PFAlgo.cc

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#include "FWCore/MessageLogger/interface/MessageLogger.h"
#include "RecoParticleFlow/PFProducer/interface/PFAlgo.h"
#include "RecoParticleFlow/PFProducer/interface/PFMuonAlgo.h"
#include "RecoParticleFlow/PFProducer/interface/PFElectronExtraEqual.h"
#include "RecoParticleFlow/PFTracking/interface/PFTrackAlgoTools.h"
 
#include "TDecompChol.h"
 
#include <numeric>
#include <fstream>
 
using namespace std;
using namespace reco;
 
PFAlgo::PFAlgo(double nSigmaECAL,
               double nSigmaHCAL,
               double nSigmaHFEM,
               double nSigmaHFHAD,
               std::vector<double> resolHF_square,
               PFEnergyCalibration& calibration,
               PFEnergyCalibrationHF& thepfEnergyCalibrationHF,
               const edm::ParameterSet& pset)
    : pfCandidates_(new PFCandidateCollection),
      nSigmaECAL_(nSigmaECAL),
      nSigmaHCAL_(nSigmaHCAL),
      nSigmaHFEM_(nSigmaHFEM),
      nSigmaHFHAD_(nSigmaHFHAD),
      resolHF_square_(resolHF_square),
      calibration_(calibration),
      thepfEnergyCalibrationHF_(thepfEnergyCalibrationHF),
      connector_() {
  const edm::ParameterSet pfMuonAlgoParams = pset.getParameter<edm::ParameterSet>("PFMuonAlgoParameters");
  bool postMuonCleaning = pset.getParameter<bool>("postMuonCleaning");
  pfmu_ = std::make_unique<PFMuonAlgo>(pfMuonAlgoParams, postMuonCleaning);
 
  // HF resolution parameters
  assert(resolHF_square_.size() == 3);  // make sure that stochastic, constant, noise (i.e. three) terms are specified.
 
  // Muon parameters
  muonHCAL_ = pset.getParameter<std::vector<double>>("muon_HCAL");
  muonECAL_ = pset.getParameter<std::vector<double>>("muon_ECAL");
  muonHO_ = pset.getParameter<std::vector<double>>("muon_HO");
  assert(muonHCAL_.size() == 2 && muonECAL_.size() == 2 && muonHO_.size() == 2);
  nSigmaTRACK_ = pset.getParameter<double>("nsigma_TRACK");
  ptError_ = pset.getParameter<double>("pt_Error");
  factors45_ = pset.getParameter<std::vector<double>>("factors_45");
  assert(factors45_.size() == 2);
 
  // Bad Hcal Track Parameters
  goodTrackDeadHcal_ptErrRel_ = pset.getParameter<double>("goodTrackDeadHcal_ptErrRel");
  goodTrackDeadHcal_chi2n_ = pset.getParameter<double>("goodTrackDeadHcal_chi2n");
  goodTrackDeadHcal_layers_ = pset.getParameter<uint32_t>("goodTrackDeadHcal_layers");
  goodTrackDeadHcal_validFr_ = pset.getParameter<double>("goodTrackDeadHcal_validFr");
  goodTrackDeadHcal_dxy_ = pset.getParameter<double>("goodTrackDeadHcal_dxy");
 
  goodPixelTrackDeadHcal_minEta_ = pset.getParameter<double>("goodPixelTrackDeadHcal_minEta");
  goodPixelTrackDeadHcal_maxPt_ = pset.getParameter<double>("goodPixelTrackDeadHcal_maxPt");
  goodPixelTrackDeadHcal_ptErrRel_ = pset.getParameter<double>("goodPixelTrackDeadHcal_ptErrRel");
  goodPixelTrackDeadHcal_chi2n_ = pset.getParameter<double>("goodPixelTrackDeadHcal_chi2n");
  goodPixelTrackDeadHcal_maxLost3Hit_ = pset.getParameter<int32_t>("goodPixelTrackDeadHcal_maxLost3Hit");
  goodPixelTrackDeadHcal_maxLost4Hit_ = pset.getParameter<int32_t>("goodPixelTrackDeadHcal_maxLost4Hit");
  goodPixelTrackDeadHcal_dxy_ = pset.getParameter<double>("goodPixelTrackDeadHcal_dxy");
  goodPixelTrackDeadHcal_dz_ = pset.getParameter<double>("goodPixelTrackDeadHcal_dz");
}
 
PFMuonAlgo* PFAlgo::getPFMuonAlgo() { return pfmu_.get(); }
 
void PFAlgo::setEGammaParameters(bool use_EGammaFilters, bool useProtectionsForJetMET) {
  useEGammaFilters_ = use_EGammaFilters;
 
  if (!useEGammaFilters_)
    return;
 
  useProtectionsForJetMET_ = useProtectionsForJetMET;
}
void PFAlgo::setEGammaCollections(const edm::View<reco::PFCandidate>& pfEgammaCandidates,
                                  const edm::ValueMap<reco::GsfElectronRef>& valueMapGedElectrons,
                                  const edm::ValueMap<reco::PhotonRef>& valueMapGedPhotons) {
  if (useEGammaFilters_) {
    pfEgammaCandidates_ = &pfEgammaCandidates;
    valueMapGedElectrons_ = &valueMapGedElectrons;
    valueMapGedPhotons_ = &valueMapGedPhotons;
  }
}
 
void PFAlgo::setPostHFCleaningParameters(bool postHFCleaning, const edm::ParameterSet& pfHFCleaningParams) {
  postHFCleaning_ = postHFCleaning;
  minHFCleaningPt_ = pfHFCleaningParams.getParameter<double>("minHFCleaningPt");
  minSignificance_ = pfHFCleaningParams.getParameter<double>("minSignificance");
  maxSignificance_ = pfHFCleaningParams.getParameter<double>("maxSignificance");
  minSignificanceReduction_ = pfHFCleaningParams.getParameter<double>("minSignificanceReduction");
  maxDeltaPhiPt_ = pfHFCleaningParams.getParameter<double>("maxDeltaPhiPt");
  minDeltaMet_ = pfHFCleaningParams.getParameter<double>("minDeltaMet");
}
 
void PFAlgo::setDisplacedVerticesParameters(bool rejectTracks_Bad,
                                            bool rejectTracks_Step45,
                                            bool usePFNuclearInteractions,
                                            bool usePFConversions,
                                            bool usePFDecays,
                                            double dptRel_DispVtx) {
  rejectTracks_Bad_ = rejectTracks_Bad;
  rejectTracks_Step45_ = rejectTracks_Step45;
  usePFNuclearInteractions_ = usePFNuclearInteractions;
  usePFConversions_ = usePFConversions;
  usePFDecays_ = usePFDecays;
  dptRel_DispVtx_ = dptRel_DispVtx;
}
 
void PFAlgo::setPFVertexParameters(bool useVertex, reco::VertexCollection const& primaryVertices) {
  useVertices_ = useVertex;
 
  //Set the vertices for muon cleaning
  pfmu_->setInputsForCleaning(primaryVertices);
 
  //Now find the primary vertex!
  bool primaryVertexFound = false;
  nVtx_ = primaryVertices.size();
  for (auto const& vertex : primaryVertices) {
    if (vertex.isValid() && (!vertex.isFake())) {
      primaryVertex_ = vertex;
      primaryVertexFound = true;
      break;
    }
  }
  //Use vertices if the user wants to but only if it exists a good vertex
  useVertices_ = useVertex && primaryVertexFound;
}
 
void PFAlgo::reconstructParticles(const reco::PFBlockHandle& blockHandle, PFEGammaFilters const* pfegamma) {
  auto const& blocks = *blockHandle;
 
  // reset output collection
  pfCandidates_->clear();
 
  LogTrace("PFAlgo|reconstructParticles")
      << "start of function PFAlgo::reconstructParticles, blocks.size()=" << blocks.size();
 
  // sort elements in three lists:
  std::list<reco::PFBlockRef> hcalBlockRefs;
  std::list<reco::PFBlockRef> ecalBlockRefs;
  std::list<reco::PFBlockRef> hoBlockRefs;
  std::list<reco::PFBlockRef> otherBlockRefs;
 
  for (unsigned i = 0; i < blocks.size(); ++i) {
    reco::PFBlockRef blockref = reco::PFBlockRef(blockHandle, i);
 
    const reco::PFBlock& block = *blockref;
    const edm::OwnVector<reco::PFBlockElement>& elements = block.elements();
 
    bool singleEcalOrHcal = false;
    if (elements.size() == 1) {
      if (elements[0].type() == reco::PFBlockElement::ECAL) {
        ecalBlockRefs.push_back(blockref);
        singleEcalOrHcal = true;
      }
      if (elements[0].type() == reco::PFBlockElement::HCAL) {
        hcalBlockRefs.push_back(blockref);
        singleEcalOrHcal = true;
      }
      if (elements[0].type() == reco::PFBlockElement::HO) {
        // Single HO elements are likely to be noise. Not considered for now.
        hoBlockRefs.push_back(blockref);
        singleEcalOrHcal = true;
      }
    }
 
    if (!singleEcalOrHcal) {
      otherBlockRefs.push_back(blockref);
    }
  }  //loop blocks
 
  LogTrace("PFAlgo|reconstructParticles")
      << "# Ecal blocks: " << ecalBlockRefs.size() << ", # Hcal blocks: " << hcalBlockRefs.size()
      << ", # HO blocks: " << hoBlockRefs.size() << ", # Other blocks: " << otherBlockRefs.size();
 
  // loop on blocks that are not single ecal,
  // and not single hcal.
 
  unsigned nblcks = 0;
  for (auto const& other : otherBlockRefs) {
    LogTrace("PFAlgo|reconstructParticles") << "processBlock, Block number " << nblcks++;
    processBlock(other, hcalBlockRefs, ecalBlockRefs, pfegamma);
  }
 
  std::list<reco::PFBlockRef> empty;
 
  unsigned hblcks = 0;
  // process remaining single hcal blocks
  for (auto const& hcal : hcalBlockRefs) {
    LogTrace("PFAlgo|reconstructParticles") << "processBlock, HCAL block number " << hblcks++;
    processBlock(hcal, empty, empty, pfegamma);
  }
 
  unsigned eblcks = 0;
  // process remaining single ecal blocks
  for (auto const& ecal : ecalBlockRefs) {
    LogTrace("PFAlgo|reconstructParticles") << "processBlock, ECAL block number " << eblcks++;
    processBlock(ecal, empty, empty, pfegamma);
  }
 
  // Post HF Cleaning
  pfCleanedCandidates_.clear();
  // Check if the post HF Cleaning was requested - if not, do nothing
  if (postHFCleaning_) {
    postCleaning();
  }
 
  //Muon post cleaning
  pfmu_->postClean(pfCandidates_.get());
 
  //Add Missing muons
  if (muonHandle_.isValid())
    pfmu_->addMissingMuons(muonHandle_, pfCandidates_.get());
 
  LogTrace("PFAlgo|reconstructParticles")
      << "end of function PFAlgo::reconstructParticles, pfCandidates_->size()=" << pfCandidates_->size();
}
 
void PFAlgo::egammaFilters(const reco::PFBlockRef& blockref,
                           std::vector<bool>& active,
                           PFEGammaFilters const* pfegamma) {
  // const edm::ValueMap<reco::GsfElectronRef> & myGedElectronValMap(*valueMapGedElectrons_);
 
  unsigned int negmcandidates = pfEgammaCandidates_->size();
  LogTrace("PFAlgo|egammaFilters") << "start of function PFAlgo::egammaFilters(), negmcandidates=" << negmcandidates;
 
  for (unsigned int ieg = 0; ieg < negmcandidates; ++ieg) {
    //      const reco::PFCandidate & egmcand((*pfEgammaCandidates_)[ieg]);
    reco::PFCandidateRef pfEgmRef = pfEgammaCandidates_->refAt(ieg).castTo<reco::PFCandidateRef>();
 
    const PFCandidate::ElementsInBlocks& theElements = (*pfEgmRef).elementsInBlocks();
    PFCandidate::ElementsInBlocks::const_iterator iegfirst = theElements.begin();
    bool sameBlock = false;
    bool isGoodElectron = false;
    bool isGoodPhoton = false;
    bool isPrimaryElectron = false;
    if (iegfirst->first == blockref)
      sameBlock = true;
    if (sameBlock) {
      LogTrace("PFAlgo|egammaFilters") << " I am in looping on EGamma Candidates: pt " << (*pfEgmRef).pt()
                                       << " eta,phi " << (*pfEgmRef).eta() << ", " << (*pfEgmRef).phi() << " charge "
                                       << (*pfEgmRef).charge();
 
      if ((*pfEgmRef).gsfTrackRef().isNonnull()) {
        reco::GsfElectronRef gedEleRef = (*valueMapGedElectrons_)[pfEgmRef];
        if (gedEleRef.isNonnull()) {
          isGoodElectron = pfegamma->passElectronSelection(*gedEleRef, *pfEgmRef, nVtx_);
          isPrimaryElectron = pfegamma->isElectron(*gedEleRef);
          if (isGoodElectron)
            LogTrace("PFAlgo|egammaFilters")
                << "** Good Electron, pt " << gedEleRef->pt() << " eta, phi " << gedEleRef->eta() << ", "
                << gedEleRef->phi() << " charge " << gedEleRef->charge() << " isPrimary " << isPrimaryElectron
                << " isoDr03 "
                << (gedEleRef->dr03TkSumPt() + gedEleRef->dr03EcalRecHitSumEt() + gedEleRef->dr03HcalTowerSumEt())
                << " mva_isolated " << gedEleRef->mva_Isolated() << " mva_e_pi " << gedEleRef->mva_e_pi();
        }
      }
      if ((*pfEgmRef).superClusterRef().isNonnull()) {
        reco::PhotonRef gedPhoRef = (*valueMapGedPhotons_)[pfEgmRef];
        if (gedPhoRef.isNonnull()) {
          isGoodPhoton = pfegamma->passPhotonSelection(*gedPhoRef);
          if (isGoodPhoton)
            LogTrace("PFAlgo|egammaFilters") << "** Good Photon, pt " << gedPhoRef->pt() << " eta, phi "
                                             << gedPhoRef->eta() << ", " << gedPhoRef->phi() << endl;
        }
      }
    }  // end sameBlock
 
    if (isGoodElectron && isGoodPhoton) {
      if (isPrimaryElectron)
        isGoodPhoton = false;
      else
        isGoodElectron = false;
    }
 
    // isElectron
    if (isGoodElectron) {
      reco::GsfElectronRef gedEleRef = (*valueMapGedElectrons_)[pfEgmRef];
      reco::PFCandidate myPFElectron = *pfEgmRef;
      // run protections
      bool lockTracks = false;
      bool isSafe = true;
      if (useProtectionsForJetMET_) {
        lockTracks = true;
        isSafe = pfegamma->isElectronSafeForJetMET(*gedEleRef, myPFElectron, primaryVertex_, lockTracks);
      }
 
      if (isSafe) {
        reco::PFCandidate::ParticleType particleType = reco::PFCandidate::e;
        myPFElectron.setParticleType(particleType);
        myPFElectron.setCharge(gedEleRef->charge());
        myPFElectron.setP4(gedEleRef->p4());
        myPFElectron.set_mva_e_pi(gedEleRef->mva_e_pi());
        myPFElectron.set_mva_Isolated(gedEleRef->mva_Isolated());
 
        LogTrace("PFAlgo|egammaFilters") << " PFAlgo: found an electron with NEW EGamma code ";
        LogTrace("PFAlgo|egammaFilters") << " myPFElectron: pt " << myPFElectron.pt() << " eta,phi "
                                         << myPFElectron.eta() << ", " << myPFElectron.phi() << " mva "
                                         << myPFElectron.mva_e_pi() << " charge " << myPFElectron.charge();
 
        LogTrace("PFAlgo|egammaFilters") << " THE BLOCK " << *blockref;
        for (auto const& eb : theElements) {
          active[eb.second] = false;
          LogTrace("PFAlgo|egammaFilters") << " Elements used " << eb.second;
        }
 
        // The electron is considered safe for JetMET and the additional tracks pointing to it are locked
        if (lockTracks) {
          const PFCandidate::ElementsInBlocks& extraTracks = myPFElectron.egammaExtraRef()->extraNonConvTracks();
          for (auto const& trk : extraTracks) {
            LogTrace("PFAlgo|egammaFilters") << " Extra locked track " << trk.second;
            active[trk.second] = false;
          }
        }
 
        LogTrace("PFAlgo|egammaFilters") << "Creating PF electron: pt=" << myPFElectron.pt()
                                         << " eta=" << myPFElectron.eta() << " phi=" << myPFElectron.phi();
        pfCandidates_->push_back(myPFElectron);
 
      } else {
        LogTrace("PFAlgo|egammaFilters") << "PFAlgo: Electron DISCARDED, NOT SAFE FOR JETMET ";
      }
    }  //isGoodElectron
 
    if (isGoodPhoton) {
      reco::PhotonRef gedPhoRef = (*valueMapGedPhotons_)[pfEgmRef];
      reco::PFCandidate myPFPhoton = *pfEgmRef;
      bool isSafe = true;
      if (useProtectionsForJetMET_) {
        isSafe = pfegamma->isPhotonSafeForJetMET(*gedPhoRef, myPFPhoton);
      }
 
      if (isSafe) {
        reco::PFCandidate::ParticleType particleType = reco::PFCandidate::gamma;
        myPFPhoton.setParticleType(particleType);
        myPFPhoton.setCharge(0);
        myPFPhoton.set_mva_nothing_gamma(1.);
        ::math::XYZPoint v(primaryVertex_.x(), primaryVertex_.y(), primaryVertex_.z());
        myPFPhoton.setVertex(v);
        myPFPhoton.setP4(gedPhoRef->p4());
        LogTrace("PFAlgo|egammaFilters") << " PFAlgo: found a photon with NEW EGamma code ";
        LogTrace("PFAlgo|egammaFilters") << " myPFPhoton: pt " << myPFPhoton.pt() << " eta,phi " << myPFPhoton.eta()
                                         << ", " << myPFPhoton.phi() << " charge " << myPFPhoton.charge();
 
        // Lock all the elements
        LogTrace("PFAlgo|egammaFilters") << " THE BLOCK " << *blockref;
        for (auto const& eb : theElements) {
          active[eb.second] = false;
          LogTrace("PFAlgo|egammaFilters") << " Elements used " << eb.second;
        }
        LogTrace("PFAlgo|egammaFilters") << "Creating PF photon: pt=" << myPFPhoton.pt() << " eta=" << myPFPhoton.eta()
                                         << " phi=" << myPFPhoton.phi();
        pfCandidates_->push_back(myPFPhoton);
 
      }  // end isSafe
    }    // end isGoodPhoton
  }      // end loop on EGM candidates
  LogTrace("PFAlgo|egammaFilters") << "end of function PFAlgo::egammaFilters";
}
 
void PFAlgo::conversionAlgo(const edm::OwnVector<reco::PFBlockElement>& elements, std::vector<bool>& active) {
  LogTrace("PFAlgo|conversionAlgo") << "start of function PFAlgo::conversionAlgo(), elements.size()="
                                    << elements.size();
  for (unsigned iEle = 0; iEle < elements.size(); iEle++) {
    PFBlockElement::Type type = elements[iEle].type();
    if (type == PFBlockElement::TRACK) {
      LogTrace("PFAlgo|conversionAlgo") << "elements[" << iEle << "].type() == TRACK, active[" << iEle
                                        << "]=" << active[iEle];
      if (elements[iEle].trackRef()->algo() == reco::TrackBase::conversionStep) {
        active[iEle] = false;
      }
      if (elements[iEle].trackRef()->quality(reco::TrackBase::highPurity)) {
        LogTrace("PFAlgo|conversionAlgo") << "Track is high purity";
        continue;
      }
      const auto* trackRef = dynamic_cast<const reco::PFBlockElementTrack*>((&elements[iEle]));
      if (!(trackRef->trackType(reco::PFBlockElement::T_FROM_GAMMACONV))) {
        LogTrace("PFAlgo|conversionAlgo") << "!trackType(T_FROM_GAMMACONV)";
        continue;
      }
      if (!elements[iEle].convRefs().empty()) {
        active[iEle] = false;
      }
      LogTrace("PFAlgo|conversionAlgo") << "active[iEle=" << iEle << "]=" << active[iEle];
    }
  }
  LogTrace("PFAlgo|conversionAlgo") << "end of function PFAlgo::conversionAlgo";
}
 
bool PFAlgo::recoTracksNotHCAL(const reco::PFBlock& block,
                               reco::PFBlock::LinkData& linkData,
                               const edm::OwnVector<reco::PFBlockElement>& elements,
                               const reco::PFBlockRef& blockref,
                               std::vector<bool>& active,
                               bool goodTrackDeadHcal,
                               bool hasDeadHcal,
                               unsigned int iTrack,
                               std::multimap<double, unsigned>& ecalElems,
                               reco::TrackRef& trackRef) {
  LogTrace("PFAlgo|recoTracksNotHCAL") << "start of function PFAlgo::recoTracksNotHCAL(), now dealing with tracks "
                                          "linked to no HCAL clusters. Was HCal active? "
                                       << (!hasDeadHcal);
  // vector<unsigned> elementIndices;
  // elementIndices.push_back(iTrack);
 
  // The track momentum
  double trackMomentum = elements[iTrack].trackRef()->p();
  LogTrace("PFAlgo|recoTracksNotHCAL") << elements[iTrack];
 
  // Is it a "tight" muon ? In that case assume no
  //Track momentum corresponds to the calorimeter
  //energy for now
  bool thisIsAMuon = PFMuonAlgo::isMuon(elements[iTrack]);
  if (thisIsAMuon)
    trackMomentum = 0.;
 
