LocalMaximumSeedFinder.cc

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#include "LocalMaximumSeedFinder.h"

#include <algorithm>
#include <queue>
#include <cfloat>
#include "CommonTools/Utils/interface/DynArray.h"
#include "FWCore/MessageLogger/interface/MessageLogger.h"

namespace {
  const reco::PFRecHit::Neighbours  _noNeighbours(nullptr,0);
}

LocalMaximumSeedFinder::
LocalMaximumSeedFinder(const edm::ParameterSet& conf) : 
  SeedFinderBase(conf),   
  _nNeighbours(conf.getParameter<int>("nNeighbours")),
  _layerMap({ {"PS2",(int)PFLayer::PS2},
          {"PS1",(int)PFLayer::PS1},
          {"ECAL_ENDCAP",(int)PFLayer::ECAL_ENDCAP},
          {"ECAL_BARREL",(int)PFLayer::ECAL_BARREL},
          {"NONE",(int)PFLayer::NONE},
          {"HCAL_BARREL1",(int)PFLayer::HCAL_BARREL1},
          {"HCAL_BARREL2_RING0",(int)PFLayer::HCAL_BARREL2},
              // hack to deal with ring1 in HO 
          {"HCAL_BARREL2_RING1", 19}, 
          {"HCAL_ENDCAP",(int)PFLayer::HCAL_ENDCAP},
          {"HF_EM",(int)PFLayer::HF_EM},
          {"HF_HAD",(int)PFLayer::HF_HAD} }) {
  const std::vector<edm::ParameterSet>& thresholds =
    conf.getParameterSetVector("thresholdsByDetector");
  for( const auto& pset : thresholds ) {
    const std::string& det = pset.getParameter<std::string>("detector");
    const double& thresh_E = pset.getParameter<double>("seedingThreshold");
    const double& thresh_pT = pset.getParameter<double>("seedingThresholdPt");
    const double thresh_pT2 = thresh_pT*thresh_pT;
    auto entry = _layerMap.find(det);
    if( entry == _layerMap.end() ) {
      throw cms::Exception("InvalidDetectorLayer")
    << "Detector layer : " << det << " is not in the list of recognized"
    << " detector layers!";
    }
    _thresholds[entry->second+layerOffset]= 
            std::make_pair(thresh_E,thresh_pT2);
  }
}

// the starting state of seedable is all false!
void LocalMaximumSeedFinder::
findSeeds( const edm::Handle<reco::PFRecHitCollection>& input,
       const std::vector<bool>& mask,
       std::vector<bool>& seedable ) {

  auto nhits = input->size();
  initDynArray(bool,nhits,usable,true);
  //need to run over energy sorted rechits
  declareDynArray(float,nhits,energies);
  unInitDynArray(int,nhits,qst); // queue storage
  auto cmp = [&](int i, int j) { return energies[i] < energies[j]; };
  std::priority_queue<int, DynArray<int>, decltype(cmp)> ordered_hits(cmp,std::move(qst));

  for( unsigned i = 0; i < nhits; ++i ) {
    if( !mask[i] ) continue; // cannot seed masked objects
    const auto & maybeseed = (*input)[i];
    energies[i]=maybeseed.energy();
    int seedlayer = (int)maybeseed.layer();
    if( seedlayer == PFLayer::HCAL_BARREL2 &&
        std::abs(maybeseed.positionREP().eta()) > 0.34 ) {
      seedlayer = 19;
    }
    auto const & thresholds = _thresholds[seedlayer+layerOffset];
    if( maybeseed.energy() < thresholds.first ||
        maybeseed.pt2() < thresholds.second   ) usable[i] = false;
    if( !usable[i] ) continue;
    ordered_hits.push(i);
  }      


  while(!ordered_hits.empty() ) {
    auto idx = ordered_hits.top();
    ordered_hits.pop();  
    if( !usable[idx] ) continue;
    //get the neighbours of this seed
    const auto & maybeseed = (*input)[idx];
    reco::PFRecHit::Neighbours  myNeighbours;
    switch( _nNeighbours ) {
    case -1:
      myNeighbours = maybeseed.neighbours();
      break;
    case 0: // for HF clustering
      myNeighbours = _noNeighbours;
      break;
    case 4:
      myNeighbours = maybeseed.neighbours4();
      break;
    case 8:
      myNeighbours = maybeseed.neighbours8();
      break;
    default:
      throw cms::Exception("InvalidConfiguration")
    << "LocalMaximumSeedFinder only accepts nNeighbors = {-1,0,4,8}";    
    }
    seedable[idx] = true;
    for( auto neighbour : myNeighbours ) {
      if( !mask[neighbour] ) continue;
      if( energies[neighbour] > energies[idx] ) {
//        std::cout << "how this can be?" << std::endl;
    seedable[idx] = false;  
    break;
      }
    }
    if( seedable[idx] ) {
      for( auto neighbour : myNeighbours ) {
    usable[neighbour] = false;
      }
    }
  }

  LogDebug("LocalMaximumSeedFinder") << " found " << std::count(seedable.begin(),seedable.end(),true) << " seeds";

}