computeHomogeneous()

void NCGroebner::computeHomogeneous

(

int

softDegreeLimit

)

Definition at line 69 of file NCGroebner.cpp.

{
  size_t n_spairs = 0;
  while (!mOverlapTable.isFinished(softDegreeLimit))
    {
      auto degSet = mOverlapTable.nextDegreeOverlaps();
      auto toBeProcessed = degSet.second;
      if (M2_gbTrace >= 1)
        {
          buffer o;
          o << "[" << degSet.first << "](" << toBeProcessed->size() << ")";
          emit(o.str());
        }
      while(!toBeProcessed->empty())
        {
          auto overlap = toBeProcessed->front();
          //if this is a `real' overlap, and the overlap is not necessary, then move
          //on to the next overlap.
          if (std::get<1>(overlap) != -1 && !isOverlapNecessary(overlap))
            {
              toBeProcessed->pop_front();
              if (M2_gbTrace >= 3)
                {
                  std::cout << "Reduction avoided using 2nd criterion." << std::endl;
                  std::cout << "table after pop:";
                  mOverlapTable.dump(std::cout,true);
                }
              // TODO: is this logic correct?  Is the overlap actually skipped?
              continue;
            }
          auto overlapPoly = createOverlapPoly(overlap);
 
          n_spairs++;
          auto redOverlapPoly = twoSidedReduction(overlapPoly);
          delete overlapPoly;
 
          if (!freeAlgebra().is_zero(*redOverlapPoly))
            {
              addToGroebnerBasis(redOverlapPoly);
              autoreduceByLastElement();
              updateOverlaps(redOverlapPoly);
            }
          else
            {
              // if reduction is zero
              if (M2_gbTrace >= 4)
                {
                  std::cout << "Overlap " << overlap << " reduced to zero."
                            << std::endl;
                }
            }
          toBeProcessed->pop_front();
        }
      // remove the lowest degree overlaps from the overlap table
      mOverlapTable.removeLowestDegree();
    }
  if (M2_gbTrace >= 1)
    {
      buffer o;
      o << "[NCGB] number of spair reductions: " << n_spairs;
      emit_line(o.str());
    }
}

References addToGroebnerBasis(), autoreduceByLastElement(), createOverlapPoly(), emit(), emit_line(), freeAlgebra(), isOverlapNecessary(), M2_gbTrace, mOverlapTable, buffer::size(), buffer::str(), twoSidedReduction(), and updateOverlaps().

Referenced by compute().