg = varpower::simple_degree(b->monom().data());
      degs_and_indices.push_back(std::make_pair(deg, count));
      ++count;
    }
  std::stable_sort(degs_and_indices.begin(), degs_and_indices.end());
 
  for (auto p : degs_and_indices)
    {
      Bag* b = elems[p.second];
      Bag* b1; // not used here...
      if (quot->search(b->monom().data(), b1))
        delete b;
      else
        quot->insert_minimal(b);
    }
}

References ExponentList< int, true >::copy(), ExponentList< int, true >::divides(), MonomialIdeal::get_ring(), MonomialIdeal::insert_minimal(), int_bag::monom(), p, ExponentList< int, true >::quotient(), MonomialIdeal::search(), and ExponentList< int, true >::simple_degree().

Referenced by hilb_comp::recurse().