  // If it is not a muon check if Is it a fake track ?
  //Michalis: I wonder if we should convert this to dpt/pt?
  if (!thisIsAMuon && elements[iTrack].trackRef()->ptError() > ptError_) {
    double deficit = trackMomentum;
    double resol = neutralHadronEnergyResolution(trackMomentum, elements[iTrack].trackRef()->eta());
    resol *= trackMomentum;
 
    if (!ecalElems.empty()) {
      unsigned thisEcal = ecalElems.begin()->second;
      reco::PFClusterRef clusterRef = elements[thisEcal].clusterRef();
      bool useCluster = true;
      if (hasDeadHcal) {
        std::multimap<double, unsigned> sortedTracks;
        block.associatedElements(
            thisEcal, linkData, sortedTracks, reco::PFBlockElement::TRACK, reco::PFBlock::LINKTEST_ALL);
        useCluster = (sortedTracks.begin()->second == iTrack);
      }
      if (useCluster) {
        deficit -= clusterRef->energy();
        resol = neutralHadronEnergyResolution(trackMomentum, clusterRef->positionREP().Eta());
        resol *= trackMomentum;
      }
    }
 
    bool isPrimary = isFromSecInt(elements[iTrack], "primary");
 
    if (deficit > nSigmaTRACK_ * resol && !isPrimary && !goodTrackDeadHcal) {
      active[iTrack] = false;
      LogTrace("PFAlgo|recoTracksNotHCAL")
          << elements[iTrack] << std::endl
          << " deficit " << deficit << " > " << nSigmaTRACK_ << " x " << resol << " track pt " << trackRef->pt()
          << " +- " << trackRef->ptError() << " layers valid " << trackRef->hitPattern().trackerLayersWithMeasurement()
          << ", lost " << trackRef->hitPattern().trackerLayersWithoutMeasurement(HitPattern::TRACK_HITS)
          << ", lost outer " << trackRef->hitPattern().trackerLayersWithoutMeasurement(HitPattern::MISSING_OUTER_HITS)
          << ", lost inner " << trackRef->hitPattern().trackerLayersWithoutMeasurement(HitPattern::MISSING_INNER_HITS)
          << "(valid fraction " << trackRef->validFraction() << ")"
          << " chi2/ndf " << trackRef->normalizedChi2() << " |dxy| "
          << std::abs(trackRef->dxy(primaryVertex_.position())) << " +- " << trackRef->dxyError() << " |dz| "
          << std::abs(trackRef->dz(primaryVertex_.position())) << " +- " << trackRef->dzError()
          << "is probably a fake (1) --> lock the track";
      return true;
    }
  }  // !thisIsaMuon
 
  // Create a track candidate
  // unsigned tmpi = reconstructTrack( elements[iTrack] );
  //active[iTrack] = false;
  std::vector<unsigned> tmpi;
  std::vector<unsigned> kTrack;
 
  // Some cleaning : secondary tracks without calo's and large momentum must be fake
  double dpt = trackRef->ptError();
 
  if (rejectTracks_Step45_ && ecalElems.empty() && trackMomentum > 30. && dpt > 0.5 &&
      (PFTrackAlgoTools::step45(trackRef->algo()) && !goodTrackDeadHcal)) {
    double dptRel = dpt / trackRef->pt() * 100;
    bool isPrimaryOrSecondary = isFromSecInt(elements[iTrack], "all");
 
    if (isPrimaryOrSecondary && dptRel < dptRel_DispVtx_) {
      return true;
    };
    unsigned nHits = elements[iTrack].trackRef()->hitPattern().trackerLayersWithMeasurement();
    unsigned int NLostHit = trackRef->hitPattern().trackerLayersWithoutMeasurement(HitPattern::TRACK_HITS);
 
    LogTrace("PFAlgo|recoTracksNotHCAL") << "A track (algo = " << trackRef->algo() << ") with momentum "
                                         << trackMomentum << " / " << elements[iTrack].trackRef()->pt() << " +/- "
                                         << dpt << " / " << elements[iTrack].trackRef()->eta()
                                         << " without any link to ECAL/HCAL and with " << nHits << " (" << NLostHit
                                         << ") hits (lost hits) has been cleaned";
 
    active[iTrack] = false;
    return true;
  }  //rejectTracks_Step45_ && ...
 
  tmpi.push_back(reconstructTrack(elements[iTrack]));
 
  kTrack.push_back(iTrack);
  active[iTrack] = false;
 
  // No ECAL cluster either ... continue...
  if (ecalElems.empty()) {
    (*pfCandidates_)[tmpi[0]].setEcalEnergy(0., 0.);
    (*pfCandidates_)[tmpi[0]].setHcalEnergy(0., 0.);
    (*pfCandidates_)[tmpi[0]].setHoEnergy(0., 0.);
    (*pfCandidates_)[tmpi[0]].setPs1Energy(0);
    (*pfCandidates_)[tmpi[0]].setPs2Energy(0);
    (*pfCandidates_)[tmpi[0]].addElementInBlock(blockref, kTrack[0]);
    return true;
  }
 
  // Look for closest ECAL cluster
  const unsigned int thisEcal = ecalElems.begin()->second;
  reco::PFClusterRef clusterRef = elements[thisEcal].clusterRef();
  LogTrace("PFAlgo|recoTracksNotHCAL") << " is associated to " << elements[thisEcal];
 
  // Set ECAL energy for muons
  if (thisIsAMuon) {
    (*pfCandidates_)[tmpi[0]].setEcalEnergy(clusterRef->energy(), std::min(clusterRef->energy(), muonECAL_[0]));
    (*pfCandidates_)[tmpi[0]].setHcalEnergy(0., 0.);
    (*pfCandidates_)[tmpi[0]].setHoEnergy(0., 0.);
    (*pfCandidates_)[tmpi[0]].setPs1Energy(0);
    (*pfCandidates_)[tmpi[0]].setPs2Energy(0);
    (*pfCandidates_)[tmpi[0]].addElementInBlock(blockref, kTrack[0]);
  }
 
  double slopeEcal = 1.;
  bool connectedToEcal = false;
  unsigned iEcal = 99999;
  double calibEcal = 0.;
  double calibHcal = 0.;
  double totalEcal = thisIsAMuon ? -muonECAL_[0] : 0.;
 
  // Consider charged particles closest to the same ECAL cluster
  std::multimap<double, unsigned> sortedTracks;
  block.associatedElements(thisEcal, linkData, sortedTracks, reco::PFBlockElement::TRACK, reco::PFBlock::LINKTEST_ALL);
  LogTrace("PFAlgo|recoTracksNotHCAL") << "the closest ECAL cluster, id " << thisEcal << ", has " << sortedTracks.size()
                                       << " associated tracks, now processing them. ";
 
  if (hasDeadHcal && !sortedTracks.empty()) {
    // GP: only allow the ecal cluster closest to this track to be considered
    LogTrace("PFAlgo|recoTracksNotHCAL") << " the closest track to ECAL " << thisEcal << " is "
                                         << sortedTracks.begin()->second << " (distance " << sortedTracks.begin()->first
                                         << ")";
    if (sortedTracks.begin()->second != iTrack) {
      LogTrace("PFAlgo|recoTracksNotHCAL")
          << " the closest track to ECAL " << thisEcal << " is " << sortedTracks.begin()->second
          << " which is not the one being processed. Will skip ECAL linking for this track";
      (*pfCandidates_)[tmpi[0]].setEcalEnergy(0., 0.);
      (*pfCandidates_)[tmpi[0]].setHcalEnergy(0., 0.);
      (*pfCandidates_)[tmpi[0]].setHoEnergy(0., 0.);
      (*pfCandidates_)[tmpi[0]].setPs1Energy(0);
      (*pfCandidates_)[tmpi[0]].setPs2Energy(0);
      (*pfCandidates_)[tmpi[0]].addElementInBlock(blockref, kTrack[0]);
      return true;
    } else {
      LogTrace("PFAlgo|recoTracksNotHCAL")
          << " the closest track to ECAL " << thisEcal << " is " << sortedTracks.begin()->second
          << " which is the one being processed. Will skip ECAL linking for all other track";
      sortedTracks.clear();
    }
  }
 
  for (auto const& trk : sortedTracks) {
    unsigned jTrack = trk.second;
 
    // Don't consider already used tracks
    if (!active[jTrack])
      continue;
 
    // The loop is on the other tracks !
    if (jTrack == iTrack)
      continue;
 
    // Check if the ECAL cluster closest to this track is
    // indeed the current ECAL cluster. Only tracks not
    // linked to an HCAL cluster are considered here
    // (GP: this is because if there's a jTrack linked
    // to the same Ecal cluster and that also has an Hcal link
    // we would have also linked iTrack to that Hcal above)
    std::multimap<double, unsigned> sortedECAL;
    block.associatedElements(jTrack, linkData, sortedECAL, reco::PFBlockElement::ECAL, reco::PFBlock::LINKTEST_ALL);
    if (sortedECAL.begin()->second != thisEcal)
      continue;
 
    // Check if this track is a muon
    bool thatIsAMuon = PFMuonAlgo::isMuon(elements[jTrack]);
    LogTrace("PFAlgo|recoTracksNotHCAL") << " found track " << jTrack << (thatIsAMuon ? " (muon) " : " (non-muon)")
                                         << ", with distance = " << sortedECAL.begin()->first;
 
    // Check if this track is not a fake
    bool rejectFake = false;
    reco::TrackRef trackRef = elements[jTrack].trackRef();
    if (!thatIsAMuon && trackRef->ptError() > ptError_) {
      // GP: FIXME this selection should be adapted depending on hasDeadHcal
      //     but we don't know if jTrack is linked to a dead Hcal or not
      double deficit = trackMomentum + trackRef->p() - clusterRef->energy();
      double resol =
          nSigmaTRACK_ * neutralHadronEnergyResolution(trackMomentum + trackRef->p(), clusterRef->positionREP().Eta());
      resol *= (trackMomentum + trackRef->p());
      if (deficit > nSigmaTRACK_ * resol && !goodTrackDeadHcal) {
        rejectFake = true;
        kTrack.push_back(jTrack);
        active[jTrack] = false;
        LogTrace("PFAlgo|recoTracksNotHCAL")
            << elements[jTrack] << std::endl
            << "is probably a fake (2) --> lock the track"
            << "(trackMomentum = " << trackMomentum << ", clusterEnergy = " << clusterRef->energy()
            << ", deficit = " << deficit << " > " << nSigmaTRACK_ << " x " << resol
            << " assuming neutralHadronEnergyResolution "
            << neutralHadronEnergyResolution(trackMomentum + trackRef->p(), clusterRef->positionREP().Eta()) << ") ";
      }
    }
    if (rejectFake)
      continue;
 
    // Otherwise, add this track momentum to the total track momentum
    /* */
    // reco::TrackRef trackRef = elements[jTrack].trackRef();
    if (!thatIsAMuon) {
      LogTrace("PFAlgo|recoTracksNotHCAL") << "Track momentum increased from " << trackMomentum << " GeV ";
      trackMomentum += trackRef->p();
      LogTrace("PFAlgo|recoTracksNotHCAL") << "to " << trackMomentum << " GeV.";
      LogTrace("PFAlgo|recoTracksNotHCAL") << "with " << elements[jTrack];
    } else {
      totalEcal -= muonECAL_[0];
      totalEcal = std::max(totalEcal, 0.);
    }
 
    // And create a charged particle candidate !
 
    tmpi.push_back(reconstructTrack(elements[jTrack]));
 
    kTrack.push_back(jTrack);
    active[jTrack] = false;
 
    if (thatIsAMuon) {
      (*pfCandidates_)[tmpi.back()].setEcalEnergy(clusterRef->energy(), std::min(clusterRef->energy(), muonECAL_[0]));
      (*pfCandidates_)[tmpi.back()].setHcalEnergy(0., 0.);
      (*pfCandidates_)[tmpi.back()].setHoEnergy(0., 0.);
      (*pfCandidates_)[tmpi.back()].setPs1Energy(0);
      (*pfCandidates_)[tmpi.back()].setPs2Energy(0);
      (*pfCandidates_)[tmpi.back()].addElementInBlock(blockref, kTrack.back());
    }
  }
 
  LogTrace("PFAlgo|recoTracksNotHCAL") << "Loop over all associated ECAL clusters";
  // Loop over all ECAL linked clusters ordered by increasing distance.
  for (auto const& ecal : ecalElems) {
    const unsigned index = ecal.second;
    const PFBlockElement::Type type = elements[index].type();
    assert(type == PFBlockElement::ECAL);
    LogTrace("PFAlgo|recoTracksNotHCAL") << elements[index];
 
    // Just skip clusters already taken
    if (!active[index]) {
      LogTrace("PFAlgo|recoTracksNotHCAL") << "is not active  - ignore ";
      continue;
    }
 
    // Just skip this cluster if it's closer to another track
    block.associatedElements(index, linkData, sortedTracks, reco::PFBlockElement::TRACK, reco::PFBlock::LINKTEST_ALL);
 
    const bool skip = std::none_of(
        kTrack.begin(), kTrack.end(), [&](unsigned iTrack) { return sortedTracks.begin()->second == iTrack; });
 
    if (skip) {
      LogTrace("PFAlgo|recoTracksNotHCAL") << "is closer to another track - ignore ";
      continue;
    }
 
    // The corresponding PFCluster and energy
    const reco::PFClusterRef clusterRef = elements[index].clusterRef();
    assert(!clusterRef.isNull());
 
    LogTrace("PFAlgo|recoTracksNotHCAL") << "Ecal cluster with raw energy = " << clusterRef->energy()
                                         << " linked with distance = " << ecal.first;
 
    // Check the presence of preshower clusters in the vicinity
    // Preshower cluster closer to another ECAL cluster are ignored.
    //JOSH: This should use the association map already produced by the cluster corrector for consistency,
    //but should be ok for now
    vector<double> ps1Ene{0.};
    associatePSClusters(index, reco::PFBlockElement::PS1, block, elements, linkData, active, ps1Ene);
    vector<double> ps2Ene{0.};
    associatePSClusters(index, reco::PFBlockElement::PS2, block, elements, linkData, active, ps2Ene);
 
    // KH: use raw ECAL energy for PF hadron calibration. use calibrated ECAL energy when adding PF photons
    const double ecalEnergy = clusterRef->energy();
    const double ecalEnergyCalibrated = clusterRef->correctedEnergy();  // calibrated based on the egamma hypothesis
    LogTrace("PFAlgo|recoTracksNotHCAL") << "Corrected ECAL(+PS) energy = " << ecalEnergy;
 
    // Since the electrons were found beforehand, this track must be a hadron. Calibrate
    // the energy under the hadron hypothesis.
    totalEcal += ecalEnergy;
    const double previousCalibEcal = calibEcal;
    const double previousSlopeEcal = slopeEcal;
    calibEcal = std::max(totalEcal, 0.);
    calibHcal = 0.;
    calibration_.energyEmHad(
        trackMomentum, calibEcal, calibHcal, clusterRef->positionREP().Eta(), clusterRef->positionREP().Phi());
    if (totalEcal > 0.)
      slopeEcal = calibEcal / totalEcal;
 
    LogTrace("PFAlgo|recoTracksNotHCAL") << "The total calibrated energy so far amounts to = " << calibEcal
                                         << " (slope = " << slopeEcal << ")";
 
    // Stop the loop when adding more ECAL clusters ruins the compatibility
    if (connectedToEcal && calibEcal - trackMomentum >= 0.) {
      // if ( connectedToEcal && calibEcal - trackMomentum >=
      //     nSigmaECAL_*neutralHadronEnergyResolution(trackMomentum,clusterRef->positionREP().Eta())  ) {
      calibEcal = previousCalibEcal;
      slopeEcal = previousSlopeEcal;
      totalEcal = calibEcal / slopeEcal;
 
      // Turn this last cluster in a photon
      // (The PS clusters are already locked in "associatePSClusters")
      active[index] = false;
 
      // Find the associated tracks
      std::multimap<double, unsigned> assTracks;
      block.associatedElements(index, linkData, assTracks, reco::PFBlockElement::TRACK, reco::PFBlock::LINKTEST_ALL);
 
      auto& ecalCand = (*pfCandidates_)[reconstructCluster(
          *clusterRef, ecalEnergyCalibrated)];  // KH: use the PF ECAL cluster calibrated energy
      ecalCand.setEcalEnergy(clusterRef->energy(), ecalEnergyCalibrated);
      ecalCand.setHcalEnergy(0., 0.);
      ecalCand.setHoEnergy(0., 0.);
      ecalCand.setPs1Energy(ps1Ene[0]);
      ecalCand.setPs2Energy(ps2Ene[0]);
      ecalCand.addElementInBlock(blockref, index);
      // Check that there is at least one track
      if (!assTracks.empty()) {
        ecalCand.addElementInBlock(blockref, assTracks.begin()->second);
 
        // Assign the position of the track at the ECAL entrance
        const ::math::XYZPointF& chargedPosition =
            dynamic_cast<const reco::PFBlockElementTrack*>(&elements[assTracks.begin()->second])
                ->positionAtECALEntrance();
        ecalCand.setPositionAtECALEntrance(chargedPosition);
      }
      break;
    }
 
    // Lock used clusters.
    connectedToEcal = true;
    iEcal = index;
    active[index] = false;
    for (unsigned ic : tmpi)
      (*pfCandidates_)[ic].addElementInBlock(blockref, iEcal);
 
  }  // Loop ecal elements
 
  bool bNeutralProduced = false;
 
  // Create a photon if the ecal energy is too large
  if (connectedToEcal) {
    reco::PFClusterRef pivotalRef = elements[iEcal].clusterRef();
 
    double neutralEnergy = calibEcal - trackMomentum;
 
    /*
    // Check if there are other tracks linked to that ECAL
    for(IE ie = sortedTracks.begin(); ie != sortedTracks.end() && neutralEnergy > 0; ++ie ) {
      unsigned jTrack = ie->second;
 
      // The loop is on the other tracks !
      if ( jTrack == iTrack ) continue;
 
      // Check if the ECAL closest to this track is the current ECAL
      // Otherwise ignore this track in the neutral energy determination
      std::multimap<double, unsigned> sortedECAL;
      block.associatedElements( jTrack,  linkData,
                    sortedECAL,
                    reco::PFBlockElement::ECAL,
                    reco::PFBlock::LINKTEST_ALL );
      if ( sortedECAL.begin()->second != iEcal ) continue;
 
      // Check if this track is also linked to an HCAL
      // (in which case it goes to the next loop and is ignored here)
      std::multimap<double, unsigned> sortedHCAL;
      block.associatedElements( jTrack,  linkData,
                    sortedHCAL,
                    reco::PFBlockElement::HCAL,
                    reco::PFBlock::LINKTEST_ALL );
      if ( sortedHCAL.size() ) continue;
 
      // Otherwise, subtract this track momentum from the ECAL energy
      reco::TrackRef trackRef = elements[jTrack].trackRef();
      neutralEnergy -= trackRef->p();
 
    } // End other tracks
    */
 
    // Add a photon if the energy excess is large enough
    double resol = neutralHadronEnergyResolution(trackMomentum, pivotalRef->positionREP().Eta());
    resol *= trackMomentum;
    if (neutralEnergy > std::max(0.5, nSigmaECAL_ * resol)) {
      neutralEnergy /= slopeEcal;
      unsigned tmpj = reconstructCluster(*pivotalRef, neutralEnergy);
      (*pfCandidates_)[tmpj].setEcalEnergy(pivotalRef->energy(), neutralEnergy);
      (*pfCandidates_)[tmpj].setHcalEnergy(0., 0.);
      (*pfCandidates_)[tmpj].setHoEnergy(0., 0.);
      (*pfCandidates_)[tmpj].setPs1Energy(0.);
      (*pfCandidates_)[tmpj].setPs2Energy(0.);
      (*pfCandidates_)[tmpj].addElementInBlock(blockref, iEcal);
      bNeutralProduced = true;
      for (unsigned ic = 0; ic < kTrack.size(); ++ic)
        (*pfCandidates_)[tmpj].addElementInBlock(blockref, kTrack[ic]);
    }  // End neutral energy
 
    // Set elements in blocks and ECAL energies to all tracks
    for (unsigned ic = 0; ic < tmpi.size(); ++ic) {
      // Skip muons
      if ((*pfCandidates_)[tmpi[ic]].particleId() == reco::PFCandidate::mu)
        continue;
 
      double fraction = trackMomentum > 0 ? (*pfCandidates_)[tmpi[ic]].trackRef()->p() / trackMomentum : 0;
      double ecalCal = bNeutralProduced ? (calibEcal - neutralEnergy * slopeEcal) * fraction : calibEcal * fraction;
      double ecalRaw = totalEcal * fraction;
 
      LogTrace("PFAlgo|recoTracksNotHCAL")
          << "The fraction after photon supression is " << fraction << " calibrated ecal = " << ecalCal;
 
      (*pfCandidates_)[tmpi[ic]].setEcalEnergy(ecalRaw, ecalCal);
      (*pfCandidates_)[tmpi[ic]].setHcalEnergy(0., 0.);
      (*pfCandidates_)[tmpi[ic]].setHoEnergy(0., 0.);
      (*pfCandidates_)[tmpi[ic]].setPs1Energy(0);
      (*pfCandidates_)[tmpi[ic]].setPs2Energy(0);
      (*pfCandidates_)[tmpi[ic]].addElementInBlock(blockref, kTrack[ic]);
    }
 
  }  // End connected ECAL
 
  // Fill the element_in_block for tracks that are eventually linked to no ECAL clusters at all.
  for (unsigned ic = 0; ic < tmpi.size(); ++ic) {
    const PFCandidate& pfc = (*pfCandidates_)[tmpi[ic]];
    const PFCandidate::ElementsInBlocks& eleInBlocks = pfc.elementsInBlocks();
    if (eleInBlocks.empty()) {
      LogTrace("PFAlgo|recoTracksNotHCAL") << "Single track / Fill element in block! ";
      (*pfCandidates_)[tmpi[ic]].addElementInBlock(blockref, kTrack[ic]);
    }
  }
  LogTrace("PFAlgo|recoTracksNotHCAL") << "end of function PFAlgo::recoTracksNotHCAL";
  return false;
}
 
