PileUpSubtractor.cc

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#include "RecoJets/JetProducers/interface/PileUpSubtractor.h"

#include "DataFormats/Common/interface/View.h"
#include "DataFormats/Common/interface/Handle.h"
#include "FWCore/Framework/interface/ESHandle.h"
#include "FWCore/MessageLogger/interface/MessageLogger.h"

#include "DataFormats/Candidate/interface/CandidateFwd.h"
#include "DataFormats/Candidate/interface/Candidate.h"
#include "DataFormats/Math/interface/deltaR.h"
#include "Geometry/CaloGeometry/interface/CaloGeometry.h"
#include "Geometry/Records/interface/CaloGeometryRecord.h"

#include <map>
#include <memory>

using namespace std;

PileUpSubtractor::PileUpSubtractor(const edm::ParameterSet& iConfig, edm::ConsumesCollector&& iC) {
  geo_ = nullptr;
  geoToken_ = iC.esConsumes();
  doAreaFastjet_ = iConfig.getParameter<bool>("doAreaFastjet");
  doRhoFastjet_ = iConfig.getParameter<bool>("doRhoFastjet");
  nSigmaPU_ = iConfig.getParameter<double>("nSigmaPU");
  radiusPU_ = iConfig.getParameter<double>("radiusPU");
  jetPtMin_ = iConfig.getParameter<double>("jetPtMin");
  puPtMin_ = iConfig.getParameter<double>("puPtMin");
  ghostEtaMax = iConfig.getParameter<double>("Ghost_EtaMax");
  activeAreaRepeats = iConfig.getParameter<int>("Active_Area_Repeats");
  ghostArea = iConfig.getParameter<double>("GhostArea");

  if (doAreaFastjet_ || doRhoFastjet_) {
    fjActiveArea_ = std::make_shared<fastjet::ActiveAreaSpec>(ghostEtaMax, activeAreaRepeats, ghostArea);
    if ((ghostEtaMax < 0) || (activeAreaRepeats < 0) || (ghostArea < 0))
      throw cms::Exception("doAreaFastjet or doRhoFastjet")
          << "Parameters ghostEtaMax, activeAreaRepeats or ghostArea for doAreaFastjet/doRhoFastjet are not defined."
          << std::endl;
  }
}

void PileUpSubtractor::reset(std::vector<edm::Ptr<reco::Candidate> >& input,
                             std::vector<fastjet::PseudoJet>& towers,
                             std::vector<fastjet::PseudoJet>& output) {
  inputs_ = &input;
  fjInputs_ = &towers;
  fjJets_ = &output;
  fjOriginalInputs_ = (*fjInputs_);
  for (unsigned int i = 0; i < fjInputs_->size(); ++i) {
    fjOriginalInputs_[i].set_user_index((*fjInputs_)[i].user_index());
  }
}

void PileUpSubtractor::setDefinition(JetDefPtr const& jetDef) {
  fjJetDefinition_ = std::make_shared<fastjet::JetDefinition>(*jetDef);
}

void PileUpSubtractor::setupGeometryMap(edm::Event& iEvent, const edm::EventSetup& iSetup) {
  LogDebug("PileUpSubtractor") << "The subtractor setting up geometry...\n";

  if (geo_ == nullptr) {
    geo_ = &iSetup.getData(geoToken_);
    std::vector<DetId> alldid = geo_->getValidDetIds();

    int ietaold = -10000;
    ietamax_ = -10000;
    ietamin_ = 10000;
    for (std::vector<DetId>::const_iterator did = alldid.begin(); did != alldid.end(); did++) {
      if ((*did).det() == DetId::Hcal) {
        HcalDetId hid = HcalDetId(*did);
        allgeomid_.push_back(*did);

        if (hid.ieta() != ietaold) {
          ietaold = hid.ieta();
          geomtowers_[hid.ieta()] = 1;
          if (hid.ieta() > ietamax_)
            ietamax_ = hid.ieta();
          if (hid.ieta() < ietamin_)
            ietamin_ = hid.ieta();
        } else {
          geomtowers_[hid.ieta()]++;
        }
      }
    }
  }

  for (int i = ietamin_; i < ietamax_ + 1; i++) {
    ntowersWithJets_[i] = 0;
  }
}