//Check if the track is a primary track of a secondary interaction
//If that is the case reconstruct a charged hadron only using that
//track
bool PFAlgo::checkAndReconstructSecondaryInteraction(const reco::PFBlockRef& blockref,
                                                     const edm::OwnVector<reco::PFBlockElement>& elements,
                                                     bool isActive,
                                                     int iElement) {
  bool ret = isActive;
  if (isActive && isFromSecInt(elements[iElement], "primary")) {
    bool isPrimaryTrack =
        elements[iElement].displacedVertexRef(PFBlockElement::T_TO_DISP)->displacedVertexRef()->isTherePrimaryTracks();
    if (isPrimaryTrack) {
      LogTrace("PFAlgo|elementLoop") << "Primary Track reconstructed alone";
 
      unsigned tmpi = reconstructTrack(elements[iElement]);
      (*pfCandidates_)[tmpi].addElementInBlock(blockref, iElement);
      ret = false;
    }
  }
 
  return ret;
}
 
bool PFAlgo::checkHasDeadHcal(const std::multimap<double, unsigned>& hcalElems, const std::vector<bool>& deadArea) {
  // there's 3 possible options possible here, in principle:
  //    1) flag everything that may be associated to a dead hcal marker
  //    2) flag everything whose closest hcal link is a dead hcal marker
  //    3) flag only things that are linked only to dead hcal marker
  // in our first test we go for (2)
  //--- option (1) --
  //bool hasDeadHcal = false;
  //for (auto it = hcalElems.begin(), ed = hcalElems.end(); it != ed; /*NOTE NO ++it HERE */ ) {
  //    if (deadArea[it->second]) { hasDeadHcal = true; it = hcalElems.erase(it); } // std::multimap::erase returns iterator to next
  //    else ++it;
  //}
  //--- option (2) --
  bool hasDeadHcal = false;
  if (!hcalElems.empty() && deadArea[hcalElems.begin()->second]) {
    hasDeadHcal = true;
  }
  //--- option (3) --
  //bool hasDeadHcal = true;
  //for (auto it = hcalElems.begin(), ed = hcalElems.end(); it != ed; /*NOTE NO ++it HERE */ ) {
  //    if (deadArea[it->second]) { it = hcalElems.erase(it); } // std::multimap::erase returns iterator to next
  //    else { hasDeadHcal = false; }
  //}
  return hasDeadHcal;
}
 
// for tracks with bad Hcal, check the track quality
bool PFAlgo::checkGoodTrackDeadHcal(const reco::TrackRef& trackRef, bool hasDeadHcal) {
  bool goodTrackDeadHcal = false;
  if (hasDeadHcal) {
    goodTrackDeadHcal = (trackRef->ptError() < goodTrackDeadHcal_ptErrRel_ * trackRef->pt() &&
                         trackRef->normalizedChi2() < goodTrackDeadHcal_chi2n_ &&
                         trackRef->hitPattern().trackerLayersWithMeasurement() >= goodTrackDeadHcal_layers_ &&
                         trackRef->validFraction() > goodTrackDeadHcal_validFr_ &&
                         std::abs(trackRef->dxy(primaryVertex_.position())) < goodTrackDeadHcal_dxy_);
    // now we add an extra block for tracks at high |eta|
    if (!goodTrackDeadHcal && std::abs(trackRef->eta()) > goodPixelTrackDeadHcal_minEta_ &&  // high eta
        trackRef->hitPattern().pixelLayersWithMeasurement() >= 3 &&                          // pixel track
        trackRef->hitPattern().trackerLayersWithoutMeasurement(HitPattern::TRACK_HITS) == 0 &&
        trackRef->hitPattern().trackerLayersWithoutMeasurement(HitPattern::MISSING_INNER_HITS) == 0 &&
        trackRef->hitPattern().trackerLayersWithoutMeasurement(HitPattern::MISSING_OUTER_HITS) <=
            (trackRef->hitPattern().pixelLayersWithMeasurement() > 3 ? goodPixelTrackDeadHcal_maxLost4Hit_
                                                                     : goodPixelTrackDeadHcal_maxLost3Hit_) &&
        trackRef->normalizedChi2() < goodPixelTrackDeadHcal_chi2n_ &&  // tighter cut
        std::abs(trackRef->dxy(primaryVertex_.position())) < goodPixelTrackDeadHcal_dxy_ &&
        std::abs(trackRef->dz(primaryVertex_.position())) < goodPixelTrackDeadHcal_dz_ &&
        trackRef->ptError() < goodPixelTrackDeadHcal_ptErrRel_ * trackRef->pt() &&  // sanity
        trackRef->pt() < goodPixelTrackDeadHcal_maxPt_) {                           // sanity
      goodTrackDeadHcal = true;
      // FIXME: may decide to do something to the track pT
    }
    //if (!goodTrackDeadHcal && trackRef->hitPattern().trackerLayersWithMeasurement() == 4 && trackRef->validFraction() == 1
    LogTrace("PFAlgo|elementLoop")
        << " track pt " << trackRef->pt() << " +- " << trackRef->ptError() << " layers valid "
        << trackRef->hitPattern().trackerLayersWithMeasurement() << ", lost "
        << trackRef->hitPattern().trackerLayersWithoutMeasurement(HitPattern::TRACK_HITS) << ", lost outer "
        << trackRef->hitPattern().trackerLayersWithoutMeasurement(HitPattern::MISSING_OUTER_HITS) << ", lost inner "
        << trackRef->hitPattern().trackerLayersWithoutMeasurement(HitPattern::MISSING_INNER_HITS) << "(valid fraction "
        << trackRef->validFraction() << ")"
        << " chi2/ndf " << trackRef->normalizedChi2() << " |dxy| " << std::abs(trackRef->dxy(primaryVertex_.position()))
        << " +- " << trackRef->dxyError() << " |dz| " << std::abs(trackRef->dz(primaryVertex_.position())) << " +- "
        << trackRef->dzError() << (goodTrackDeadHcal ? " passes " : " fails ") << "quality cuts";
  }
  return goodTrackDeadHcal;
}
 
void PFAlgo::relinkTrackToHcal(const reco::PFBlock& block,
                               std::multimap<double, unsigned>& ecalElems,
                               std::multimap<double, unsigned>& hcalElems,
                               const std::vector<bool>& active,
                               reco::PFBlock::LinkData& linkData,
                               unsigned int iTrack) {
  unsigned ntt = 1;
  unsigned index = ecalElems.begin()->second;
  std::multimap<double, unsigned> sortedTracks;
  block.associatedElements(index, linkData, sortedTracks, reco::PFBlockElement::TRACK, reco::PFBlock::LINKTEST_ALL);
  LogTrace("PFAlgo|elementLoop") << "The closest ECAL cluster is linked to " << sortedTracks.size()
                                 << " tracks, with distance = " << ecalElems.begin()->first;
 
  LogTrace("PFAlgo|elementLoop") << "Looping over sortedTracks";
  // Loop over all tracks
  for (auto const& trk : sortedTracks) {
    unsigned jTrack = trk.second;
    LogTrace("PFAlgo|elementLoop") << "jTrack=" << jTrack;
    // Track must be active
    if (!active[jTrack])
      continue;
    LogTrace("PFAlgo|elementLoop") << "active[jTrack]=" << active[jTrack];
 
    // The loop is on the other tracks !
    if (jTrack == iTrack)
      continue;
    LogTrace("PFAlgo|elementLoop") << "skipping jTrack=" << jTrack << " for same iTrack";
 
    // Check if the ECAL closest to this track is the current ECAL
    // Otherwise ignore this track in the neutral energy determination
    std::multimap<double, unsigned> sortedECAL;
    block.associatedElements(jTrack, linkData, sortedECAL, reco::PFBlockElement::ECAL, reco::PFBlock::LINKTEST_ALL);
    if (sortedECAL.begin()->second != index)
      continue;
    LogTrace("PFAlgo|elementLoop") << "  track " << jTrack << " with closest ECAL identical ";
 
    // Check if this track is also linked to an HCAL
    std::multimap<double, unsigned> sortedHCAL;
    block.associatedElements(jTrack, linkData, sortedHCAL, reco::PFBlockElement::HCAL, reco::PFBlock::LINKTEST_ALL);
    if (sortedHCAL.empty())
      continue;
    LogTrace("PFAlgo|elementLoop") << "  and with an HCAL cluster " << sortedHCAL.begin()->second;
    ntt++;
 
    // In that case establish a link with the first track
    block.setLink(iTrack, sortedHCAL.begin()->second, sortedECAL.begin()->first, linkData, PFBlock::LINKTEST_RECHIT);
 
  }  // End other tracks
 
  // Redefine HCAL elements
  block.associatedElements(iTrack, linkData, hcalElems, reco::PFBlockElement::HCAL, reco::PFBlock::LINKTEST_ALL);
 
  if (!hcalElems.empty())
    LogTrace("PFAlgo|elementLoop") << "Track linked back to HCAL due to ECAL sharing with other tracks";
}
 
void PFAlgo::elementLoop(const reco::PFBlock& block,
                         reco::PFBlock::LinkData& linkData,
                         const edm::OwnVector<reco::PFBlockElement>& elements,
                         std::vector<bool>& active,
                         const reco::PFBlockRef& blockref,
                         ElementIndices& inds,
                         std::vector<bool>& deadArea) {
  LogTrace("PFAlgo|elementLoop") << "start of function PFAlgo::elementLoop, elements.size()" << elements.size();
 
  for (unsigned iEle = 0; iEle < elements.size(); iEle++) {
    PFBlockElement::Type type = elements[iEle].type();
 
    LogTrace("PFAlgo|elementLoop") << "elements[iEle=" << iEle << "]=" << elements[iEle];
    //only process TRACK elements, but fill the ElementIndices vector with indices for all elements.
    //Mark the active & deadArea for bad HCAL
    auto ret_decideType = decideType(elements, type, active, inds, deadArea, iEle);
    if (ret_decideType == 1) {
      LogTrace("PFAlgo|elementLoop") << "ret_decideType==1, continuing";
      continue;
    }
    LogTrace("PFAlgo|elementLoop") << "ret_decideType=" << ret_decideType << " type=" << type;
 
    active[iEle] = checkAndReconstructSecondaryInteraction(blockref, elements, active[iEle], iEle);
 
    if (!active[iEle]) {
      LogTrace("PFAlgo|elementLoop") << "Already used by electrons, muons, conversions";
      continue;
    }
 
    reco::TrackRef trackRef = elements[iEle].trackRef();
    assert(!trackRef.isNull());
 
    LogTrace("PFAlgo|elementLoop") << "PFAlgo:processBlock"
                                   << " trackIs.size()=" << inds.trackIs.size()
                                   << " ecalIs.size()=" << inds.ecalIs.size() << " hcalIs.size()=" << inds.hcalIs.size()
                                   << " hoIs.size()=" << inds.hoIs.size() << " hfEmIs.size()=" << inds.hfEmIs.size()
                                   << " hfHadIs.size()=" << inds.hfHadIs.size();
 
    // look for associated elements of all types
    //COLINFEB16
    // all types of links are considered.
    // the elements are sorted by increasing distance
    std::multimap<double, unsigned> ecalElems;
    block.associatedElements(iEle, linkData, ecalElems, reco::PFBlockElement::ECAL, reco::PFBlock::LINKTEST_ALL);
 
    std::multimap<double, unsigned> hcalElems;
    block.associatedElements(iEle, linkData, hcalElems, reco::PFBlockElement::HCAL, reco::PFBlock::LINKTEST_ALL);
 
    std::multimap<double, unsigned> hfEmElems;
    std::multimap<double, unsigned> hfHadElems;
    block.associatedElements(iEle, linkData, hfEmElems, reco::PFBlockElement::HFEM, reco::PFBlock::LINKTEST_ALL);
    block.associatedElements(iEle, linkData, hfHadElems, reco::PFBlockElement::HFHAD, reco::PFBlock::LINKTEST_ALL);
 
    LogTrace("PFAlgo|elementLoop") << "\tTrack " << iEle << " is linked to " << ecalElems.size() << " ecal and "
                                   << hcalElems.size() << " hcal and " << hfEmElems.size() << " hfEm and "
                                   << hfHadElems.size() << " hfHad elements";
 
#ifdef EDM_ML_DEBUG
    for (const auto& pair : ecalElems) {
      LogTrace("PFAlgo|elementLoop") << "ecal: dist " << pair.first << "\t elem " << pair.second;
    }
    for (const auto& pair : hcalElems) {
      LogTrace("PFAlgo|elementLoop") << "hcal: dist " << pair.first << "\t elem " << pair.second
                                     << (deadArea[pair.second] ? "  DEAD AREA MARKER" : "");
    }
#endif
 
    const bool hasDeadHcal = checkHasDeadHcal(hcalElems, deadArea);
    if (hasDeadHcal) {
      hcalElems.clear();
    }
    const bool goodTrackDeadHcal = checkGoodTrackDeadHcal(trackRef, hasDeadHcal);
 
    // When a track has no HCAL cluster linked, but another track is linked to the same
    // ECAL cluster and an HCAL cluster, link the track to the HCAL cluster for
    // later analysis
    if (hcalElems.empty() && !ecalElems.empty() && !hasDeadHcal) {
      relinkTrackToHcal(block, ecalElems, hcalElems, active, linkData, iEle);
    }
 
    //MICHELE
    //TEMPORARY SOLUTION FOR ELECTRON REJECTION IN PFTAU
    //COLINFEB16
    // in case particle flow electrons are not reconstructed,
    // the mva_e_pi of the charged hadron will be set to 1
    // if a GSF element is associated to the current TRACK element
    // This information will be used in the electron rejection for tau ID.
    std::multimap<double, unsigned> gsfElems;
    block.associatedElements(iEle, linkData, gsfElems, reco::PFBlockElement::GSF);
 
    if (hcalElems.empty()) {
      LogTrace("PFAlgo|elementLoop") << "no hcal element connected to track " << iEle;
    }
 
    // will now loop on associated elements ...
    bool hcalFound = false;
    bool hfhadFound = false;
 
    LogTrace("PFAlgo|elementLoop") << "now looping on elements associated to the track: ecalElems";
 
    // ... first on associated ECAL elements
    // Check if there is still a free ECAL for this track
    for (auto const& ecal : ecalElems) {
      unsigned index = ecal.second;
      // Sanity checks and optional printout
      PFBlockElement::Type type = elements[index].type();
#ifdef EDM_ML_DEBUG
      double dist = ecal.first;
      LogTrace("PFAlgo|elementLoop") << "\telement " << elements[index] << " linked with distance = " << dist;
      if (!active[index])
        LogTrace("PFAlgo|elementLoop") << "This ECAL is already used - skip it";
#endif
      assert(type == PFBlockElement::ECAL);
 
      // This ECAL is not free (taken by an electron?) - just skip it
      if (!active[index])
        continue;
 
      // Flag ECAL clusters for which the corresponding track is not linked to an HCAL cluster
 
      //reco::PFClusterRef clusterRef = elements[index].clusterRef();
      //assert( !clusterRef.isNull() );
      if (!hcalElems.empty())
        LogTrace("PFAlgo|elementLoop") << "\t\tat least one hcal element connected to the track."
                                       << " Sparing Ecal cluster for the hcal loop";
 
    }  //loop print ecal elements
 
    // tracks which are not linked to an HCAL (or HFHAD)
    // are reconstructed now.
 
    if (hcalElems.empty() && hfHadElems.empty()) {
      auto ret_continue = recoTracksNotHCAL(
          block, linkData, elements, blockref, active, goodTrackDeadHcal, hasDeadHcal, iEle, ecalElems, trackRef);
      if (ret_continue) {
        continue;
      }
    }  // end if( hcalElems.empty() && hfHadElems.empty() )
 
    // In case several HCAL elements are linked to this track,
    // unlinking all of them except the closest.
    for (auto const& hcal : hcalElems) {
      unsigned index = hcal.second;
 
      PFBlockElement::Type type = elements[index].type();
 
#ifdef EDM_ML_DEBUG
      double dist = block.dist(iEle, index, linkData, reco::PFBlock::LINKTEST_ALL);
      LogTrace("PFAlgo|elementLoop") << "\telement " << elements[index] << " linked with distance " << dist;
#endif
      assert(type == PFBlockElement::HCAL);
 
      // all hcal clusters except the closest
      // will be unlinked from the track
      if (!hcalFound) {  // closest hcal
        LogTrace("PFAlgo|elementLoop") << "\t\tclosest hcal cluster, doing nothing";
 
        hcalFound = true;
 
        // active[index] = false;
        // hcalUsed.push_back( index );
      } else {  // other associated hcal
        // unlink from the track
        LogTrace("PFAlgo|elementLoop") << "\t\tsecondary hcal cluster. unlinking";
        block.setLink(iEle, index, -1., linkData, PFBlock::LINKTEST_RECHIT);
      }
    }  //loop hcal elements
 
    // ---Same for HFHAD---
    // In case several HFHAD elements are linked to this track,
    // unlinking all of them except the closest.
    for (auto const& hfhad : hfHadElems) {
      unsigned index = hfhad.second;
 
      PFBlockElement::Type type = elements[index].type();
 
#ifdef EDM_ML_DEBUG
      double dist = block.dist(iEle, index, linkData, reco::PFBlock::LINKTEST_ALL);
      LogTrace("PFAlgo|elementLoop") << "\telement " << elements[index] << " linked with distance " << dist;
#endif
      assert(type == PFBlockElement::HFHAD);
 
      // all hfhad clusters except the closest
      // will be unlinked from the track
      if (!hfhadFound) {  // closest hfhad
        LogTrace("PFAlgo|elementLoop") << "\t\tclosest hfhad cluster, doing nothing";
 
        hfhadFound = true;
 
      } else {  // other associated hfhad
        // unlink from the track
        LogTrace("PFAlgo|elementLoop") << "\t\tsecondary hfhad cluster. unlinking";
        block.setLink(iEle, index, -1., linkData, PFBlock::LINKTEST_RECHIT);
      }
    }  //loop hfhad elements
 
    LogTrace("PFAlgo|elementLoop") << "end of loop over iEle";
  }  // end of outer loop on elements iEle of any type
  LogTrace("PFAlgo|elementLoop") << "end of function PFAlgo::elementLoop";
}
 
//Arranges the PFBlock elements according to type into the ElementIndices output vector.
//Also checks for dead HCAL area and updates the active and deadArea vectors.
//Returns 0 for elements of TRACK type, 1 otherwise
int PFAlgo::decideType(const edm::OwnVector<reco::PFBlockElement>& elements,
                       const reco::PFBlockElement::Type type,
                       std::vector<bool>& active,
                       ElementIndices& inds,
                       std::vector<bool>& deadArea,
                       unsigned int iEle) {
  switch (type) {
    case PFBlockElement::TRACK:
      if (active[iEle]) {
        inds.trackIs.push_back(iEle);
        LogTrace("PFAlgo|decideType") << "TRACK, stored index, continue";
      }
      break;
    case PFBlockElement::ECAL:
      if (active[iEle]) {
        inds.ecalIs.push_back(iEle);
        LogTrace("PFAlgo|decideType") << "ECAL, stored index, continue";
      }
      return 1;  //continue
    case PFBlockElement::HCAL:
      if (active[iEle]) {
        if (elements[iEle].clusterRef()->flags() & reco::CaloCluster::badHcalMarker) {
          LogTrace("PFAlgo|decideType") << "HCAL DEAD AREA: remember and skip.";
          active[iEle] = false;
          deadArea[iEle] = true;
          return 1;  //continue
        }
        inds.hcalIs.push_back(iEle);
        LogTrace("PFAlgo|decideType") << "HCAL, stored index, continue";
      }
      return 1;  //continue
    case PFBlockElement::HO:
      if (useHO_) {
        if (active[iEle]) {
          inds.hoIs.push_back(iEle);
          LogTrace("PFAlgo|decideType") << "HO, stored index, continue";
        }
      }
      return 1;  //continue
    case PFBlockElement::HFEM:
      if (active[iEle]) {
        inds.hfEmIs.push_back(iEle);
        LogTrace("PFAlgo|decideType") << "HFEM, stored index, continue";
      }
      return 1;  //continue
    case PFBlockElement::HFHAD:
      if (active[iEle]) {
        inds.hfHadIs.push_back(iEle);
        LogTrace("PFAlgo|decideType") << "HFHAD, stored index, continue";
      }
      return 1;  //continue
    default:
      return 1;  //continue
  }
  LogTrace("PFAlgo|decideType") << "Did not match type to anything, return 0";
  return 0;
}
 
void PFAlgo::createCandidatesHF(const reco::PFBlock& block,
                                reco::PFBlock::LinkData& linkData,
                                const edm::OwnVector<reco::PFBlockElement>& elements,
                                std::vector<bool>& active,
                                const reco::PFBlockRef& blockref,
                                ElementIndices& inds) {
  LogTrace("PFAlgo|createCandidatesHF") << "starting function PFAlgo::createCandidatesHF";
 
  bool trackInBlock = !inds.trackIs.empty();
  // inds.trackIs can be empty, even if there are tracks in this block,
  // but what we want to check is if this block has any track including inactive ones
  if (!trackInBlock)
    for (unsigned iEle = 0; iEle < elements.size(); iEle++) {
      PFBlockElement::Type type = elements[iEle].type();
      if (type == PFBlockElement::TRACK) {
        trackInBlock = true;
        break;
      }
    }
  // there is at least one HF element in this block.
  // in case of no track, all elements must be HF
  if (!trackInBlock)
    assert(inds.hfEmIs.size() + inds.hfHadIs.size() == elements.size());
 
  //
  // Dealing with a block with at least one track
  // Occasionally, there are only inactive tracks and multiple HF clusters. Consider such blocks too.
  //
  if (trackInBlock) {  // count any tracks (not only active tracks)
    // sorted tracks associated with a HfHad cluster
    std::multimap<double, unsigned> sortedTracks;
    std::multimap<double, unsigned> sortedTracksActive;  // only active ones
    // HfEms associated with tracks linked to a HfHad cluster
    std::multimap<unsigned, std::pair<double, unsigned>> associatedHfEms;
    // Temporary map for HfEm satellite clusters
    std::multimap<double, std::pair<unsigned, double>> hfemSatellites;
 
    //
    // Loop over active HfHad clusters
    //
    for (unsigned iHfHad : inds.hfHadIs) {
      PFBlockElement::Type type = elements[iHfHad].type();
      assert(type == PFBlockElement::HFHAD);
 
      PFClusterRef hclusterRef = elements[iHfHad].clusterRef();
      assert(!hclusterRef.isNull());
 
      sortedTracks.clear();
      sortedTracksActive.clear();
      associatedHfEms.clear();
      hfemSatellites.clear();
 