//
// Calculate mean E and sigma from jet collection "coll".
//
void PileUpSubtractor::calculatePedestal(vector<fastjet::PseudoJet> const& coll) {
  LogDebug("PileUpSubtractor") << "The subtractor calculating pedestals...\n";
  map<int, double> emean2;
  map<int, int> ntowers;

  int ietaold = -10000;
  int ieta0 = -100;

  // Initial values for emean_, emean2, esigma_, ntowers

  for (int i = ietamin_; i < ietamax_ + 1; i++) {
    emean_[i] = 0.;
    emean2[i] = 0.;
    esigma_[i] = 0.;
    ntowers[i] = 0;
  }

  for (vector<fastjet::PseudoJet>::const_iterator input_object = coll.begin(), fjInputsEnd = coll.end();
       input_object != fjInputsEnd;
       ++input_object) {
    const reco::CandidatePtr& originalTower = (*inputs_)[input_object->user_index()];
    ieta0 = ieta(originalTower);
    double Original_Et = originalTower->et();
    if (ieta0 - ietaold != 0) {
      emean_[ieta0] = emean_[ieta0] + Original_Et;
      emean2[ieta0] = emean2[ieta0] + Original_Et * Original_Et;
      ntowers[ieta0] = 1;
      ietaold = ieta0;
    } else {
      emean_[ieta0] = emean_[ieta0] + Original_Et;
      emean2[ieta0] = emean2[ieta0] + Original_Et * Original_Et;
      ntowers[ieta0]++;
    }
  }

  for (map<int, int>::const_iterator gt = geomtowers_.begin(); gt != geomtowers_.end(); gt++) {
    int it = (*gt).first;

    double e1 = (*(emean_.find(it))).second;
    double e2 = (*emean2.find(it)).second;
    int nt = (*gt).second - (*(ntowersWithJets_.find(it))).second;

    LogDebug("PileUpSubtractor") << " ieta : " << it << " number of towers : " << nt << " e1 : " << e1 << " e2 : " << e2
                                 << "\n";
    if (nt > 0) {
      emean_[it] = e1 / nt;
      double eee = e2 / nt - e1 * e1 / (nt * nt);
      if (eee < 0.)
        eee = 0.;
      esigma_[it] = nSigmaPU_ * sqrt(eee);
    } else {
      emean_[it] = 0.;
      esigma_[it] = 0.;
    }
    LogDebug("PileUpSubtractor") << " ieta : " << it << " Pedestals : " << emean_[it] << "  " << esigma_[it] << "\n";
  }
}

//
// Subtract mean and sigma from fjInputs_
//
void PileUpSubtractor::subtractPedestal(vector<fastjet::PseudoJet>& coll) {
  LogDebug("PileUpSubtractor") << "The subtractor subtracting pedestals...\n";

  int it = -100;
  for (vector<fastjet::PseudoJet>::iterator input_object = coll.begin(), fjInputsEnd = coll.end();
       input_object != fjInputsEnd;
       ++input_object) {
    reco::CandidatePtr const& itow = (*inputs_)[input_object->user_index()];

    it = ieta(itow);

    double etnew = itow->et() - (*(emean_.find(it))).second - (*(esigma_.find(it))).second;
    float mScale = etnew / input_object->Et();
    if (etnew < 0.)
      mScale = 0.;

    math::XYZTLorentzVectorD towP4(input_object->px() * mScale,
                                   input_object->py() * mScale,
                                   input_object->pz() * mScale,
                                   input_object->e() * mScale);

    int index = input_object->user_index();
    input_object->reset_momentum(towP4.px(), towP4.py(), towP4.pz(), towP4.energy());
    input_object->set_user_index(index);
  }
}

void PileUpSubtractor::calculateOrphanInput(vector<fastjet::PseudoJet>& orphanInput) {
  LogDebug("PileUpSubtractor") << "The subtractor calculating orphan input...\n";