      // Look for associated tracks
      block.associatedElements(
          iHfHad, linkData, sortedTracks, reco::PFBlockElement::TRACK, reco::PFBlock::LINKTEST_ALL);
 
      LogTrace("PFAlgo|createCandidatesHF") << "elements[" << iHfHad << "]=" << elements[iHfHad];
 
      if (sortedTracks.empty()) {
        LogTrace("PFAlgo|createCandidatesHCF") << "\tno associated tracks, keep for later";
        continue;
      }
 
      // Lock the HFHAD cluster
      active[iHfHad] = false;
 
      LogTrace("PFAlgo|createCandidatesHF") << sortedTracks.size() << " associated tracks:";
 
      double totalChargedMomentum = 0.;
      double sumpError2 = 0.;
 
      //
      // Loop over all tracks associated to this HFHAD cluster
      //
      for (auto const& trk : sortedTracks) {
        unsigned iTrack = trk.second;
 
        // Check the track has not already been used
        if (!active[iTrack])
          continue;
        // Sanity check 1
        PFBlockElement::Type type = elements[iTrack].type();
        assert(type == reco::PFBlockElement::TRACK);
        // Sanity check 2
        reco::TrackRef trackRef = elements[iTrack].trackRef();
        assert(!trackRef.isNull());
 
        // Introduce tracking errors
        double trackMomentum = trackRef->p();
        totalChargedMomentum += trackMomentum;
 
        // Also keep the total track momentum error for comparison with the calo energy
        double dp = trackRef->qoverpError() * trackMomentum * trackMomentum;
        sumpError2 += dp * dp;
 
        // Store active tracks for 2nd loop to create charged hadrons
        sortedTracksActive.emplace(trk);
 
        // look for HFEM elements associated to iTrack (associated to iHfHad)
        std::multimap<double, unsigned> sortedHfEms;
        block.associatedElements(
            iTrack, linkData, sortedHfEms, reco::PFBlockElement::HFEM, reco::PFBlock::LINKTEST_ALL);
 
        LogTrace("PFAlgo|createCandidatesHF") << "number of HfEm elements linked to this track: " << sortedHfEms.size();
 
        bool connectedToHfEm = false;  // Will become true if there is at least one HFEM cluster connected
 
        //
        // Loop over all HFEM clusters connected to iTrack
        //
        for (auto const& hfem : sortedHfEms) {
          unsigned iHfEm = hfem.second;
          double dist = hfem.first;
 
          // Ignore HFEM cluters already used
          if (!active[iHfEm]) {
            LogTrace("PFAlgo|createCandidatesHF") << "cluster locked";
            continue;
          }
 
          // Sanity checks
          PFBlockElement::Type type = elements[iHfEm].type();
          assert(type == PFBlockElement::HFEM);
          PFClusterRef eclusterRef = elements[iHfEm].clusterRef();
          assert(!eclusterRef.isNull());
 
          // Check if this HFEM is not closer to another track - ignore it in that case
          std::multimap<double, unsigned> sortedTracksHfEm;
          block.associatedElements(
              iHfEm, linkData, sortedTracksHfEm, reco::PFBlockElement::TRACK, reco::PFBlock::LINKTEST_ALL);
          unsigned jTrack = sortedTracksHfEm.begin()->second;
          if (jTrack != iTrack)
            continue;
 
          double distHfEm = block.dist(jTrack, iHfEm, linkData, reco::PFBlock::LINKTEST_ALL);
          double hfemEnergy = eclusterRef->energy();
 
          if (!connectedToHfEm) {  // This is the closest HFEM cluster - will add its energy later
 
            LogTrace("PFAlgo|createCandidatesHF") << "closest: " << elements[iHfEm];
            connectedToHfEm = true;
            std::pair<unsigned, double> satellite(iHfEm, hfemEnergy);
            hfemSatellites.emplace(-1., satellite);
 
          } else {  // Keep satellite clusters for later
 
            // KH: same as above.
            std::pair<unsigned, double> satellite(iHfEm, hfemEnergy);
            hfemSatellites.emplace(dist, satellite);
          }
 
          std::pair<double, unsigned> associatedHfEm(distHfEm, iHfEm);
          associatedHfEms.emplace(iTrack, associatedHfEm);
 
        }  // End loop hfem associated to iTrack
      }    // sortedTracks
 
      // HfHad energy
      double uncalibratedenergyHfHad = hclusterRef->energy();
      double energyHfHad = uncalibratedenergyHfHad;
      if (thepfEnergyCalibrationHF_.getcalibHF_use()) {
        energyHfHad = thepfEnergyCalibrationHF_.energyHad(  // HAD only calibration
            uncalibratedenergyHfHad,
            hclusterRef->positionREP().Eta(),
            hclusterRef->positionREP().Phi());
      }
      double calibFactorHfHad = (uncalibratedenergyHfHad > 0.) ? energyHfHad / uncalibratedenergyHfHad : 1.;
 
      // HfEm energy
      double energyHfEmTmp = 0.;
      double uncalibratedenergyHfEmTmp = 0.;
      double energyHfEm = 0.;
      double uncalibratedenergyHfEm = 0.;
 
      // estimated HF resolution and track p error
      double caloResolution = hfEnergyResolution(totalChargedMomentum);
      caloResolution *= totalChargedMomentum;
      double totalError = sqrt(caloResolution * caloResolution + sumpError2);
      double nsigmaHFEM = nSigmaHFEM(totalChargedMomentum);
      double nsigmaHFHAD = nSigmaHFHAD(totalChargedMomentum);
 
      // Handle case that no active track gets associated to HfHad cluster
      if (sortedTracksActive.empty()) {
        // look for HFEM elements associated to iHfHad
        std::multimap<double, unsigned> sortedHfEms;
        std::multimap<double, unsigned> sortedHfEmsActive;
        block.associatedElements(
            iHfHad, linkData, sortedHfEms, reco::PFBlockElement::HFEM, reco::PFBlock::LINKTEST_ALL);
        //
        // If iHfHad is connected to HFEM cluster, Loop over all of them
        //
        if (!sortedHfEms.empty()) {
          for (auto const& hfem : sortedHfEms) {
            unsigned iHfEm = hfem.second;
            // Ignore HFEM cluters already used
            if (!active[iHfEm])
              continue;
            sortedHfEmsActive.emplace(hfem);
            PFClusterRef eclusterRef = elements[iHfEm].clusterRef();
            assert(!eclusterRef.isNull());
            double hfemEnergy = eclusterRef->energy();
            uncalibratedenergyHfEm += hfemEnergy;
            energyHfEm = uncalibratedenergyHfEm;
            if (thepfEnergyCalibrationHF_.getcalibHF_use()) {
              energyHfEm = thepfEnergyCalibrationHF_.energyEmHad(
                  uncalibratedenergyHfEm, 0.0, eclusterRef->positionREP().Eta(), eclusterRef->positionREP().Phi());
              energyHfHad = thepfEnergyCalibrationHF_.energyEmHad(
                  0.0, uncalibratedenergyHfHad, hclusterRef->positionREP().Eta(), hclusterRef->positionREP().Phi());
            }  // calib true
          }    // loop over sortedHfEm
        }      // if !sortedHfEms.empty()
        //
        // Create HF candidates
        unsigned tmpi = reconstructCluster(*hclusterRef, energyHfEm + energyHfHad);
        (*pfCandidates_)[tmpi].setHcalEnergy(uncalibratedenergyHfHad, energyHfHad);
        (*pfCandidates_)[tmpi].setEcalEnergy(uncalibratedenergyHfEm, energyHfEm);
        (*pfCandidates_)[tmpi].addElementInBlock(blockref, iHfHad);
        for (auto const& hfem : sortedHfEmsActive) {
          unsigned iHfEm = hfem.second;
          (*pfCandidates_)[tmpi].addElementInBlock(blockref, iHfEm);
          active[iHfEm] = false;
        }
 
      }  // if sortedTracksActive.empty() ends
      //
      // Active tracks are associated.
      // Create HFHAD candidates from excess energy w.r.t. tracks
      else if ((energyHfHad - totalChargedMomentum) > nsigmaHFHAD * totalError) {  // HfHad is excessive
        assert(energyHfEm == 0.);
        // HfHad candidate from excess
        double energyHfHadExcess = max(energyHfHad - totalChargedMomentum, 0.);
        double uncalibratedenergyHfHadExcess = energyHfHadExcess / calibFactorHfHad;
        unsigned tmpi = reconstructCluster(*hclusterRef, energyHfHadExcess);
        (*pfCandidates_)[tmpi].setHcalEnergy(uncalibratedenergyHfHadExcess, energyHfHadExcess);
        (*pfCandidates_)[tmpi].setEcalEnergy(0., 0.);
        (*pfCandidates_)[tmpi].addElementInBlock(blockref, iHfHad);
        energyHfHad = max(energyHfHad - energyHfHadExcess, 0.);
        uncalibratedenergyHfHad = max(uncalibratedenergyHfHad - uncalibratedenergyHfHadExcess, 0.);
      }
      //
      // If there is a room for HFEM satellites to get associated,
      // loop over all HFEM satellites, starting for the closest to the various tracks
      // and adding other satellites until saturation of the total track momentum
      //
      else {
        for (auto const& hfemSatellite : hfemSatellites) {
          //
          uncalibratedenergyHfEmTmp += std::get<1>(hfemSatellite.second);  // KH: raw HFEM energy
          energyHfEmTmp = uncalibratedenergyHfEmTmp;
          double energyHfHadTmp = uncalibratedenergyHfHad;  // now to test hfhad calibration with EM+HAD cases
          unsigned iHfEm = std::get<0>(hfemSatellite.second);
          PFClusterRef eclusterRef = elements[iHfEm].clusterRef();
          assert(!eclusterRef.isNull());
          if (thepfEnergyCalibrationHF_.getcalibHF_use()) {
            energyHfEmTmp = thepfEnergyCalibrationHF_.energyEmHad(
                uncalibratedenergyHfEmTmp, 0.0, eclusterRef->positionREP().Eta(), eclusterRef->positionREP().Phi());
            energyHfHadTmp = thepfEnergyCalibrationHF_.energyEmHad(
                0.0, uncalibratedenergyHfHad, hclusterRef->positionREP().Eta(), hclusterRef->positionREP().Phi());
          }
 
          double caloEnergyTmp = energyHfEmTmp + energyHfHadTmp;
          double calibFactorHfEm = (uncalibratedenergyHfEmTmp > 0.) ? energyHfEmTmp / uncalibratedenergyHfEmTmp : 1.;
 
          // Continue looping until all closest clusters are exhausted and as long as
          // the calorimetric energy does not saturate the total momentum.
          if (hfemSatellite.first < 0. || caloEnergyTmp < totalChargedMomentum) {
            LogTrace("PFAlgo|createCandidatesHF")
                << "\t\t\tactive, adding " << std::get<1>(hfemSatellite.second) << " to HFEM energy, and locking";
            active[std::get<0>(hfemSatellite.second)] = false;
            // HfEm is excessive (possible for the first hfemSatellite)
            if (hfemSatellite.first < 0. && (caloEnergyTmp - totalChargedMomentum) > nsigmaHFEM * totalError) {
              // HfEm candidate from excess
              double energyHfEmExcess = max(caloEnergyTmp - totalChargedMomentum, 0.);
              double uncalibratedenergyHfEmExcess = energyHfEmExcess / calibFactorHfEm;
              unsigned tmpi = reconstructCluster(*eclusterRef, energyHfEmExcess);
              (*pfCandidates_)[tmpi].setEcalEnergy(uncalibratedenergyHfEmExcess, energyHfEmExcess);
              (*pfCandidates_)[tmpi].setHcalEnergy(0, 0.);
              (*pfCandidates_)[tmpi].addElementInBlock(blockref, iHfEm);
              energyHfEmTmp = max(energyHfEmTmp - energyHfEmExcess, 0.);
              uncalibratedenergyHfEmTmp = max(uncalibratedenergyHfEmTmp - uncalibratedenergyHfEmExcess, 0.);
            }
            energyHfEm = energyHfEmTmp;
            uncalibratedenergyHfEm = uncalibratedenergyHfEmTmp;
            energyHfHad = energyHfHadTmp;
            continue;
          }
          break;
        }  // loop over hfemsattelites ends
      }    // if HFHAD is excessive or not
 
      //
      // Loop over all tracks associated to this HFHAD cluster *again* in order to produce charged hadrons
      //
      for (auto const& trk : sortedTracksActive) {
        unsigned iTrack = trk.second;
 
        // Sanity check
        reco::TrackRef trackRef = elements[iTrack].trackRef();
        assert(!trackRef.isNull());
 
        //
        // Reconstructing charged hadrons
        //
        unsigned tmpi = reconstructTrack(elements[iTrack]);
        active[iTrack] = false;
        (*pfCandidates_)[tmpi].addElementInBlock(blockref, iHfHad);
        auto myHfEms = associatedHfEms.equal_range(iTrack);
        for (auto ii = myHfEms.first; ii != myHfEms.second; ++ii) {
          unsigned iHfEm = ii->second.second;
          if (active[iHfEm])
            continue;
          (*pfCandidates_)[tmpi].addElementInBlock(blockref, iHfEm);
        }
        double frac = 0.;
        if (totalChargedMomentum)
          frac = trackRef->p() / totalChargedMomentum;
        (*pfCandidates_)[tmpi].setEcalEnergy(uncalibratedenergyHfEm * frac, energyHfEm * frac);
        (*pfCandidates_)[tmpi].setHcalEnergy(uncalibratedenergyHfHad * frac, energyHfHad * frac);
 
      }  // sortedTracks loop ends
 
    }  // iHfHad element loop ends
 
    //
    // Loop over remaining active HfEm clusters
    //
    for (unsigned iHfEm = 0; iHfEm < elements.size(); iHfEm++) {
      PFBlockElement::Type type = elements[iHfEm].type();
      if (type == PFBlockElement::HFEM && active[iHfEm]) {
        reco::PFClusterRef eclusterRef = elements[iHfEm].clusterRef();
        double energyHF = 0.;
        double uncalibratedenergyHF = 0.;
        unsigned tmpi = 0;
        // do EM-only calibration here
        energyHF = eclusterRef->energy();
        uncalibratedenergyHF = energyHF;
        if (thepfEnergyCalibrationHF_.getcalibHF_use()) {
          energyHF = thepfEnergyCalibrationHF_.energyEm(
              uncalibratedenergyHF, eclusterRef->positionREP().Eta(), eclusterRef->positionREP().Phi());
        }
        tmpi = reconstructCluster(*eclusterRef, energyHF);
        (*pfCandidates_)[tmpi].setEcalEnergy(uncalibratedenergyHF, energyHF);
        (*pfCandidates_)[tmpi].setHcalEnergy(0., 0.);
        (*pfCandidates_)[tmpi].addElementInBlock(blockref, iHfEm);
        active[iHfEm] = false;
        LogTrace("PFAlgo|createCandidatesHF") << "HF EM alone from blocks with tracks! " << energyHF;
      }
    }  // remaining active HfEm cluster loop ends
 
  }  // if-statement for blocks including tracks ends here
  //
  // -----------------------------------------------
  // From here, traditional PF HF candidate creation
  // -----------------------------------------------
  //
  else if (elements.size() == 1) {
    //Auguste: HAD-only calibration here
    reco::PFClusterRef clusterRef = elements[0].clusterRef();
    double energyHF = 0.;
    double uncalibratedenergyHF = 0.;
    unsigned tmpi = 0;
    switch (clusterRef->layer()) {
      case PFLayer::HF_EM:
        // do EM-only calibration here
        energyHF = clusterRef->energy();
        uncalibratedenergyHF = energyHF;
        if (thepfEnergyCalibrationHF_.getcalibHF_use()) {
          energyHF = thepfEnergyCalibrationHF_.energyEm(
              uncalibratedenergyHF, clusterRef->positionREP().Eta(), clusterRef->positionREP().Phi());
        }
        tmpi = reconstructCluster(*clusterRef, energyHF);
        (*pfCandidates_)[tmpi].setEcalEnergy(uncalibratedenergyHF, energyHF);
        (*pfCandidates_)[tmpi].setHcalEnergy(0., 0.);
        (*pfCandidates_)[tmpi].setHoEnergy(0., 0.);
        (*pfCandidates_)[tmpi].setPs1Energy(0.);
        (*pfCandidates_)[tmpi].setPs2Energy(0.);
        (*pfCandidates_)[tmpi].addElementInBlock(blockref, inds.hfEmIs[0]);
        LogTrace("PFAlgo|createCandidatesHF") << "HF EM alone ! " << energyHF;
        break;
      case PFLayer::HF_HAD:
        // do HAD-only calibration here
        energyHF = clusterRef->energy();
        uncalibratedenergyHF = energyHF;
        if (thepfEnergyCalibrationHF_.getcalibHF_use()) {
          energyHF = thepfEnergyCalibrationHF_.energyHad(
              uncalibratedenergyHF, clusterRef->positionREP().Eta(), clusterRef->positionREP().Phi());
        }
        tmpi = reconstructCluster(*clusterRef, energyHF);
        (*pfCandidates_)[tmpi].setHcalEnergy(uncalibratedenergyHF, energyHF);
        (*pfCandidates_)[tmpi].setEcalEnergy(0., 0.);
        (*pfCandidates_)[tmpi].setHoEnergy(0., 0.);
        (*pfCandidates_)[tmpi].setPs1Energy(0.);
        (*pfCandidates_)[tmpi].setPs2Energy(0.);
        (*pfCandidates_)[tmpi].addElementInBlock(blockref, inds.hfHadIs[0]);
        LogTrace("PFAlgo|createCandidatesHF") << "HF Had alone ! " << energyHF;
        break;
      default:
        assert(0);
    }
  } else if (elements.size() == 2) {
    //Auguste: EM + HAD calibration here
    reco::PFClusterRef c0 = elements[0].clusterRef();
    reco::PFClusterRef c1 = elements[1].clusterRef();
    // 2 HF elements. Must be in each layer.
    reco::PFClusterRef cem = (c0->layer() == PFLayer::HF_EM ? c0 : c1);
    reco::PFClusterRef chad = (c1->layer() == PFLayer::HF_HAD ? c1 : c0);
 
    if (cem->layer() != PFLayer::HF_EM || chad->layer() != PFLayer::HF_HAD) {
      edm::LogError("PFAlgo::createCandidatesHF") << "Error: 2 elements, but not 1 HFEM and 1 HFHAD";
      edm::LogError("PFAlgo::createCandidatesHF") << block;
      assert(0);
      //    assert( c1->layer()== PFLayer::HF_EM &&
      //        c0->layer()== PFLayer::HF_HAD );
    }
    // do EM+HAD calibration here
    double energyHfEm = cem->energy();
    double energyHfHad = chad->energy();
    double uncalibratedenergyHfEm = energyHfEm;
    double uncalibratedenergyHfHad = energyHfHad;
    if (thepfEnergyCalibrationHF_.getcalibHF_use()) {
      energyHfEm = thepfEnergyCalibrationHF_.energyEmHad(
          uncalibratedenergyHfEm, 0.0, c0->positionREP().Eta(), c0->positionREP().Phi());
      energyHfHad = thepfEnergyCalibrationHF_.energyEmHad(
          0.0, uncalibratedenergyHfHad, c1->positionREP().Eta(), c1->positionREP().Phi());
    }
    auto& cand = (*pfCandidates_)[reconstructCluster(*chad, energyHfEm + energyHfHad)];
    cand.setEcalEnergy(uncalibratedenergyHfEm, energyHfEm);
    cand.setHcalEnergy(uncalibratedenergyHfHad, energyHfHad);
    cand.setHoEnergy(0., 0.);
    cand.setPs1Energy(0.);
    cand.setPs2Energy(0.);
    cand.addElementInBlock(blockref, inds.hfEmIs[0]);
    cand.addElementInBlock(blockref, inds.hfHadIs[0]);
    LogTrace("PFAlgo|createCandidatesHF") << "HF EM+HAD found ! " << energyHfEm << " " << energyHfHad;
  } else {
    // Unusual blocks including HF elements, but do not fit any of the above categories
    edm::LogWarning("PFAlgo::createCandidatesHF")
        << "Warning: HF, but n elem different from 1 or 2 or >=3 or !trackIs.empty()";
    edm::LogWarning("PFAlgo::createCandidatesHF") << block;
  }
  LogTrace("PFAlgo|createCandidateHF") << "end of function PFAlgo::createCandidateHF";
}
 
void PFAlgo::createCandidatesHCAL(const reco::PFBlock& block,
                                  reco::PFBlock::LinkData& linkData,
                                  const edm::OwnVector<reco::PFBlockElement>& elements,
                                  std::vector<bool>& active,
                                  const reco::PFBlockRef& blockref,
                                  ElementIndices& inds,
                                  std::vector<bool>& deadArea) {
  LogTrace("PFAlgo|createCandidatesHCAL")
      << "start of function PFAlgo::createCandidatesHCAL, inds.hcalIs.size()=" << inds.hcalIs.size();
 
  // --------------- loop hcal ------------------
 
  for (unsigned iHcal : inds.hcalIs) {
    PFBlockElement::Type type = elements[iHcal].type();
 
    assert(type == PFBlockElement::HCAL);
 
    LogTrace("PFAlgo|createCandidatesHCAL") << "elements[" << iHcal << "]=" << elements[iHcal];
 
    // associated tracks
    std::multimap<double, unsigned> sortedTracks;
    block.associatedElements(iHcal, linkData, sortedTracks, reco::PFBlockElement::TRACK, reco::PFBlock::LINKTEST_ALL);
 
    std::multimap<unsigned, std::pair<double, unsigned>> associatedEcals;
 
    std::map<unsigned, std::pair<double, double>> associatedPSs;
 
    std::multimap<double, std::pair<unsigned, bool>> associatedTracks;
 
    // A temporary maps for ECAL satellite clusters
    std::multimap<double, std::tuple<unsigned, ::math::XYZVector, double>>
        ecalSatellites;  // last element (double) : correction under the egamma hypothesis
    std::tuple<unsigned, ::math::XYZVector, double> fakeSatellite(iHcal, ::math::XYZVector(0., 0., 0.), 1.);
    ecalSatellites.emplace(-1., fakeSatellite);
 
    std::multimap<unsigned, std::pair<double, unsigned>> associatedHOs;
 
    PFClusterRef hclusterref = elements[iHcal].clusterRef();
    assert(!hclusterref.isNull());
 
    //if there is no track attached to that HCAL, then do not
    //reconstruct an HCAL alone, check if it can be recovered
    //first
 
    // if no associated tracks, create a neutral hadron
    //if(sortedTracks.empty() ) {
 
    if (sortedTracks.empty()) {
      LogTrace("PFAlgo|createCandidatesHCAL") << "\tno associated tracks, keep for later";
      continue;
    }
 
    // Lock the HCAL cluster
    active[iHcal] = false;
 
    // in the following, tracks are associated to this hcal cluster.
    // will look for an excess of energy in the calorimeters w/r to
    // the charged energy, and turn this excess into a neutral hadron or
    // a photon.
 