  (*fjInputs_) = fjOriginalInputs_;

  vector<int> jettowers;                   // vector of towers indexed by "user_index"
  vector<pair<int, int> > excludedTowers;  // vector of excluded ieta, iphi values

  vector<fastjet::PseudoJet>::iterator pseudojetTMP = fjJets_->begin(), fjJetsEnd = fjJets_->end();
  for (; pseudojetTMP != fjJetsEnd; ++pseudojetTMP) {
    if (pseudojetTMP->perp() < puPtMin_)
      continue;

    // find towers within radiusPU_ of this jet
    for (vector<HcalDetId>::const_iterator im = allgeomid_.begin(); im != allgeomid_.end(); im++) {
      double dr = reco::deltaR(geo_->getPosition((DetId)(*im)), (*pseudojetTMP));
      vector<pair<int, int> >::const_iterator exclude =
          find(excludedTowers.begin(), excludedTowers.end(), pair<int, int>(im->ieta(), im->iphi()));
      if (dr < radiusPU_ && exclude == excludedTowers.end()) {
        ntowersWithJets_[(*im).ieta()]++;
        excludedTowers.push_back(pair<int, int>(im->ieta(), im->iphi()));
      }
    }
    vector<fastjet::PseudoJet>::const_iterator it = fjInputs_->begin(), fjInputsEnd = fjInputs_->end();

    for (; it != fjInputsEnd; ++it) {
      int index = it->user_index();
      int ie = ieta((*inputs_)[index]);
      int ip = iphi((*inputs_)[index]);
      vector<pair<int, int> >::const_iterator exclude =
          find(excludedTowers.begin(), excludedTowers.end(), pair<int, int>(ie, ip));
      if (exclude != excludedTowers.end()) {
        jettowers.push_back(index);
      }  //dr < radiusPU_
    }  // initial input collection
  }  // pseudojets

  //
  // Create a new collections from the towers not included in jets
  //
  for (vector<fastjet::PseudoJet>::const_iterator it = fjInputs_->begin(), fjInputsEnd = fjInputs_->end();
       it != fjInputsEnd;
       ++it) {
    int index = it->user_index();
    vector<int>::const_iterator itjet = find(jettowers.begin(), jettowers.end(), index);
    if (itjet == jettowers.end()) {
      const reco::CandidatePtr& originalTower = (*inputs_)[index];
      fastjet::PseudoJet orphan(originalTower->px(), originalTower->py(), originalTower->pz(), originalTower->energy());
      orphan.set_user_index(index);

      orphanInput.push_back(orphan);
    }
  }
}

void PileUpSubtractor::offsetCorrectJets() {
  LogDebug("PileUpSubtractor") << "The subtractor correcting jets...\n";
  jetOffset_.clear();
  using namespace reco;

  //
  // Reestimate energy of jet (energy of jet with initial map)
  //
  jetOffset_.reserve(fjJets_->size());
  vector<fastjet::PseudoJet>::iterator pseudojetTMP = fjJets_->begin(), jetsEnd = fjJets_->end();
  for (; pseudojetTMP != jetsEnd; ++pseudojetTMP) {
    int ijet = pseudojetTMP - fjJets_->begin();
    jetOffset_[ijet] = 0;