    LogTrace("PFAlgo|createCandidatesHCAL") << sortedTracks.size() << " associated tracks:";
 
    double totalChargedMomentum = 0;
    double sumpError2 = 0.;
    double totalHO = 0.;
    double totalEcal = 0.;
    double totalEcalEGMCalib = 0.;
    double totalHcal = hclusterref->energy();
    vector<double> hcalP;
    vector<double> hcalDP;
    vector<unsigned> tkIs;
    double maxDPovP = -9999.;
 
    //Keep track of how much energy is assigned to calorimeter-vs-track energy/momentum excess
    vector<unsigned> chargedHadronsIndices;
    vector<unsigned> chargedHadronsInBlock;
    double mergedNeutralHadronEnergy = 0;
    double mergedPhotonEnergy = 0;
    double muonHCALEnergy = 0.;
    double muonECALEnergy = 0.;
    double muonHCALError = 0.;
    double muonECALError = 0.;
    unsigned nMuons = 0;
 
    ::math::XYZVector photonAtECAL(0., 0., 0.);
    std::vector<std::tuple<unsigned, ::math::XYZVector, double>>
        ecalClusters;  // last element (double) : correction under the egamma hypothesis
    double sumEcalClusters = 0;
    ::math::XYZVector hadronDirection(
        hclusterref->position().X(), hclusterref->position().Y(), hclusterref->position().Z());
    hadronDirection = hadronDirection.Unit();
    ::math::XYZVector hadronAtECAL = totalHcal * hadronDirection;
 
    // Loop over all tracks associated to this HCAL cluster
    for (auto const& trk : sortedTracks) {
      unsigned iTrack = trk.second;
 
      // Check the track has not already been used (e.g., in electrons, conversions...)
      if (!active[iTrack])
        continue;
      // Sanity check 1
      PFBlockElement::Type type = elements[iTrack].type();
      assert(type == reco::PFBlockElement::TRACK);
      // Sanity check 2
      reco::TrackRef trackRef = elements[iTrack].trackRef();
      assert(!trackRef.isNull());
 
      // The direction at ECAL entrance
      const ::math::XYZPointF& chargedPosition =
          dynamic_cast<const reco::PFBlockElementTrack*>(&elements[iTrack])->positionAtECALEntrance();
      ::math::XYZVector chargedDirection(chargedPosition.X(), chargedPosition.Y(), chargedPosition.Z());
      chargedDirection = chargedDirection.Unit();
 
      // look for ECAL elements associated to iTrack (associated to iHcal)
      std::multimap<double, unsigned> sortedEcals;
      block.associatedElements(iTrack, linkData, sortedEcals, reco::PFBlockElement::ECAL, reco::PFBlock::LINKTEST_ALL);
 
      LogTrace("PFAlgo|createCandidatesHCAL") << "number of Ecal elements linked to this track: " << sortedEcals.size();
 
      // look for HO elements associated to iTrack (associated to iHcal)
      std::multimap<double, unsigned> sortedHOs;
      if (useHO_) {
        block.associatedElements(iTrack, linkData, sortedHOs, reco::PFBlockElement::HO, reco::PFBlock::LINKTEST_ALL);
      }
      LogTrace("PFAlgo|createCandidatesHCAL")
          << "PFAlgo : number of HO elements linked to this track: " << sortedHOs.size();
 
      // Create a PF Candidate right away if the track is a tight muon
      reco::MuonRef muonRef = elements[iTrack].muonRef();
 
      bool thisIsAMuon = PFMuonAlgo::isMuon(elements[iTrack]);
      bool thisIsAnIsolatedMuon = PFMuonAlgo::isIsolatedMuon(elements[iTrack]);
      bool thisIsALooseMuon = false;
 
      if (!thisIsAMuon) {
        thisIsALooseMuon = PFMuonAlgo::isLooseMuon(elements[iTrack]);
      }
 
      if (thisIsAMuon) {
        LogTrace("PFAlgo|createCandidatesHCAL") << "This track is identified as a muon - remove it from the stack";
        LogTrace("PFAlgo|createCandidatesHCAL") << elements[iTrack];
 
        // Create a muon.
 
        unsigned tmpi = reconstructTrack(elements[iTrack]);
 
        (*pfCandidates_)[tmpi].addElementInBlock(blockref, iTrack);
        (*pfCandidates_)[tmpi].addElementInBlock(blockref, iHcal);
        double muonHcal = std::min(muonHCAL_[0] + muonHCAL_[1], totalHcal);
 
        // if muon is isolated and muon momentum exceeds the calo energy, absorb the calo energy
        // rationale : there has been a EM showering by the muon in the calorimeter - or the coil -
        // and we don't want to double count the energy
        bool letMuonEatCaloEnergy = false;
 
        if (thisIsAnIsolatedMuon) {
          // The factor 1.3 is the e/pi factor in HCAL...
          double totalCaloEnergy = totalHcal / 1.30;
          unsigned iEcal = 0;
          if (!sortedEcals.empty()) {
            iEcal = sortedEcals.begin()->second;
            PFClusterRef eclusterref = elements[iEcal].clusterRef();
            totalCaloEnergy += eclusterref->energy();
          }
 
          if (useHO_) {
            // The factor 1.3 is assumed to be the e/pi factor in HO, too.
            unsigned iHO = 0;
            if (!sortedHOs.empty()) {
              iHO = sortedHOs.begin()->second;
              PFClusterRef eclusterref = elements[iHO].clusterRef();
              totalCaloEnergy += eclusterref->energy() / 1.30;
            }
          }
 
          if ((pfCandidates_->back()).p() > totalCaloEnergy)
            letMuonEatCaloEnergy = true;
        }
 
        if (letMuonEatCaloEnergy)
          muonHcal = totalHcal;
        double muonEcal = 0.;
        unsigned iEcal = 0;
        if (!sortedEcals.empty()) {
          iEcal = sortedEcals.begin()->second;
          PFClusterRef eclusterref = elements[iEcal].clusterRef();
          (*pfCandidates_)[tmpi].addElementInBlock(blockref, iEcal);
          muonEcal = std::min(muonECAL_[0] + muonECAL_[1], eclusterref->energy());
          if (letMuonEatCaloEnergy)
            muonEcal = eclusterref->energy();
          // If the muon expected energy accounts for the whole ecal cluster energy, lock the ecal cluster
          if (eclusterref->energy() - muonEcal < 0.2)
            active[iEcal] = false;
          (*pfCandidates_)[tmpi].setEcalEnergy(eclusterref->energy(), muonEcal);
        }
        unsigned iHO = 0;
        double muonHO = 0.;
        if (useHO_) {
          if (!sortedHOs.empty()) {
            iHO = sortedHOs.begin()->second;
            PFClusterRef hoclusterref = elements[iHO].clusterRef();
            (*pfCandidates_)[tmpi].addElementInBlock(blockref, iHO);
            muonHO = std::min(muonHO_[0] + muonHO_[1], hoclusterref->energy());
            if (letMuonEatCaloEnergy)
              muonHO = hoclusterref->energy();
            // If the muon expected energy accounts for the whole HO cluster energy, lock the HO cluster
            if (hoclusterref->energy() - muonHO < 0.2)
              active[iHO] = false;
            (*pfCandidates_)[tmpi].setHcalEnergy(totalHcal, muonHcal);
            (*pfCandidates_)[tmpi].setHoEnergy(hoclusterref->energy(), muonHO);
          }
        } else {
          (*pfCandidates_)[tmpi].setHcalEnergy(totalHcal, muonHcal);
        }
        setHcalDepthInfo((*pfCandidates_)[tmpi], *hclusterref);
 
        if (letMuonEatCaloEnergy) {
          muonHCALEnergy += totalHcal;
          if (useHO_)
            muonHCALEnergy += muonHO;
          muonHCALError += 0.;
          muonECALEnergy += muonEcal;
          muonECALError += 0.;
          photonAtECAL -= muonEcal * chargedDirection;
          hadronAtECAL -= totalHcal * chargedDirection;
          if (!sortedEcals.empty())
            active[iEcal] = false;
          active[iHcal] = false;
          if (useHO_ && !sortedHOs.empty())
            active[iHO] = false;
        } else {
          // Estimate of the energy deposit & resolution in the calorimeters
          muonHCALEnergy += muonHCAL_[0];
          muonHCALError += muonHCAL_[1] * muonHCAL_[1];
          if (muonHO > 0.) {
            muonHCALEnergy += muonHO_[0];
            muonHCALError += muonHO_[1] * muonHO_[1];
          }
          muonECALEnergy += muonECAL_[0];
          muonECALError += muonECAL_[1] * muonECAL_[1];
          // ... as well as the equivalent "momentum" at ECAL entrance
          photonAtECAL -= muonECAL_[0] * chargedDirection;
          hadronAtECAL -= muonHCAL_[0] * chargedDirection;
        }
 
        // Remove it from the stack
        active[iTrack] = false;
        // Go to next track
        continue;
      }
 
      //
 
      LogTrace("PFAlgo|createCandidatesHCAL") << "elements[iTrack=" << iTrack << "]=" << elements[iTrack];
 
      // introduce tracking errors
      double trackMomentum = trackRef->p();
      totalChargedMomentum += trackMomentum;
 
      // If the track is not a tight muon, but still resembles a muon
      // keep it for later for blocks with too large a charged energy
      if (thisIsALooseMuon && !thisIsAMuon)
        nMuons += 1;
 
      // ... and keep anyway the pt error for possible fake rejection
      // ... blow up errors of 5th and 4th iteration, to reject those
      // ... tracks first (in case it's needed)
      double dpt = trackRef->ptError();
      double blowError = PFTrackAlgoTools::errorScale(trackRef->algo(), factors45_);
      // except if it is from an interaction
      bool isPrimaryOrSecondary = isFromSecInt(elements[iTrack], "all");
 
      if (isPrimaryOrSecondary)
        blowError = 1.;
 
      std::pair<unsigned, bool> tkmuon(iTrack, thisIsALooseMuon);
      associatedTracks.emplace(-dpt * blowError, tkmuon);
 
      // Also keep the total track momentum error for comparison with the calo energy
      double dp = trackRef->qoverpError() * trackMomentum * trackMomentum;
      sumpError2 += dp * dp;
 
      bool connectedToEcal = false;  // Will become true if there is at least one ECAL cluster connected
      if (!sortedEcals.empty()) {    // start case: at least one ecal element associated to iTrack
 
        // Loop over all connected ECAL clusters
        for (auto const& ecal : sortedEcals) {
          unsigned iEcal = ecal.second;
          double dist = ecal.first;
 
          // Ignore ECAL cluters already used
          if (!active[iEcal]) {
            LogTrace("PFAlgo|createCandidatesHCAL") << "cluster locked";
            continue;
          }
 
          // Sanity checks
          PFBlockElement::Type type = elements[iEcal].type();
          assert(type == PFBlockElement::ECAL);
          PFClusterRef eclusterref = elements[iEcal].clusterRef();
          assert(!eclusterref.isNull());
 
          // Check if this ECAL is not closer to another track - ignore it in that case
          std::multimap<double, unsigned> sortedTracksEcal;
          block.associatedElements(
              iEcal, linkData, sortedTracksEcal, reco::PFBlockElement::TRACK, reco::PFBlock::LINKTEST_ALL);
          unsigned jTrack = sortedTracksEcal.begin()->second;
          if (jTrack != iTrack)
            continue;
 
          double distEcal = block.dist(jTrack, iEcal, linkData, reco::PFBlock::LINKTEST_ALL);
 
          float ecalEnergyCalibrated = eclusterref->correctedEnergy();  // calibrated based on the egamma hypothesis
          float ecalEnergy = eclusterref->energy();
          ::math::XYZVector photonDirection(
              eclusterref->position().X(), eclusterref->position().Y(), eclusterref->position().Z());
          photonDirection = photonDirection.Unit();
 
          if (!connectedToEcal) {  // This is the closest ECAL cluster - will add its energy later
 
            LogTrace("PFAlgo|createCandidatesHCAL") << "closest: " << elements[iEcal];
 
            connectedToEcal = true;
            // PJ 1st-April-09 : To be done somewhere !!! (Had to comment it, but it is needed)
            // currentChargedHadron.addElementInBlock( blockref, iEcal );
 
            // KH: we don't know if this satellite is due to egamma or hadron shower. use raw energy for PF hadron calibration._ store also calibration constant.
            double ecalCalibFactor = (ecalEnergy > 1E-9) ? ecalEnergyCalibrated / ecalEnergy : 1.;
            std::tuple<unsigned, ::math::XYZVector, double> satellite(
                iEcal, ecalEnergy * photonDirection, ecalCalibFactor);
            ecalSatellites.emplace(-1., satellite);
 
          } else {  // Keep satellite clusters for later
 
            // KH: same as above.
            double ecalCalibFactor = (ecalEnergy > 1E-9) ? ecalEnergyCalibrated / ecalEnergy : 1.;
            std::tuple<unsigned, ::math::XYZVector, double> satellite(
                iEcal, ecalEnergy * photonDirection, ecalCalibFactor);
            ecalSatellites.emplace(dist, satellite);
          }
 
          std::pair<double, unsigned> associatedEcal(distEcal, iEcal);
          associatedEcals.emplace(iTrack, associatedEcal);
 
        }  // End loop ecal associated to iTrack
      }    // end case: at least one ecal element associated to iTrack
 
      if (useHO_ && !sortedHOs.empty()) {  // start case: at least one ho element associated to iTrack
 
        // Loop over all connected HO clusters
        for (auto const& ho : sortedHOs) {
          unsigned iHO = ho.second;
          double distHO = ho.first;
 
          // Ignore HO cluters already used
          if (!active[iHO]) {
            LogTrace("PFAlgo|createCandidatesHCAL") << "cluster locked";
            continue;
          }
 
          // Sanity checks
          PFBlockElement::Type type = elements[iHO].type();
          assert(type == PFBlockElement::HO);
          PFClusterRef hoclusterref = elements[iHO].clusterRef();
          assert(!hoclusterref.isNull());
 
          // Check if this HO is not closer to another track - ignore it in that case
          std::multimap<double, unsigned> sortedTracksHO;
          block.associatedElements(
              iHO, linkData, sortedTracksHO, reco::PFBlockElement::TRACK, reco::PFBlock::LINKTEST_ALL);
          unsigned jTrack = sortedTracksHO.begin()->second;
          if (jTrack != iTrack)
            continue;
 
          // double chi2HO = block.chi2(jTrack,iHO,linkData,
          //                              reco::PFBlock::LINKTEST_ALL);
          //double distHO = block.dist(jTrack,iHO,linkData,
          //               reco::PFBlock::LINKTEST_ALL);
 
          // Increment the total energy by the energy of this HO cluster
          totalHO += hoclusterref->energy();
          active[iHO] = false;
          // Keep track for later reference in the PFCandidate.
          std::pair<double, unsigned> associatedHO(distHO, iHO);
          associatedHOs.emplace(iTrack, associatedHO);
 
        }  // End loop ho associated to iTrack
      }    // end case: at least one ho element associated to iTrack
 
    }  // end loop on tracks associated to hcal element iHcal
 
    // Include totalHO in totalHCAL for the time being (it will be calibrated as HCAL energy)
    totalHcal += totalHO;
 
    // test compatibility between calo and tracker. //////////////
 
    double caloEnergy = 0.;
    double slopeEcal = 1.0;
    double calibEcal = 0.;
    double calibHcal = 0.;
    hadronDirection = hadronAtECAL.Unit();
 
    // Determine the expected calo resolution from the total charged momentum
    double caloResolution = neutralHadronEnergyResolution(totalChargedMomentum, hclusterref->positionREP().Eta());
    caloResolution *= totalChargedMomentum;
    // Account for muons
    caloResolution = std::sqrt(caloResolution * caloResolution + muonHCALError + muonECALError);
    totalEcal -= std::min(totalEcal, muonECALEnergy);
    totalEcalEGMCalib -= std::min(totalEcalEGMCalib, muonECALEnergy);
    totalHcal -= std::min(totalHcal, muonHCALEnergy);
    if (totalEcal < 1E-9)
      photonAtECAL = ::math::XYZVector(0., 0., 0.);
    if (totalHcal < 1E-9)
      hadronAtECAL = ::math::XYZVector(0., 0., 0.);
 
    // Loop over all ECAL satellites, starting for the closest to the various tracks
    // and adding other satellites until saturation of the total track momentum
    // Note : for code simplicity, the first element of the loop is the HCAL cluster
    // with 0 energy in the ECAL
    for (auto const& ecalSatellite : ecalSatellites) {
      // Add the energy of this ECAL cluster
      double previousCalibEcal = calibEcal;
      double previousCalibHcal = calibHcal;
      double previousCaloEnergy = caloEnergy;
      double previousSlopeEcal = slopeEcal;
      ::math::XYZVector previousHadronAtECAL = hadronAtECAL;
      //
      totalEcal +=
          sqrt(std::get<1>(ecalSatellite.second).Mag2());  // KH: raw ECAL energy for input to PF hadron calibration
      totalEcalEGMCalib += sqrt(std::get<1>(ecalSatellite.second).Mag2()) *
                           std::get<2>(ecalSatellite.second);  // KH: calibrated ECAL energy under the egamma hypothesis
      photonAtECAL += std::get<1>(ecalSatellite.second) *
                      std::get<2>(ecalSatellite.second);  // KH: calibrated ECAL energy under the egamma hypothesis
      calibEcal = std::max(0., totalEcal);                // KH: preparing for hadron calibration
      calibHcal = std::max(0., totalHcal);
      hadronAtECAL = calibHcal * hadronDirection;
      // Calibrate ECAL and HCAL energy under the hadron hypothesis.
      calibration_.energyEmHad(totalChargedMomentum,
                               calibEcal,
                               calibHcal,
                               hclusterref->positionREP().Eta(),
                               hclusterref->positionREP().Phi());
      caloEnergy = calibEcal + calibHcal;
      if (totalEcal > 0.)
        slopeEcal = calibEcal / totalEcal;
 
      hadronAtECAL = calibHcal * hadronDirection;
 
      // Continue looping until all closest clusters are exhausted and as long as
      // the calorimetric energy does not saturate the total momentum.
      if (ecalSatellite.first < 0. || caloEnergy - totalChargedMomentum <= 0.) {
        LogTrace("PFAlgo|createCandidatesHCAL")
            << "\t\t\tactive, adding " << std::get<1>(ecalSatellite.second) << " to ECAL energy, and locking";
        active[std::get<0>(ecalSatellite.second)] = false;
        double clusterEnergy =
            sqrt(std::get<1>(ecalSatellite.second).Mag2()) *
            std::get<2>(ecalSatellite.second);  // KH: ECAL energy calibrated under the egamma hypothesis
        if (clusterEnergy > 50) {               // KH: used to split energetic ecal clusters (E>50 GeV)
          ecalClusters.push_back(ecalSatellite.second);
          sumEcalClusters += clusterEnergy;
        }
        continue;
      }
 
      // Otherwise, do not consider the last cluster examined and exit.
      // active[is->second.first] = true;
      totalEcal -= sqrt(std::get<1>(ecalSatellite.second).Mag2());
      totalEcalEGMCalib -= sqrt(std::get<1>(ecalSatellite.second).Mag2()) * std::get<2>(ecalSatellite.second);
      photonAtECAL -= std::get<1>(ecalSatellite.second) * std::get<2>(ecalSatellite.second);
      calibEcal = previousCalibEcal;
      calibHcal = previousCalibHcal;
      hadronAtECAL = previousHadronAtECAL;
      slopeEcal = previousSlopeEcal;
      caloEnergy = previousCaloEnergy;
 
      break;
    }
 
    // Sanity check !
    assert(caloEnergy >= 0);
 
    // And now check for hadronic energy excess...
 
    //colin: resolution should be measured on the ecal+hcal case.
    // however, the result will be close.
    // double caloResolution = neutralHadronEnergyResolution( caloEnergy );
    // caloResolution *= caloEnergy;
    // PJ The resolution is on the expected charged calo energy !
    //double caloResolution = neutralHadronEnergyResolution( totalChargedMomentum, hclusterref->positionREP().Eta());
    //caloResolution *= totalChargedMomentum;
    // that of the charged particles linked to the cluster!
 
    if (totalChargedMomentum - caloEnergy > nSigmaTRACK_ * caloResolution) {
      // First consider loose muons
      if (nMuons > 0) {
        for (auto const& trk : associatedTracks) {
          // Only muons
          if (!trk.second.second)
            continue;
 
          const unsigned int iTrack = trk.second.first;
          // Only active tracks
          if (!active[iTrack])
            continue;
 
          const double trackMomentum = elements[trk.second.first].trackRef()->p();
 
          // look for ECAL elements associated to iTrack (associated to iHcal)
          std::multimap<double, unsigned> sortedEcals;
          block.associatedElements(
              iTrack, linkData, sortedEcals, reco::PFBlockElement::ECAL, reco::PFBlock::LINKTEST_ALL);
          std::multimap<double, unsigned> sortedHOs;
          block.associatedElements(iTrack, linkData, sortedHOs, reco::PFBlockElement::HO, reco::PFBlock::LINKTEST_ALL);
 
          //Here allow for loose muons!
          auto& muon = (*pfCandidates_)[reconstructTrack(elements[iTrack], true)];
 
          muon.addElementInBlock(blockref, iTrack);
          muon.addElementInBlock(blockref, iHcal);
          const double muonHcal = std::min(muonHCAL_[0] + muonHCAL_[1], totalHcal - totalHO);
          double muonHO = 0.;
          muon.setHcalEnergy(totalHcal, muonHcal);
          if (!sortedEcals.empty()) {
            const unsigned int iEcal = sortedEcals.begin()->second;
            PFClusterRef eclusterref = elements[iEcal].clusterRef();
            muon.addElementInBlock(blockref, iEcal);
            const double muonEcal = std::min(muonECAL_[0] + muonECAL_[1], eclusterref->energy());
            muon.setEcalEnergy(eclusterref->energy(), muonEcal);
          }
          if (useHO_ && !sortedHOs.empty()) {
            const unsigned int iHO = sortedHOs.begin()->second;
            PFClusterRef hoclusterref = elements[iHO].clusterRef();
            muon.addElementInBlock(blockref, iHO);
            muonHO = std::min(muonHO_[0] + muonHO_[1], hoclusterref->energy());
            muon.setHcalEnergy(max(totalHcal - totalHO, 0.0), muonHcal);
            muon.setHoEnergy(hoclusterref->energy(), muonHO);
          }
          setHcalDepthInfo(muon, *hclusterref);
          // Remove it from the block
          const ::math::XYZPointF& chargedPosition =
              dynamic_cast<const reco::PFBlockElementTrack*>(&elements[trk.second.first])->positionAtECALEntrance();
          ::math::XYZVector chargedDirection(chargedPosition.X(), chargedPosition.Y(), chargedPosition.Z());
          chargedDirection = chargedDirection.Unit();
          totalChargedMomentum -= trackMomentum;
          // Update the calo energies
          if (totalEcal > 0.)
            calibEcal -= std::min(calibEcal, muonECAL_[0] * calibEcal / totalEcal);
          if (totalHcal > 0.)
            calibHcal -= std::min(calibHcal, muonHCAL_[0] * calibHcal / totalHcal);
          totalEcal -= std::min(totalEcal, muonECAL_[0]);
          totalHcal -= std::min(totalHcal, muonHCAL_[0]);
          if (totalEcal > muonECAL_[0])
            photonAtECAL -= muonECAL_[0] * chargedDirection;
          if (totalHcal > muonHCAL_[0])
            hadronAtECAL -= muonHCAL_[0] * calibHcal / totalHcal * chargedDirection;
          caloEnergy = calibEcal + calibHcal;
          muonHCALEnergy += muonHCAL_[0];
          muonHCALError += muonHCAL_[1] * muonHCAL_[1];
          if (muonHO > 0.) {
            muonHCALEnergy += muonHO_[0];
            muonHCALError += muonHO_[1] * muonHO_[1];
            if (totalHcal > 0.) {
              calibHcal -= std::min(calibHcal, muonHO_[0] * calibHcal / totalHcal);
              totalHcal -= std::min(totalHcal, muonHO_[0]);
            }
          }
          muonECALEnergy += muonECAL_[0];
          muonECALError += muonECAL_[1] * muonECAL_[1];
          active[iTrack] = false;
          // Stop the loop whenever enough muons are removed
          //Commented out: Keep looking for muons since they often come in pairs -Matt
          //if ( totalChargedMomentum < caloEnergy ) break;
        }
        // New calo resolution.
        caloResolution = neutralHadronEnergyResolution(totalChargedMomentum, hclusterref->positionREP().Eta());
        caloResolution *= totalChargedMomentum;
        caloResolution = std::sqrt(caloResolution * caloResolution + muonHCALError + muonECALError);
      }
    }
 
#ifdef EDM_ML_DEBUG
    LogTrace("PFAlgo|createCandidatesHCAL") << "\tBefore Cleaning ";
    LogTrace("PFAlgo|createCandidatesHCAL") << "\tCompare Calo Energy to total charged momentum ";
    LogTrace("PFAlgo|createCandidatesHCAL") << "\t\tsum p    = " << totalChargedMomentum << " +- " << sqrt(sumpError2);
    LogTrace("PFAlgo|createCandidatesHCAL") << "\t\tsum ecal = " << totalEcal;
    LogTrace("PFAlgo|createCandidatesHCAL") << "\t\tsum hcal = " << totalHcal;
    LogTrace("PFAlgo|createCandidatesHCAL") << "\t\t => Calo Energy = " << caloEnergy << " +- " << caloResolution;
    LogTrace("PFAlgo|createCandidatesHCAL")
        << "\t\t => Calo Energy- total charged momentum = " << caloEnergy - totalChargedMomentum << " +- "
        << sqrt(sumpError2 + caloResolution * caloResolution);
#endif
 
    // Second consider bad tracks (if still needed after muon removal)
    unsigned corrTrack = 10000000;
    double corrFact = 1.;
 
    if (rejectTracks_Bad_ && totalChargedMomentum - caloEnergy > nSigmaTRACK_ * caloResolution) {
      for (auto const& trk : associatedTracks) {
        const unsigned iTrack = trk.second.first;
        // Only active tracks
        if (!active[iTrack])
          continue;
        const reco::TrackRef& trackref = elements[trk.second.first].trackRef();
 
        const double dptRel = fabs(trk.first) / trackref->pt() * 100;
        const bool isSecondary = isFromSecInt(elements[iTrack], "secondary");
        const bool isPrimary = isFromSecInt(elements[iTrack], "primary");
 
        if (isSecondary && dptRel < dptRel_DispVtx_)
          continue;
        // Consider only bad tracks
        if (fabs(trk.first) < ptError_)
          break;
        // What would become the block charged momentum if this track were removed
        const double wouldBeTotalChargedMomentum = totalChargedMomentum - trackref->p();
        // Reject worst tracks, as long as the total charged momentum
        // is larger than the calo energy
 
        if (wouldBeTotalChargedMomentum > caloEnergy) {
          if (isSecondary) {
            LogTrace("PFAlgo|createCandidatesHCAL")
                << "In bad track rejection step dptRel = " << dptRel << " dptRel_DispVtx_ = " << dptRel_DispVtx_;
            LogTrace("PFAlgo|createCandidatesHCAL")
                << "The calo energy would be still smaller even without this track but it is attached to a NI";
          }
 
          if (isPrimary || (isSecondary && dptRel < dptRel_DispVtx_))
            continue;
          active[iTrack] = false;
          totalChargedMomentum = wouldBeTotalChargedMomentum;
          LogTrace("PFAlgo|createCandidatesHCAL")
              << "\tElement  " << elements[iTrack] << " rejected (dpt = " << -trk.first
              << " GeV/c, algo = " << trackref->algo() << ")";
          // Just rescale the nth worst track momentum to equalize the calo energy
        } else {
          if (isPrimary)
            break;
          corrTrack = iTrack;
          corrFact = (caloEnergy - wouldBeTotalChargedMomentum) / elements[trk.second.first].trackRef()->p();
          if (trackref->p() * corrFact < 0.05) {
            corrFact = 0.;
            active[iTrack] = false;
          }
          totalChargedMomentum -= trackref->p() * (1. - corrFact);
          LogTrace("PFAlgo|createCandidatesHCAL")
              << "\tElement  " << elements[iTrack] << " (dpt = " << -trk.first << " GeV/c, algo = " << trackref->algo()
              << ") rescaled by " << corrFact << " Now the total charged momentum is " << totalChargedMomentum;
          break;
        }
      }
    }
 
    // New determination of the calo and track resolution avec track deletion/rescaling.
    caloResolution = neutralHadronEnergyResolution(totalChargedMomentum, hclusterref->positionREP().Eta());
    caloResolution *= totalChargedMomentum;
    caloResolution = std::sqrt(caloResolution * caloResolution + muonHCALError + muonECALError);
 
    // Check if the charged momentum is still very inconsistent with the calo measurement.
    // In this case, just drop all tracks from 4th and 5th iteration linked to this block
 
    if (rejectTracks_Step45_ && sortedTracks.size() > 1 &&
        totalChargedMomentum - caloEnergy > nSigmaTRACK_ * caloResolution) {
      for (auto const& trk : associatedTracks) {
        unsigned iTrack = trk.second.first;
        reco::TrackRef trackref = elements[iTrack].trackRef();
        if (!active[iTrack])
          continue;
 
        double dptRel = fabs(trk.first) / trackref->pt() * 100;
        bool isPrimaryOrSecondary = isFromSecInt(elements[iTrack], "all");
 
        if (isPrimaryOrSecondary && dptRel < dptRel_DispVtx_)
          continue;
 
        if (PFTrackAlgoTools::step5(trackref->algo())) {
          active[iTrack] = false;
          totalChargedMomentum -= trackref->p();
 
          LogTrace("PFAlgo|createCandidatesHCAL")
              << "\tElement  " << elements[iTrack] << " rejected (dpt = " << -trk.first
              << " GeV/c, algo = " << trackref->algo() << ")";
        }
      }
    }
 
    // New determination of the calo and track resolution avec track deletion/rescaling.
    caloResolution = neutralHadronEnergyResolution(totalChargedMomentum, hclusterref->positionREP().Eta());
    caloResolution *= totalChargedMomentum;
    caloResolution = std::sqrt(caloResolution * caloResolution + muonHCALError + muonECALError);
 
    // Make PF candidates with the remaining tracks in the block
    sumpError2 = 0.;
    for (auto const& trk : associatedTracks) {
      unsigned iTrack = trk.second.first;
      if (!active[iTrack])
        continue;
      reco::TrackRef trackRef = elements[iTrack].trackRef();
      double trackMomentum = trackRef->p();
      double dp = trackRef->qoverpError() * trackMomentum * trackMomentum;
      unsigned tmpi = reconstructTrack(elements[iTrack]);
 
      (*pfCandidates_)[tmpi].addElementInBlock(blockref, iTrack);
      (*pfCandidates_)[tmpi].addElementInBlock(blockref, iHcal);
      setHcalDepthInfo((*pfCandidates_)[tmpi], *hclusterref);
      auto myEcals = associatedEcals.equal_range(iTrack);
      for (auto ii = myEcals.first; ii != myEcals.second; ++ii) {
        unsigned iEcal = ii->second.second;
        if (active[iEcal])
          continue;
        (*pfCandidates_)[tmpi].addElementInBlock(blockref, iEcal);
      }
 
      if (useHO_) {
        auto myHOs = associatedHOs.equal_range(iTrack);
        for (auto ii = myHOs.first; ii != myHOs.second; ++ii) {
          unsigned iHO = ii->second.second;
          if (active[iHO])
            continue;
          (*pfCandidates_)[tmpi].addElementInBlock(blockref, iHO);
        }
      }
 
      if (iTrack == corrTrack) {
        if (corrFact < 0.)
          corrFact = 0.;  // protect against negative scaling
        (*pfCandidates_)[tmpi].rescaleMomentum(corrFact);
        trackMomentum *= corrFact;
      }
      chargedHadronsIndices.push_back(tmpi);
      chargedHadronsInBlock.push_back(iTrack);
      active[iTrack] = false;
      hcalP.push_back(trackMomentum);
      hcalDP.push_back(dp);
      if (dp / trackMomentum > maxDPovP)
        maxDPovP = dp / trackMomentum;
      sumpError2 += dp * dp;
    }
 
    // The total uncertainty of the difference Calo-Track
    double totalError = sqrt(sumpError2 + caloResolution * caloResolution);
 
#ifdef EDM_ML_DEBUG
    LogTrace("PFAlgo|createCandidatesHCAL")
        << "\tCompare Calo Energy to total charged momentum " << endl
        << "\t\tsum p    = " << totalChargedMomentum << " +- " << sqrt(sumpError2) << endl
        << "\t\tsum ecal = " << totalEcal << endl
        << "\t\tsum hcal = " << totalHcal << endl
        << "\t\t => Calo Energy = " << caloEnergy << " +- " << caloResolution << endl
        << "\t\t => Calo Energy- total charged momentum = " << caloEnergy - totalChargedMomentum << " +- "
        << totalError;
#endif
 
    /* */
 
    double nsigma = nSigmaHCAL(totalChargedMomentum, hclusterref->positionREP().Eta());
    //double nsigma = nSigmaHCAL(caloEnergy,hclusterref->positionREP().Eta());
    if (abs(totalChargedMomentum - caloEnergy) < nsigma * totalError) {
      // deposited caloEnergy compatible with total charged momentum
      // if tracking errors are large take weighted average
 
#ifdef EDM_ML_DEBUG
      LogTrace("PFAlgo|createCandidatesHCAL")
          << "\t\tcase 1: COMPATIBLE "
          << "|Calo Energy- total charged momentum| = " << abs(caloEnergy - totalChargedMomentum) << " < " << nsigma
          << " x " << totalError;
      if (maxDPovP < 0.1)
        LogTrace("PFAlgo|createCandidatesHCAL") << "\t\t\tmax DP/P = " << maxDPovP << " less than 0.1: do nothing ";
      else
        LogTrace("PFAlgo|createCandidatesHCAL")
            << "\t\t\tmax DP/P = " << maxDPovP << " >  0.1: take weighted averages ";
#endif
 
      // if max DP/P < 10%  do nothing
      if (maxDPovP > 0.1) {
        // for each track associated to hcal
        //      int nrows = tkIs.size();
        int nrows = chargedHadronsIndices.size();
        TMatrixTSym<double> a(nrows);
        TVectorD b(nrows);
        TVectorD check(nrows);
        double sigma2E = caloResolution * caloResolution;
        for (int i = 0; i < nrows; i++) {
          double sigma2i = hcalDP[i] * hcalDP[i];
          LogTrace("PFAlgo|createCandidatesHCAL")
              << "\t\t\ttrack associated to hcal " << i << " P = " << hcalP[i] << " +- " << hcalDP[i];
          a(i, i) = 1. / sigma2i + 1. / sigma2E;
          b(i) = hcalP[i] / sigma2i + caloEnergy / sigma2E;
          for (int j = 0; j < nrows; j++) {
            if (i == j)
              continue;
            a(i, j) = 1. / sigma2E;
          }  // end loop on j
        }    // end loop on i
 
        // solve ax = b
        TDecompChol decomp(a);
        bool ok = false;
        TVectorD x = decomp.Solve(b, ok);
        // for each track create a PFCandidate track
        // with a momentum rescaled to weighted average
        if (ok) {
          for (int i = 0; i < nrows; i++) {
            //      unsigned iTrack = trackInfos[i].index;
            unsigned ich = chargedHadronsIndices[i];
            double rescaleFactor = x(i) / hcalP[i];
            if (rescaleFactor < 0.)
              rescaleFactor = 0.;  // protect against negative scaling
            (*pfCandidates_)[ich].rescaleMomentum(rescaleFactor);
 
            LogTrace("PFAlgo|createCandidatesHCAL")
                << "\t\t\told p " << hcalP[i] << " new p " << x(i) << " rescale " << rescaleFactor;
          }
        } else {
          edm::LogError("PFAlgo::createCandidatesHCAL") << "TDecompChol.Solve returned ok=false";
          assert(0);
        }
      }
    }
 
    else if (caloEnergy > totalChargedMomentum) {
      //case 2: caloEnergy > totalChargedMomentum + nsigma*totalError
      //there is an excess of energy in the calos
      //create a neutral hadron or a photon
 
      double eNeutralHadron = caloEnergy - totalChargedMomentum;
      double ePhoton = (caloEnergy - totalChargedMomentum) /
                       slopeEcal;  // KH: this slopeEcal is computed based on ECAL energy under the hadron hypothesis,
                                   // thought we are creating photons.
      // This is a fuzzy case, but it should be better than corrected twice under both egamma and hadron hypotheses.
 
#ifdef EDM_ML_DEBUG
      if (!sortedTracks.empty()) {
        LogTrace("PFAlgo|createCandidatesHCAL") << "\t\tcase 2: NEUTRAL DETECTION " << caloEnergy << " > " << nsigma
                                                << "x" << totalError << " + " << totalChargedMomentum;
        LogTrace("PFAlgo|createCandidatesHCAL") << "\t\tneutral activity detected: " << endl
                                                << "\t\t\t           photon = " << ePhoton << endl
                                                << "\t\t\tor neutral hadron = " << eNeutralHadron;
 
        LogTrace("PFAlgo|createCandidatesHCAL") << "\t\tphoton or hadron ?";
      }
 
      if (sortedTracks.empty())
        LogTrace("PFAlgo|createCandidatesHCAL") << "\t\tno track -> hadron ";
      else
        LogTrace("PFAlgo|createCandidatesHCAL")
            << "\t\t" << sortedTracks.size() << " tracks -> check if the excess is photonic or hadronic";
#endif
 
      double ratioMax = 0.;
      reco::PFClusterRef maxEcalRef;
      unsigned maxiEcal = 9999;
 
      // for each track associated to hcal: iterator IE ie :
 
      LogTrace("PFAlgo|createCandidatesHCAL") << "loop over sortedTracks.size()=" << sortedTracks.size();
      for (auto const& trk : sortedTracks) {
        unsigned iTrack = trk.second;
 
        PFBlockElement::Type type = elements[iTrack].type();
        assert(type == reco::PFBlockElement::TRACK);
 
        reco::TrackRef trackRef = elements[iTrack].trackRef();
        assert(!trackRef.isNull());
 
        auto iae = associatedEcals.find(iTrack);
 
        if (iae == associatedEcals.end())
          continue;
 
        // double distECAL = iae->second.first;
        unsigned iEcal = iae->second.second;
 
        PFBlockElement::Type typeEcal = elements[iEcal].type();
        assert(typeEcal == reco::PFBlockElement::ECAL);
 
        reco::PFClusterRef clusterRef = elements[iEcal].clusterRef();
        assert(!clusterRef.isNull());
 
        double pTrack = trackRef->p();
        double eECAL = clusterRef->energy();
        double eECALOverpTrack = eECAL / pTrack;
 
        if (eECALOverpTrack > ratioMax) {
          ratioMax = eECALOverpTrack;
          maxEcalRef = clusterRef;
          maxiEcal = iEcal;
        }
 
      }  // end loop on tracks associated to hcal: iterator IE ie
 
      std::vector<reco::PFClusterRef> pivotalClusterRef;
      std::vector<unsigned> iPivotal;
      std::vector<double> particleEnergy, ecalEnergy, hcalEnergy, rawecalEnergy, rawhcalEnergy;
      std::vector<::math::XYZVector> particleDirection;
 
      // If the excess is smaller than the ecal energy, assign the whole
      // excess to photons
      if (ePhoton < totalEcal || eNeutralHadron - calibEcal < 1E-10) {
        if (!maxEcalRef.isNull()) {
          // So the merged photon energy is,
          mergedPhotonEnergy = ePhoton;
        }
      } else {
        // Otherwise assign the whole ECAL energy to the photons
        if (!maxEcalRef.isNull()) {
          // So the merged photon energy is,
          mergedPhotonEnergy = totalEcalEGMCalib;  // KH: use calibrated ECAL energy under the egamma hypothesis
        }
        // ... and assign the remaining excess to neutral hadrons using the direction of ecal clusters
        mergedNeutralHadronEnergy = eNeutralHadron - calibEcal;
      }
 
      if (mergedPhotonEnergy > 0) {
        // Split merged photon into photons for each energetic ecal cluster (necessary for jet substructure reconstruction)
        // make only one merged photon if less than 2 ecal clusters
        // KH: this part still needs review, after using non-corrected ECAL energy for PF hadron calibrations
        if (ecalClusters.size() <= 1) {
          ecalClusters.clear();
          ecalClusters.emplace_back(
              maxiEcal,
              photonAtECAL,
              1.);  // KH: calibration factor of 1, which should be ok as long as sumEcalClusters is consistent with photonAtECAL in this case
          sumEcalClusters = sqrt(photonAtECAL.Mag2());
        }
        for (auto const& pae : ecalClusters) {
          const double clusterEnergyCalibrated =
              sqrt(std::get<1>(pae).Mag2()) *
              std::get<2>(
                  pae);  // KH: calibrated under the egamma hypothesis. Note: sumEcalClusters is normally calibrated under egamma hypothesis
          particleEnergy.push_back(mergedPhotonEnergy * clusterEnergyCalibrated / sumEcalClusters);
          particleDirection.push_back(std::get<1>(pae));
          ecalEnergy.push_back(mergedPhotonEnergy * clusterEnergyCalibrated / sumEcalClusters);
          hcalEnergy.push_back(0.);
          rawecalEnergy.push_back(totalEcal);
          rawhcalEnergy.push_back(0.);
          pivotalClusterRef.push_back(elements[std::get<0>(pae)].clusterRef());
          iPivotal.push_back(std::get<0>(pae));
        }
      }  // mergedPhotonEnergy > 0
 
      if (mergedNeutralHadronEnergy > 1.0) {
        // Split merged neutral hadrons according to directions of energetic ecal clusters (necessary for jet substructure reconstruction)
        // make only one merged neutral hadron if less than 2 ecal clusters
        if (ecalClusters.size() <= 1) {
          ecalClusters.clear();
          ecalClusters.emplace_back(
              iHcal,
              hadronAtECAL,
              1.);  // KH: calibration factor of 1, which should be ok as long as sumEcalClusters is consistent with photonAtECAL
          sumEcalClusters = sqrt(hadronAtECAL.Mag2());
        }
        for (auto const& pae : ecalClusters) {
          const double clusterEnergyCalibrated =
              sqrt(std::get<1>(pae).Mag2()) *
              std::get<2>(
                  pae);  // KH: calibrated under the egamma hypothesis. Note: sumEcalClusters is normally calibrated under egamma hypothesis
          particleEnergy.push_back(mergedNeutralHadronEnergy * clusterEnergyCalibrated / sumEcalClusters);
          particleDirection.push_back(std::get<1>(pae));
          ecalEnergy.push_back(0.);
          hcalEnergy.push_back(mergedNeutralHadronEnergy * clusterEnergyCalibrated / sumEcalClusters);
          rawecalEnergy.push_back(0.);
          rawhcalEnergy.push_back(totalHcal);
          pivotalClusterRef.push_back(hclusterref);
          iPivotal.push_back(iHcal);
        }
      }  //mergedNeutralHadronEnergy > 1.0
 
      // reconstructing a merged neutral
      // the type of PFCandidate is known from the
      // reference to the pivotal cluster.
 
      for (unsigned iPivot = 0; iPivot < iPivotal.size(); ++iPivot) {
        if (particleEnergy[iPivot] < 0.)
          edm::LogWarning("PFAlgo|createCandidatesHCAL")
              << "ALARM = Negative energy for iPivot=" << iPivot << ", " << particleEnergy[iPivot];
 
        const bool useDirection = true;
        auto& neutral = (*pfCandidates_)[reconstructCluster(*pivotalClusterRef[iPivot],
                                                            particleEnergy[iPivot],
                                                            useDirection,
                                                            particleDirection[iPivot].X(),
                                                            particleDirection[iPivot].Y(),
                                                            particleDirection[iPivot].Z())];
 
        neutral.setEcalEnergy(rawecalEnergy[iPivot], ecalEnergy[iPivot]);
        if (!useHO_) {
          neutral.setHcalEnergy(rawhcalEnergy[iPivot], hcalEnergy[iPivot]);
          neutral.setHoEnergy(0., 0.);
        } else {                              // useHO_
          if (rawhcalEnergy[iPivot] == 0.) {  // photons should be here
            neutral.setHcalEnergy(0., 0.);
            neutral.setHoEnergy(0., 0.);
          } else {
            neutral.setHcalEnergy(max(rawhcalEnergy[iPivot] - totalHO, 0.0),
                                  hcalEnergy[iPivot] * max(1. - totalHO / rawhcalEnergy[iPivot], 0.));
            neutral.setHoEnergy(totalHO, totalHO * hcalEnergy[iPivot] / rawhcalEnergy[iPivot]);
          }
        }
        neutral.setPs1Energy(0.);
        neutral.setPs2Energy(0.);
        neutral.set_mva_nothing_gamma(-1.);
        // neutral.addElement(&elements[iPivotal]);
        // neutral.addElementInBlock(blockref, iPivotal[iPivot]);
        neutral.addElementInBlock(blockref, iHcal);
        for (unsigned iTrack : chargedHadronsInBlock) {
          neutral.addElementInBlock(blockref, iTrack);
          // Assign the position of the track at the ECAL entrance
          const ::math::XYZPointF& chargedPosition =
              dynamic_cast<const reco::PFBlockElementTrack*>(&elements[iTrack])->positionAtECALEntrance();
          neutral.setPositionAtECALEntrance(chargedPosition);
 
          auto myEcals = associatedEcals.equal_range(iTrack);
          for (auto ii = myEcals.first; ii != myEcals.second; ++ii) {
            unsigned iEcal = ii->second.second;
            if (active[iEcal])
              continue;
            neutral.addElementInBlock(blockref, iEcal);
          }
        }
      }
 
    }  // excess of energy
 
    // will now share the hcal energy between the various charged hadron
    // candidates, taking into account the potential neutral hadrons
 
    //JB: The question is: we've resolved the merged photons cleanly, but how should
    //the remaining hadrons be assigned the remaining ecal energy?
    //*Temporary solution*: follow HCAL example with fractions...
 