    std::vector<fastjet::PseudoJet> towers = fastjet::sorted_by_pt(pseudojetTMP->constituents());
    double newjetet = 0.;
    for (vector<fastjet::PseudoJet>::const_iterator ito = towers.begin(), towEnd = towers.end(); ito != towEnd; ++ito) {
      const reco::CandidatePtr& originalTower = (*inputs_)[ito->user_index()];
      int it = ieta(originalTower);
      double Original_Et = originalTower->et();
      double etnew = Original_Et - (*emean_.find(it)).second - (*esigma_.find(it)).second;
      if (etnew < 0.)
        etnew = 0;
      newjetet = newjetet + etnew;
      jetOffset_[ijet] += Original_Et - etnew;
    }
    double mScale = newjetet / pseudojetTMP->Et();
    LogDebug("PileUpSubtractor") << "pseudojetTMP->Et() : " << pseudojetTMP->Et() << '\n';
    LogDebug("PileUpSubtractor") << "newjetet : " << newjetet << '\n';
    LogDebug("PileUpSubtractor") << "jetOffset_[ijet] : " << jetOffset_[ijet] << '\n';
    LogDebug("PileUpSubtractor") << "pseudojetTMP->Et() - jetOffset_[ijet] : " << pseudojetTMP->Et() - jetOffset_[ijet]
                                 << '\n';
    LogDebug("PileUpSubtractor") << "Scale is : " << mScale << '\n';
    int cshist = pseudojetTMP->cluster_hist_index();
    pseudojetTMP->reset_momentum(pseudojetTMP->px() * mScale,
                                 pseudojetTMP->py() * mScale,
                                 pseudojetTMP->pz() * mScale,
                                 pseudojetTMP->e() * mScale);
    pseudojetTMP->set_cluster_hist_index(cshist);
  }
}

double PileUpSubtractor::getCone(double cone, double eta, double phi, double& et, double& pu) {
  pu = 0;

  for (vector<HcalDetId>::const_iterator im = allgeomid_.begin(); im != allgeomid_.end(); im++) {
    if (im->depth() != 1)
      continue;
    const GlobalPoint& point = geo_->getPosition((DetId)(*im));
    double dr = reco::deltaR(point.eta(), point.phi(), eta, phi);
    if (dr < cone) {
      pu += (*emean_.find(im->ieta())).second + (*esigma_.find(im->ieta())).second;
    }
  }

  return pu;
}

double PileUpSubtractor::getMeanAtTower(const reco::CandidatePtr& in) const {
  int it = ieta(in);
  return (*emean_.find(it)).second;
}

double PileUpSubtractor::getSigmaAtTower(const reco::CandidatePtr& in) const {
  int it = ieta(in);
  return (*esigma_.find(it)).second;
}

double PileUpSubtractor::getPileUpAtTower(const reco::CandidatePtr& in) const {
  int it = ieta(in);
  return (*emean_.find(it)).second + (*esigma_.find(it)).second;
}

int PileUpSubtractor::getN(const reco::CandidatePtr& in) const {
  int it = ieta(in);

  int n = (*(geomtowers_.find(it))).second - (*(ntowersWithJets_.find(it))).second;
  return n;
}

int PileUpSubtractor::getNwithJets(const reco::CandidatePtr& in) const {
  int it = ieta(in);
  int n = (*(ntowersWithJets_.find(it))).second;
  return n;
}

int PileUpSubtractor::ieta(const reco::CandidatePtr& in) const {
  int it = 0;
  const CaloTower* ctc = dynamic_cast<const CaloTower*>(in.get());
  if (ctc) {
    it = ctc->id().ieta();
  } else {
    throw cms::Exception("Invalid Constituent") << "CaloJet constituent is not of CaloTower type";
  }
  return it;
}

int PileUpSubtractor::iphi(const reco::CandidatePtr& in) const {
  int it = 0;
  const CaloTower* ctc = dynamic_cast<const CaloTower*>(in.get());
  if (ctc) {
    it = ctc->id().iphi();
  } else {
    throw cms::Exception("Invalid Constituent") << "CaloJet constituent is not of CaloTower type";
  }
  return it;
}

#include "FWCore/PluginManager/interface/PluginFactory.h"
EDM_REGISTER_PLUGINFACTORY(PileUpSubtractorFactory, "PileUpSubtractorFactory");