    // remove the energy of the potential neutral hadron
    double totalHcalEnergyCalibrated = std::max(calibHcal - mergedNeutralHadronEnergy, 0.);
    // similarly for the merged photons
    double totalEcalEnergyCalibrated = std::max(calibEcal - mergedPhotonEnergy, 0.);
    // share between the charged hadrons
 
    //COLIN can compute this before
    // not exactly equal to sum p, this is sum E
    double chargedHadronsTotalEnergy = 0;
    for (unsigned index : chargedHadronsIndices) {
      reco::PFCandidate& chargedHadron = (*pfCandidates_)[index];
      chargedHadronsTotalEnergy += chargedHadron.energy();
    }
 
    for (unsigned index : chargedHadronsIndices) {
      reco::PFCandidate& chargedHadron = (*pfCandidates_)[index];
      float fraction = chargedHadron.energy() / chargedHadronsTotalEnergy;
 
      if (!useHO_) {
        chargedHadron.setHcalEnergy(fraction * totalHcal, fraction * totalHcalEnergyCalibrated);
        chargedHadron.setHoEnergy(0., 0.);
      } else {
        chargedHadron.setHcalEnergy(fraction * max(totalHcal - totalHO, 0.0),
                                    fraction * totalHcalEnergyCalibrated * (1. - totalHO / totalHcal));
        chargedHadron.setHoEnergy(fraction * totalHO, fraction * totalHO * totalHcalEnergyCalibrated / totalHcal);
      }
      //JB: fixing up (previously omitted) setting of ECAL energy gouzevit
      chargedHadron.setEcalEnergy(fraction * totalEcal, fraction * totalEcalEnergyCalibrated);
    }
 
    // Finally treat unused ecal satellites as photons.
    for (auto const& ecalSatellite : ecalSatellites) {
      // Ignore satellites already taken
      unsigned iEcal = std::get<0>(ecalSatellite.second);
      if (!active[iEcal])
        continue;
 
      // Sanity checks again (well not useful, this time!)
      PFBlockElement::Type type = elements[iEcal].type();
      assert(type == PFBlockElement::ECAL);
      PFClusterRef eclusterref = elements[iEcal].clusterRef();
      assert(!eclusterref.isNull());
 
      // Lock the cluster
      active[iEcal] = false;
 
      // Find the associated tracks
      std::multimap<double, unsigned> assTracks;
      block.associatedElements(iEcal, linkData, assTracks, reco::PFBlockElement::TRACK, reco::PFBlock::LINKTEST_ALL);
 
      // Create a photon
      double ecalClusterEnergyCalibrated =
          sqrt(std::get<1>(ecalSatellite.second).Mag2()) *
          std::get<2>(
              ecalSatellite.second);  // KH: calibrated under the egamma hypothesis (rawEcalClusterEnergy * calibration)
      auto& cand = (*pfCandidates_)[reconstructCluster(*eclusterref, ecalClusterEnergyCalibrated)];
      cand.setEcalEnergy(eclusterref->energy(), ecalClusterEnergyCalibrated);
      cand.setHcalEnergy(0., 0.);
      cand.setHoEnergy(0., 0.);
      cand.setPs1Energy(associatedPSs[iEcal].first);
      cand.setPs2Energy(associatedPSs[iEcal].second);
      cand.addElementInBlock(blockref, iEcal);
      cand.addElementInBlock(blockref, sortedTracks.begin()->second);
 
      if (fabs(eclusterref->energy() - sqrt(std::get<1>(ecalSatellite.second).Mag2())) > 1e-3 ||
          fabs(eclusterref->correctedEnergy() - ecalClusterEnergyCalibrated) > 1e-3)
        edm::LogWarning("PFAlgo:processBlock")
            << "ecalCluster vs ecalSatellites look inconsistent (eCluster E, calibE, ecalSatellite E, calib E): "
            << eclusterref->energy() << " " << eclusterref->correctedEnergy() << " "
            << sqrt(std::get<1>(ecalSatellite.second).Mag2()) << " " << ecalClusterEnergyCalibrated;
 
    }  // ecalSatellites
 
  }  // hcalIs
  // end loop on hcal element iHcal= hcalIs[i]
  LogTrace("PFAlgo|createCandidatesHCAL") << "end of function PFAlgo::createCandidatesHCAL";
}
 
void PFAlgo::createCandidatesHCALUnlinked(const reco::PFBlock& block,
                                          reco::PFBlock::LinkData& linkData,
                                          const edm::OwnVector<reco::PFBlockElement>& elements,
                                          std::vector<bool>& active,
                                          const reco::PFBlockRef& blockref,
                                          ElementIndices& inds,
                                          std::vector<bool>& deadArea) {
  // Processing the remaining HCAL clusters
  LogTrace("PFAlgo|createCandidatesHCALUnlinked")
      << "start of function PFAlgo::createCandidatesHCALUnlinked, hcalIs.size()=" << inds.hcalIs.size();
 
  // --------------- loop remaining hcal ------------------
 
  for (unsigned iHcal : inds.hcalIs) {
    // Keep ECAL and HO elements for reference in the PFCandidate
    std::vector<unsigned> ecalRefs;
    std::vector<unsigned> hoRefs;
 
    LogTrace("PFAlgo|createCandidatesHCALUnlinked") << elements[iHcal] << " ";
 
    if (!active[iHcal]) {
      LogTrace("PFAlgo|createCandidatesHCALUnlinked") << "not active " << iHcal;
      continue;
    }
 
    // Find the ECAL elements linked to it
    std::multimap<double, unsigned> ecalElems;
    block.associatedElements(iHcal, linkData, ecalElems, reco::PFBlockElement::ECAL, reco::PFBlock::LINKTEST_ALL);
 
    // Loop on these ECAL elements
    float totalEcal = 0.;
    float ecalMax = 0.;
    reco::PFClusterRef eClusterRef;
    for (auto const& ecal : ecalElems) {
      unsigned iEcal = ecal.second;
      double dist = ecal.first;
      PFBlockElement::Type type = elements[iEcal].type();
      assert(type == PFBlockElement::ECAL);
 
      // Check if already used
      if (!active[iEcal])
        continue;
 
      // Check the distance (one HCALPlusECAL tower, roughly)
      // if ( dist > 0.15 ) continue;
 
      //COLINFEB16
      // what could be done is to
      // - link by rechit.
      // - take in the neutral hadron all the ECAL clusters
      // which are within the same CaloTower, according to the distance,
      // except the ones which are closer to another HCAL cluster.
      // - all the other ECAL linked to this HCAL are photons.
      //
      // about the closest HCAL cluster.
      // it could maybe be easier to loop on the ECAL clusters first
      // to cut the links to all HCAL clusters except the closest, as is
      // done in the first track loop. But maybe not!
      // or add an helper function to the PFAlgo class to ask
      // if a given element is the closest of a given type to another one?
 
      // Check if not closer from another free HCAL
      std::multimap<double, unsigned> hcalElems;
      block.associatedElements(iEcal, linkData, hcalElems, reco::PFBlockElement::HCAL, reco::PFBlock::LINKTEST_ALL);
 
      const bool isClosest = std::none_of(hcalElems.begin(), hcalElems.end(), [&](auto const& hcal) {
        return active[hcal.second] && hcal.first < dist;
      });
 
      if (!isClosest)
        continue;
 
#ifdef EDM_ML_DEBUG
      LogTrace("PFAlgo|createCandidatesHCALUnlinked")
          << "\telement " << elements[iEcal] << " linked with dist " << dist;
      LogTrace("PFAlgo|createCandidatesHCALUnlinked") << "Added to HCAL cluster to form a neutral hadron";
#endif
 
      reco::PFClusterRef eclusterRef = elements[iEcal].clusterRef();
      assert(!eclusterRef.isNull());
 
      // KH: use raw ECAL energy for PF hadron calibration_.
      double ecalEnergy = eclusterRef->energy();  // ecalEnergy = eclusterRef->correctedEnergy();
 
      totalEcal += ecalEnergy;
      if (ecalEnergy > ecalMax) {
        ecalMax = ecalEnergy;
        eClusterRef = eclusterRef;
      }
 
      ecalRefs.push_back(iEcal);
      active[iEcal] = false;
 
    }  // End loop ECAL
 
    // Now find the HO clusters linked to the HCAL cluster
    double totalHO = 0.;
    double hoMax = 0.;
    //unsigned jHO = 0;
    if (useHO_) {
      std::multimap<double, unsigned> hoElems;
      block.associatedElements(iHcal, linkData, hoElems, reco::PFBlockElement::HO, reco::PFBlock::LINKTEST_ALL);
 
      // Loop on these HO elements
      //      double totalHO = 0.;
      //      double hoMax = 0.;
      //      unsigned jHO = 0;
      reco::PFClusterRef hoClusterRef;
      for (auto const& ho : hoElems) {
        unsigned iHO = ho.second;
        double dist = ho.first;
        PFBlockElement::Type type = elements[iHO].type();
        assert(type == PFBlockElement::HO);
 
        // Check if already used
        if (!active[iHO])
          continue;
 
        // Check the distance (one HCALPlusHO tower, roughly)
        // if ( dist > 0.15 ) continue;
 
        // Check if not closer from another free HCAL
        std::multimap<double, unsigned> hcalElems;
        block.associatedElements(iHO, linkData, hcalElems, reco::PFBlockElement::HCAL, reco::PFBlock::LINKTEST_ALL);
 
        const bool isClosest = std::none_of(hcalElems.begin(), hcalElems.end(), [&](auto const& hcal) {
          return active[hcal.second] && hcal.first < dist;
        });
 
        if (!isClosest)
          continue;
 
#ifdef EDM_ML_DEBUG
        if (useHO_) {
          LogTrace("PFAlgo|createCandidatesHCALUnlinked")
              << "\telement " << elements[iHO] << " linked with dist " << dist;
          LogTrace("PFAlgo|createCandidatesHCALUnlinked") << "Added to HCAL cluster to form a neutral hadron";
        }
#endif
 
        reco::PFClusterRef hoclusterRef = elements[iHO].clusterRef();
        assert(!hoclusterRef.isNull());
 
        double hoEnergy =
            hoclusterRef->energy();  // calibration_.energyEm(*hoclusterRef,ps1Ene,ps2Ene,crackCorrection);
 
        totalHO += hoEnergy;
        if (hoEnergy > hoMax) {
          hoMax = hoEnergy;
          hoClusterRef = hoclusterRef;
          //jHO = iHO;
        }
 
        hoRefs.push_back(iHO);
        active[iHO] = false;
 
      }  // End loop HO
    }
 
    PFClusterRef hclusterRef = elements[iHcal].clusterRef();
    assert(!hclusterRef.isNull());
 
    // HCAL energy
    double totalHcal = hclusterRef->energy();
    // Include the HO energy
    if (useHO_)
      totalHcal += totalHO;
 
    // Calibration
    double calibEcal = totalEcal > 0. ? totalEcal : 0.;
    double calibHcal = std::max(0., totalHcal);
    if (hclusterRef->layer() == PFLayer::HF_HAD || hclusterRef->layer() == PFLayer::HF_EM) {
      calibEcal = totalEcal;
    } else {
      calibration_.energyEmHad(
          -1., calibEcal, calibHcal, hclusterRef->positionREP().Eta(), hclusterRef->positionREP().Phi());
    }
 
    auto& cand = (*pfCandidates_)[reconstructCluster(*hclusterRef, calibEcal + calibHcal)];
 
    cand.setEcalEnergy(totalEcal, calibEcal);
    if (!useHO_) {
      cand.setHcalEnergy(totalHcal, calibHcal);
      cand.setHoEnergy(0., 0.);
    } else {
      cand.setHcalEnergy(max(totalHcal - totalHO, 0.0), calibHcal * (1. - totalHO / totalHcal));
      cand.setHoEnergy(totalHO, totalHO * calibHcal / totalHcal);
    }
    cand.setPs1Energy(0.);
    cand.setPs2Energy(0.);
    cand.addElementInBlock(blockref, iHcal);
    for (auto const& ec : ecalRefs)
      cand.addElementInBlock(blockref, ec);
    for (auto const& ho : hoRefs)
      cand.addElementInBlock(blockref, ho);
 
  }  //loop hcal elements
}
 
void PFAlgo::createCandidatesECAL(const reco::PFBlock& block,
                                  reco::PFBlock::LinkData& linkData,
                                  const edm::OwnVector<reco::PFBlockElement>& elements,
                                  std::vector<bool>& active,
                                  const reco::PFBlockRef& blockref,
                                  ElementIndices& inds,
                                  std::vector<bool>& deadArea) {
  LogTrace("PFAlgo|createCandidatesECAL")
      << "start of function PFAlgo::createCandidatesECAL(), ecalIs.size()=" << inds.ecalIs.size();
 
  // --------------- loop ecal ------------------
 
  // for each ecal element iEcal = ecalIs[i] in turn:
 
  for (unsigned i = 0; i < inds.ecalIs.size(); i++) {
    unsigned iEcal = inds.ecalIs[i];
 
    LogTrace("PFAlgo|createCandidatesECAL") << "elements[" << iEcal << "]=" << elements[iEcal];
 
    if (!active[iEcal]) {
      LogTrace("PFAlgo|createCandidatesECAL") << "iEcal=" << iEcal << " not active";
      continue;
    }
 
    PFBlockElement::Type type = elements[iEcal].type();
    assert(type == PFBlockElement::ECAL);
 
    PFClusterRef clusterref = elements[iEcal].clusterRef();
    assert(!clusterref.isNull());
 
    active[iEcal] = false;
 
    float ecalEnergy = clusterref->correctedEnergy();
    // float ecalEnergy = calibration_.energyEm( clusterref->energy() );
    double particleEnergy = ecalEnergy;
 
    auto& cand = (*pfCandidates_)[reconstructCluster(*clusterref, particleEnergy)];
 
    cand.setEcalEnergy(clusterref->energy(), ecalEnergy);
    cand.setHcalEnergy(0., 0.);
    cand.setHoEnergy(0., 0.);
    cand.setPs1Energy(0.);
    cand.setPs2Energy(0.);
    cand.addElementInBlock(blockref, iEcal);
 
  }  // end loop on ecal elements iEcal = ecalIs[i]
  LogTrace("PFAlgo|createCandidatesECAL") << "end of function PFALgo::createCandidatesECAL";
}
 
void PFAlgo::processBlock(const reco::PFBlockRef& blockref,
                          std::list<reco::PFBlockRef>& hcalBlockRefs,
                          std::list<reco::PFBlockRef>& ecalBlockRefs,
                          PFEGammaFilters const* pfegamma) {
  assert(!blockref.isNull());
  const reco::PFBlock& block = *blockref;
 
  LogTrace("PFAlgo|processBlock") << "start of function PFAlgo::processBlock, block=" << block;
 
  const edm::OwnVector<reco::PFBlockElement>& elements = block.elements();
  LogTrace("PFAlgo|processBlock") << "elements.size()=" << elements.size();
  // make a copy of the link data, which will be edited.
  PFBlock::LinkData linkData = block.linkData();
 
  // keep track of the elements which are still active.
  vector<bool> active(elements.size(), true);
 
  // //PFElectrons:
  // usePFElectrons_ external configurable parameter to set the usage of pf electron
  std::vector<reco::PFCandidate> tempElectronCandidates;
  tempElectronCandidates.clear();
 
  // New EGamma Reconstruction 10/10/2013
  if (useEGammaFilters_) {
    egammaFilters(blockref, active, pfegamma);
  }  // end if use EGammaFilters
 
  //Lock extra conversion tracks not used by Photon Algo
  if (usePFConversions_) {
    conversionAlgo(elements, active);
  }
 
  // In the following elementLoop() function, the primary goal is to deal with tracks that are:
  // - not associated to an HCAL cluster
  // - not identified as an electron.
  // Those tracks should be predominantly relatively low energy charged
  // hadrons which are not detected in the ECAL.
 
  // The secondary goal is to prepare for the next loops
  // - The ecal and hcal elements are sorted in separate vectors in `ElementIndices inds`
  // which will be used as a base for the corresponding loops.
  // - For tracks which are connected to more than one HCAL cluster,
  // the links between the track and the cluster are cut for all clusters
  // but the closest one.
  // - HF only blocks ( HFEM, HFHAD, HFEM+HFAD) are identified
 
  // obsolete comments?
  // loop1:
  // - sort ecal and hcal elements in separate vectors
  // - for tracks:
  //       - lock closest ecal cluster
  //       - cut link to farthest hcal cluster, if more than 1.
 
  vector<bool> deadArea(elements.size(), false);
 
  // vectors to store element indices to ho, hcal and ecal elements, will be filled by elementLoop()
  ElementIndices inds;
 
  elementLoop(block, linkData, elements, active, blockref, inds, deadArea);
 
  // Reconstruct pfCandidate from HF (either EM-only, Had-only or both)
  // For phase2, process also pfblocks containing HF clusters and linked tracks
  if (!(inds.hfEmIs.empty() && inds.hfHadIs.empty())) {
    createCandidatesHF(block, linkData, elements, active, blockref, inds);
    if (inds.hcalIs.empty() && inds.ecalIs.empty())
      return;
    LogDebug("PFAlgo::processBlock")
        << "Block contains HF clusters, and also contains ECAL or HCAL clusters. Continue.\n"
        << block;
  }
 
  createCandidatesHCAL(block, linkData, elements, active, blockref, inds, deadArea);
  // COLINFEB16: now dealing with the HCAL elements that are not linked to any track
  createCandidatesHCALUnlinked(block, linkData, elements, active, blockref, inds, deadArea);
  createCandidatesECAL(block, linkData, elements, active, blockref, inds, deadArea);
 
  LogTrace("PFAlgo|processBlock") << "end of function PFAlgo::processBlock";
}  // end processBlock
 
unsigned PFAlgo::reconstructTrack(const reco::PFBlockElement& elt, bool allowLoose) {
  const auto* eltTrack = dynamic_cast<const reco::PFBlockElementTrack*>(&elt);
 
  const reco::TrackRef& trackRef = eltTrack->trackRef();
  const reco::Track& track = *trackRef;
  const reco::MuonRef& muonRef = eltTrack->muonRef();
  int charge = track.charge() > 0 ? 1 : -1;
 
  // Assume this particle is a charged Hadron
  double px = track.px();
  double py = track.py();
  double pz = track.pz();
  double energy = sqrt(track.p() * track.p() + 0.13957 * 0.13957);
 
  LogTrace("PFAlgo|reconstructTrack") << "Reconstructing PF candidate from track of pT = " << track.pt()
                                      << " eta = " << track.eta() << " phi = " << track.phi() << " px = " << px
                                      << " py = " << py << " pz = " << pz << " energy = " << energy;
 
  // Create a PF Candidate
  ::math::XYZTLorentzVector momentum(px, py, pz, energy);
  reco::PFCandidate::ParticleType particleType = reco::PFCandidate::h;
 
  // Add it to the stack
  LogTrace("PFAlgo|reconstructTrack") << "Creating PFCandidate charge=" << charge << ", type=" << particleType
                                      << ", pt=" << momentum.pt() << ", eta=" << momentum.eta()
                                      << ", phi=" << momentum.phi();
  pfCandidates_->push_back(PFCandidate(charge, momentum, particleType));
  //Set vertex and stuff like this
  pfCandidates_->back().setVertex(trackRef->vertex());
  pfCandidates_->back().setTrackRef(trackRef);
  pfCandidates_->back().setPositionAtECALEntrance(eltTrack->positionAtECALEntrance());
  if (muonRef.isNonnull())
    pfCandidates_->back().setMuonRef(muonRef);
 
  //Set time
  if (elt.isTimeValid())
    pfCandidates_->back().setTime(elt.time(), elt.timeError());
 
  //OK Now try to reconstruct the particle as a muon
  bool isMuon = pfmu_->reconstructMuon(pfCandidates_->back(), muonRef, allowLoose);
  bool isFromDisp = isFromSecInt(elt, "secondary");
 
  if ((!isMuon) && isFromDisp) {
    double dpt = trackRef->ptError();
    double dptRel = dpt / trackRef->pt() * 100;
    //If the track is ill measured it is better to not refit it, since the track information probably would not be used.
    //In the PFAlgo we use the trackref information. If the track error is too big the refitted information might be very different
    // from the not refitted one.
    if (dptRel < dptRel_DispVtx_) {
      LogTrace("PFAlgo|reconstructTrack")
          << "Not refitted px = " << px << " py = " << py << " pz = " << pz << " energy = " << energy;
      //reco::TrackRef trackRef = eltTrack->trackRef();
      reco::PFDisplacedVertexRef vRef =
          eltTrack->displacedVertexRef(reco::PFBlockElement::T_FROM_DISP)->displacedVertexRef();
      reco::Track trackRefit = vRef->refittedTrack(trackRef);
      //change the momentum with the refitted track
      ::math::XYZTLorentzVector momentum(
          trackRefit.px(), trackRefit.py(), trackRefit.pz(), sqrt(trackRefit.p() * trackRefit.p() + 0.13957 * 0.13957));
      LogTrace("PFAlgo|reconstructTrack")
          << "Refitted px = " << px << " py = " << py << " pz = " << pz << " energy = " << energy;
    }
    pfCandidates_->back().setFlag(reco::PFCandidate::T_FROM_DISP, true);
    pfCandidates_->back().setDisplacedVertexRef(
        eltTrack->displacedVertexRef(reco::PFBlockElement::T_FROM_DISP)->displacedVertexRef(),
        reco::PFCandidate::T_FROM_DISP);
  }
 
  // do not label as primary a track which would be recognised as a muon. A muon cannot produce NI. It is with high probability a fake
  if (isFromSecInt(elt, "primary") && !isMuon) {
    pfCandidates_->back().setFlag(reco::PFCandidate::T_TO_DISP, true);
    pfCandidates_->back().setDisplacedVertexRef(
        eltTrack->displacedVertexRef(reco::PFBlockElement::T_TO_DISP)->displacedVertexRef(),
        reco::PFCandidate::T_TO_DISP);
  }
 
  // returns index to the newly created PFCandidate
  return pfCandidates_->size() - 1;
}
 
unsigned PFAlgo::reconstructCluster(const reco::PFCluster& cluster,
                                    double particleEnergy,
                                    bool useDirection,
                                    double particleX,
                                    double particleY,
                                    double particleZ) {
  LogTrace("PFAlgo|reconstructCluster") << "start of function PFAlgo::reconstructCluster, cluster=" << cluster
                                        << "particleEnergy=" << particleEnergy << "useDirection=" << useDirection
                                        << "particleX=" << particleX << "particleY=" << particleY
                                        << "particleZ=" << particleZ;
 
  reco::PFCandidate::ParticleType particleType = reco::PFCandidate::X;
 
  // need to convert the ::math::XYZPoint data member of the PFCluster class=
  // to a displacement vector:
 
  // Transform particleX,Y,Z to a position at ECAL/HCAL entrance
  double factor = 1.;
  if (useDirection) {
    switch (cluster.layer()) {
      case PFLayer::ECAL_BARREL:
      case PFLayer::HCAL_BARREL1:
        factor = std::sqrt(cluster.position().Perp2() / (particleX * particleX + particleY * particleY));
        break;
      case PFLayer::ECAL_ENDCAP:
      case PFLayer::HCAL_ENDCAP:
      case PFLayer::HF_HAD:
      case PFLayer::HF_EM:
        factor = cluster.position().Z() / particleZ;
        break;
      default:
        assert(0);
    }
  }
  //MIKE First of all let's check if we have vertex.
  ::math::XYZPoint vertexPos;
  if (useVertices_)
    vertexPos = ::math::XYZPoint(primaryVertex_.x(), primaryVertex_.y(), primaryVertex_.z());
  else
    vertexPos = ::math::XYZPoint(0.0, 0.0, 0.0);
 
  ::math::XYZVector clusterPos(cluster.position().X() - vertexPos.X(),
                               cluster.position().Y() - vertexPos.Y(),
                               cluster.position().Z() - vertexPos.Z());
  ::math::XYZVector particleDirection(
      particleX * factor - vertexPos.X(), particleY * factor - vertexPos.Y(), particleZ * factor - vertexPos.Z());
 
  //::math::XYZVector clusterPos( cluster.position().X(), cluster.position().Y(),cluster.position().Z() );
  //::math::XYZVector particleDirection ( particleX, particleY, particleZ );
 
  clusterPos = useDirection ? particleDirection.Unit() : clusterPos.Unit();
  clusterPos *= particleEnergy;
 
  // clusterPos is now a vector along the cluster direction,
  // with a magnitude equal to the cluster energy.
 
  double mass = 0;
  ROOT::Math::LorentzVector<ROOT::Math::PxPyPzM4D<double>> momentum(
      clusterPos.X(), clusterPos.Y(), clusterPos.Z(), mass);
  // mathcore is a piece of #$%
  ::math::XYZTLorentzVector tmp;
  // implicit constructor not allowed
  tmp = momentum;
 
  // Charge
  int charge = 0;
 
  // Type
  switch (cluster.layer()) {
    case PFLayer::ECAL_BARREL:
    case PFLayer::ECAL_ENDCAP:
      particleType = PFCandidate::gamma;
      break;
    case PFLayer::HCAL_BARREL1:
    case PFLayer::HCAL_ENDCAP:
      particleType = PFCandidate::h0;
      break;
    case PFLayer::HF_HAD:
      particleType = PFCandidate::h_HF;
      break;
    case PFLayer::HF_EM:
      particleType = PFCandidate::egamma_HF;
      break;
    default:
      assert(0);
  }
 
  // The pf candidate
  LogTrace("PFAlgo|reconstructCluster") << "Creating PFCandidate charge=" << charge << ", type=" << particleType
                                        << ", pt=" << tmp.pt() << ", eta=" << tmp.eta() << ", phi=" << tmp.phi();
  pfCandidates_->push_back(PFCandidate(charge, tmp, particleType));
 
  // The position at ECAL entrance (well: watch out, it is not true
  // for HCAL clusters... to be fixed)
  pfCandidates_->back().setPositionAtECALEntrance(
      ::math::XYZPointF(cluster.position().X(), cluster.position().Y(), cluster.position().Z()));
 
  //Set the cnadidate Vertex
  pfCandidates_->back().setVertex(vertexPos);
 
  // depth info
  setHcalDepthInfo(pfCandidates_->back(), cluster);
 
  //*TODO* cluster time is not reliable at the moment, so only use track timing
 
  LogTrace("PFAlgo|reconstructCluster") << "** candidate: " << pfCandidates_->back();
 
  // returns index to the newly created PFCandidate
  return pfCandidates_->size() - 1;
}
 
void PFAlgo::setHcalDepthInfo(reco::PFCandidate& cand, const reco::PFCluster& cluster) const {
  std::array<double, 7> energyPerDepth;
  std::fill(energyPerDepth.begin(), energyPerDepth.end(), 0.0);
  for (auto& hitRefAndFrac : cluster.recHitFractions()) {
    const auto& hit = *hitRefAndFrac.recHitRef();
    if (DetId(hit.detId()).det() == DetId::Hcal) {
      if (hit.depth() == 0) {
        edm::LogWarning("setHcalDepthInfo") << "Depth zero found";
        continue;
      }
      if (hit.depth() < 1 || hit.depth() > 7) {
        throw cms::Exception("CorruptData") << "Bogus depth " << hit.depth() << " at detid " << hit.detId() << "\n";
      }
      energyPerDepth[hit.depth() - 1] += hitRefAndFrac.fraction() * hit.energy();
    }
  }
  double sum = std::accumulate(energyPerDepth.begin(), energyPerDepth.end(), 0.);
  std::array<float, 7> depthFractions;
  if (sum > 0) {
    for (unsigned int i = 0; i < depthFractions.size(); ++i) {
      depthFractions[i] = energyPerDepth[i] / sum;
    }
  } else {
    std::fill(depthFractions.begin(), depthFractions.end(), 0.f);
  }
  cand.setHcalDepthEnergyFractions(depthFractions);
}
 
//GMA need the followign two for HO also
 
double PFAlgo::neutralHadronEnergyResolution(double clusterEnergyHCAL, double eta) const {
  // Add a protection
  clusterEnergyHCAL = std::max(clusterEnergyHCAL, 1.);
 
  double resol = fabs(eta) < 1.48 ? sqrt(1.02 * 1.02 / clusterEnergyHCAL + 0.065 * 0.065)
                                  : sqrt(1.20 * 1.20 / clusterEnergyHCAL + 0.028 * 0.028);
 
  return resol;
}
 
double PFAlgo::nSigmaHCAL(double clusterEnergyHCAL, double eta) const {
  double nS = fabs(eta) < 1.48 ? nSigmaHCAL_ * (1. + exp(-clusterEnergyHCAL / nSigmaEConstHCAL))
                               : nSigmaHCAL_ * (1. + exp(-clusterEnergyHCAL / nSigmaEConstHCAL));
 
  return nS;
}
 
double PFAlgo::hfEnergyResolution(double clusterEnergyHF) const {
  // Add a protection
  clusterEnergyHF = std::max(clusterEnergyHF, 1.);
 
  double resol =
      sqrt(resolHF_square_[0] / clusterEnergyHF + resolHF_square_[1] + resolHF_square_[2] / pow(clusterEnergyHF, 2));
  // 0: stochastic term, 1: constant term, 2: noise term
  // Note: resolHF_square_[0,1,2] should be already squared
 
  return resol;
}
 
double PFAlgo::nSigmaHFEM(double clusterEnergyHF) const {
  double nS = nSigmaHFEM_ * (1. + exp(-clusterEnergyHF / nSigmaEConstHFEM));
  return nS;
}
 
double PFAlgo::nSigmaHFHAD(double clusterEnergyHF) const {
  double nS = nSigmaHFHAD_ * (1. + exp(-clusterEnergyHF / nSigmaEConstHFHAD));
  return nS;
}
 
ostream& operator<<(ostream& out, const PFAlgo& algo) {
  if (!out)
    return out;
 
  out << "====== Particle Flow Algorithm ======= ";
  out << endl;
  out << "nSigmaECAL_     " << algo.nSigmaECAL_ << endl;
  out << "nSigmaHCAL_     " << algo.nSigmaHCAL_ << endl;
  out << "nSigmaHFEM_     " << algo.nSigmaHFEM_ << endl;
  out << "nSigmaHFHAD_    " << algo.nSigmaHFHAD_ << endl;
  out << endl;
  out << algo.calibration_ << endl;
  out << endl;
  out << "reconstructed particles: " << endl;
 
  if (!algo.pfCandidates_.get()) {
    out << "candidates already transfered" << endl;
    return out;
  }
  for (auto const& c : *algo.pfCandidates_)
    out << c << endl;
 
  return out;
}
 
void PFAlgo::associatePSClusters(unsigned iEcal,
                                 reco::PFBlockElement::Type psElementType,
                                 const reco::PFBlock& block,
                                 const edm::OwnVector<reco::PFBlockElement>& elements,
                                 const reco::PFBlock::LinkData& linkData,
                                 std::vector<bool>& active,
                                 std::vector<double>& psEne) {
  // Find all PS clusters with type psElement associated to ECAL cluster iEcal,
  // within all PFBlockElement "elements" of a given PFBlock "block"
  // psElement can be reco::PFBlockElement::PS1 or reco::PFBlockElement::PS2
  // Returns a vector of PS cluster energies, and updates the "active" vector.
 
  // Find all PS clusters linked to the iEcal cluster
  std::multimap<double, unsigned> sortedPS;
  block.associatedElements(iEcal, linkData, sortedPS, psElementType, reco::PFBlock::LINKTEST_ALL);
 
  // Loop over these PS clusters
  double totalPS = 0.;
  for (auto const& ps : sortedPS) {
    // CLuster index and distance to iEcal
    unsigned iPS = ps.second;
    // double distPS = ps.first;
 
    // Ignore clusters already in use
    if (!active[iPS])
      continue;
 
    // Check that this cluster is not closer to another ECAL cluster
    std::multimap<double, unsigned> sortedECAL;
    block.associatedElements(iPS, linkData, sortedECAL, reco::PFBlockElement::ECAL, reco::PFBlock::LINKTEST_ALL);
    unsigned jEcal = sortedECAL.begin()->second;
    if (jEcal != iEcal)
      continue;
 
    // Update PS energy
    PFBlockElement::Type pstype = elements[iPS].type();
    assert(pstype == psElementType);
    PFClusterRef psclusterref = elements[iPS].clusterRef();
    assert(!psclusterref.isNull());
    totalPS += psclusterref->energy();
    psEne[0] += psclusterref->energy();
    active[iPS] = false;
  }
}
 
bool PFAlgo::isFromSecInt(const reco::PFBlockElement& eTrack, string order) const {
  reco::PFBlockElement::TrackType T_TO_DISP = reco::PFBlockElement::T_TO_DISP;
  reco::PFBlockElement::TrackType T_FROM_DISP = reco::PFBlockElement::T_FROM_DISP;
  //  reco::PFBlockElement::TrackType T_FROM_GAMMACONV = reco::PFBlockElement::T_FROM_GAMMACONV;
  reco::PFBlockElement::TrackType T_FROM_V0 = reco::PFBlockElement::T_FROM_V0;
 
  bool bPrimary = (order.find("primary") != string::npos);
  bool bSecondary = (order.find("secondary") != string::npos);
  bool bAll = (order.find("all") != string::npos);
 
  bool isToDisp = usePFNuclearInteractions_ && eTrack.trackType(T_TO_DISP);
  bool isFromDisp = usePFNuclearInteractions_ && eTrack.trackType(T_FROM_DISP);
 
  if (bPrimary && isToDisp)
    return true;
  if (bSecondary && isFromDisp)
    return true;
  if (bAll && (isToDisp || isFromDisp))
    return true;
 
  //   bool isFromConv = usePFConversions_ && eTrack.trackType(T_FROM_GAMMACONV);
 
  //   if ((bAll || bSecondary)&& isFromConv) return true;
 
  bool isFromDecay = (bAll || bSecondary) && usePFDecays_ && eTrack.trackType(T_FROM_V0);
 
  return isFromDecay;
}
 
void PFAlgo::postCleaning() {
  //Compute met and met significance (met/sqrt(SumEt))
  double metX = 0.;
  double metY = 0.;
  double sumet = 0;
  std::vector<unsigned int> pfCandidatesToBeRemoved;
  for (auto const& pfc : *pfCandidates_) {
    metX += pfc.px();
    metY += pfc.py();
    sumet += pfc.pt();
  }
  double met2 = metX * metX + metY * metY;
  // Select events with large MET significance.
  double significance = std::sqrt(met2 / sumet);
  double significanceCor = significance;
  if (significance > minSignificance_) {
    double metXCor = metX;
    double metYCor = metY;
    double sumetCor = sumet;
    double met2Cor = met2;
    double deltaPhi = 3.14159;
    double deltaPhiPt = 100.;
    bool next = true;
    unsigned iCor = 1E9;
 
    // Find the HF candidate with the largest effect on the MET
    while (next) {
      double metReduc = -1.;
      // Loop on the candidates
      for (unsigned i = 0; i < pfCandidates_->size(); ++i) {
        const PFCandidate& pfc = (*pfCandidates_)[i];
 
        // Check that the pfCandidate is in the HF
        if (pfc.particleId() != reco::PFCandidate::h_HF && pfc.particleId() != reco::PFCandidate::egamma_HF)
          continue;
 
        // Check if has meaningful pt
        if (pfc.pt() < minHFCleaningPt_)
          continue;
 
        // Check that it is  not already scheculed to be cleaned
        const bool skip = std::any_of(
            pfCandidatesToBeRemoved.begin(), pfCandidatesToBeRemoved.end(), [&](unsigned int j) { return i == j; });
        if (skip)
          continue;
 
        // Check that the pt and the MET are aligned
        deltaPhi = std::acos((metX * pfc.px() + metY * pfc.py()) / (pfc.pt() * std::sqrt(met2)));
        deltaPhiPt = deltaPhi * pfc.pt();
        if (deltaPhiPt > maxDeltaPhiPt_)
          continue;
 
        // Now remove the candidate from the MET
        double metXInt = metX - pfc.px();
        double metYInt = metY - pfc.py();
        double sumetInt = sumet - pfc.pt();
        double met2Int = metXInt * metXInt + metYInt * metYInt;
        if (met2Int < met2Cor) {
          metXCor = metXInt;
          metYCor = metYInt;
          metReduc = (met2 - met2Int) / met2Int;
          met2Cor = met2Int;
          sumetCor = sumetInt;
          significanceCor = std::sqrt(met2Cor / sumetCor);
          iCor = i;
        }
      }
      //
      // If the MET must be significanly reduced, schedule the candidate to be cleaned
      if (metReduc > minDeltaMet_) {
        pfCandidatesToBeRemoved.push_back(iCor);
        metX = metXCor;
        metY = metYCor;
        sumet = sumetCor;
        met2 = met2Cor;
      } else {
        // Otherwise just stop the loop
        next = false;
      }
    }
    //
    // The significance must be significantly reduced to indeed clean the candidates
    if (significance - significanceCor > minSignificanceReduction_ && significanceCor < maxSignificance_) {
      edm::LogInfo("PFAlgo|postCleaning") << "Significance reduction = " << significance << " -> " << significanceCor
                                          << " = " << significanceCor - significance;
      for (unsigned int toRemove : pfCandidatesToBeRemoved) {
        edm::LogInfo("PFAlgo|postCleaning") << "Removed : " << (*pfCandidates_)[toRemove];
        pfCleanedCandidates_.push_back((*pfCandidates_)[toRemove]);
        (*pfCandidates_)[toRemove].rescaleMomentum(1E-6);
        //reco::PFCandidate::ParticleType unknown = reco::PFCandidate::X;
        //(*pfCandidates_)[toRemove].setParticleType(unknown);
      }
    }
  }  //significance
}  //postCleaning
 
void PFAlgo::checkCleaning(const reco::PFRecHitCollection& cleanedHits) {
  // No hits to recover, leave.
  if (cleanedHits.empty())
    return;
 
  //Compute met and met significance (met/sqrt(SumEt))
  double metX = 0.;
  double metY = 0.;
  double sumet = 0;
  std::vector<unsigned int> hitsToBeAdded;
  for (auto const& pfc : *pfCandidates_) {
    metX += pfc.px();
    metY += pfc.py();
    sumet += pfc.pt();
  }
  double met2 = metX * metX + metY * metY;
  double met2_Original = met2;
  // Select events with large MET significance.
  // double significance = std::sqrt(met2/sumet);
  // double significanceCor = significance;
  double metXCor = metX;
  double metYCor = metY;
  double sumetCor = sumet;
  double met2Cor = met2;
  bool next = true;
  unsigned iCor = 1E9;
 
  // Find the cleaned hit with the largest effect on the MET
  while (next) {
    double metReduc = -1.;
    // Loop on the candidates
    for (unsigned i = 0; i < cleanedHits.size(); ++i) {
      const PFRecHit& hit = cleanedHits[i];
      double length = std::sqrt(hit.position().mag2());
      double px = hit.energy() * hit.position().x() / length;
      double py = hit.energy() * hit.position().y() / length;
      double pt = std::sqrt(px * px + py * py);
 
      // Check that it is  not already scheculed to be cleaned
      bool skip = false;
      for (unsigned int hitIdx : hitsToBeAdded) {
        if (i == hitIdx)
          skip = true;
        if (skip)
          break;
      }
      if (skip)
        continue;
 
      // Now add the candidate to the MET
      double metXInt = metX + px;
      double metYInt = metY + py;
      double sumetInt = sumet + pt;
      double met2Int = metXInt * metXInt + metYInt * metYInt;
 
      // And check if it could contribute to a MET reduction
      if (met2Int < met2Cor) {
        metXCor = metXInt;
        metYCor = metYInt;
        metReduc = (met2 - met2Int) / met2Int;
        met2Cor = met2Int;
        sumetCor = sumetInt;
        // significanceCor = std::sqrt(met2Cor/sumetCor);
        iCor = i;
      }
    }
    //
    // If the MET must be significanly reduced, schedule the candidate to be added
    //
    if (metReduc > minDeltaMet_) {
      hitsToBeAdded.push_back(iCor);
      metX = metXCor;
      metY = metYCor;
      sumet = sumetCor;
      met2 = met2Cor;
    } else {
      // Otherwise just stop the loop
      next = false;
    }
  }
  //
  // At least 10 GeV MET reduction
  if (std::sqrt(met2_Original) - std::sqrt(met2) > 5.) {
    LogTrace("PFAlgo|checkCleaning") << hitsToBeAdded.size() << " hits were re-added ";
    LogTrace("PFAlgo|checkCleaning") << "MET reduction = " << std::sqrt(met2_Original) << " -> " << std::sqrt(met2Cor)
                                     << " = " << std::sqrt(met2Cor) - std::sqrt(met2_Original);
    LogTrace("PFAlgo|checkCleaning") << "Added after cleaning check : ";
    for (unsigned int hitIdx : hitsToBeAdded) {
      const PFRecHit& hit = cleanedHits[hitIdx];
      PFCluster cluster(hit.layer(), hit.energy(), hit.position().x(), hit.position().y(), hit.position().z());
      reconstructCluster(cluster, hit.energy());
      LogTrace("PFAlgo|checkCleaning") << pfCandidates_->back() << ". time = " << hit.time();
    }
  }
}  //PFAlgo::checkCleaning