JetIDHelper.cc

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

#include "FWCore/MessageLogger/interface/MessageLogger.h"

#include "FWCore/Framework/interface/Frameworkfwd.h"
#include "FWCore/Framework/interface/EDProducer.h"
#include "FWCore/Framework/interface/Event.h"
#include "FWCore/Framework/interface/MakerMacros.h"
#include "FWCore/ParameterSet/interface/ParameterSet.h"
#include "FWCore/Utilities/interface/InputTag.h"


#include "DataFormats/METReco/interface/HcalCaloFlagLabels.h"
// JetIDHelper needs a much more detailed description that the one in HcalTopology, 
// so to be consistent, all needed constants are hardwired in JetIDHelper.cc itself
// #include "Geometry/CaloTopology/interface/HcalTopology.h"

#include "TMath.h"
#include <vector>
#include <numeric>
#include <iostream>

using namespace std;

// defining stuff useful only for this class (not needed in header)
namespace reco {

  namespace helper {

    // select2nd exists only in some std and boost implementations, so let's control our own fate
    // and it can't be a non-static member function.
    static double select2nd (std::map<int,double>::value_type const &pair) {return pair.second;}
    
    bool hasNonPositiveE( reco::helper::JetIDHelper::subtower x ) {
      return x.E <= 0;
    }
    
    bool subtower_has_greater_E( reco::helper::JetIDHelper::subtower i, 
                 reco::helper::JetIDHelper::subtower j ) { return i.E > j.E; }
    std::atomic<int> JetIDHelper::sanity_checks_left_{100};
  }
}

reco::helper::JetIDHelper::JetIDHelper( edm::ParameterSet const & pset, edm::ConsumesCollector&& iC )
{
  useRecHits_ = pset.getParameter<bool>("useRecHits");
  if( useRecHits_ ) {
    hbheRecHitsColl_ = pset.getParameter<edm::InputTag>("hbheRecHitsColl");
    hoRecHitsColl_   = pset.getParameter<edm::InputTag>("hoRecHitsColl");
    hfRecHitsColl_   = pset.getParameter<edm::InputTag>("hfRecHitsColl");
    ebRecHitsColl_   = pset.getParameter<edm::InputTag>("ebRecHitsColl");
    eeRecHitsColl_   = pset.getParameter<edm::InputTag>("eeRecHitsColl");   
  }
  initValues();

  input_HBHERecHits_token_ = iC.consumes<HBHERecHitCollection>(hbheRecHitsColl_); 
  input_HORecHits_token_ = iC.consumes<HORecHitCollection>(hoRecHitsColl_);   
  input_HFRecHits_token_ = iC.consumes<HFRecHitCollection>(hfRecHitsColl_);   
  input_EBRecHits_token_ = iC.consumes<EBRecHitCollection>(ebRecHitsColl_);   
  input_EERecHits_token_ = iC.consumes<EERecHitCollection>(eeRecHitsColl_);   


}
  
void reco::helper::JetIDHelper::initValues()
{
  fHPD_= -1.0;
  fRBX_= -1.0;
  n90Hits_ = -1;
  fSubDetector1_= -1.0;
  fSubDetector2_= -1.0;
  fSubDetector3_= -1.0;
  fSubDetector4_= -1.0;
  restrictedEMF_= -1.0;
  nHCALTowers_ = -1;
  nECALTowers_ = -1;
  approximatefHPD_ = -1.0;
  approximatefRBX_ = -1.0;
  hitsInN90_ = -1;
  fEB_ = fEE_ = fHB_ = fHE_ = fHO_ = fLong_ = fShort_ = -1.0;
  fLS_ = fHFOOT_ = -1.0;
}

void reco::helper::JetIDHelper::fillDescription(edm::ParameterSetDescription& iDesc)
{
  iDesc.ifValue( edm::ParameterDescription<bool>("useRecHits", true, true),
         true >> (edm::ParameterDescription<edm::InputTag>("hbheRecHitsColl", edm::InputTag(), true) and
              edm::ParameterDescription<edm::InputTag>("hoRecHitsColl", edm::InputTag(), true) and
              edm::ParameterDescription<edm::InputTag>("hfRecHitsColl", edm::InputTag(), true) and
              edm::ParameterDescription<edm::InputTag>("ebRecHitsColl", edm::InputTag(), true) and
              edm::ParameterDescription<edm::InputTag>("eeRecHitsColl", edm::InputTag(), true)
              ) 
                 )->setComment("If using RecHits to calculate the precise jet ID variables that need them, "
                   "their sources need to be specified");
}


void reco::helper::JetIDHelper::calculate( const edm::Event& event, const reco::CaloJet &jet, const int iDbg )
{
  initValues();

  // --------------------------------------------------
  // 1) jet ID variable derived from existing fractions
  // --------------------------------------------------

  double E_EM = TMath::Max( float(0.), jet.emEnergyInHF() )
              + TMath::Max( float(0.), jet.emEnergyInEB() )
              + TMath::Max( float(0.), jet.emEnergyInEE() );
  double E_Had = TMath::Max( float(0.), jet.hadEnergyInHB() )
               + TMath::Max( float(0.), jet.hadEnergyInHE() )
               + TMath::Max( float(0.), jet.hadEnergyInHO() )
               + TMath::Max( float(0.), jet.hadEnergyInHF() );
  if( E_Had + E_EM > 0 ) restrictedEMF_ = E_EM / ( E_EM + E_Had );
  if( iDbg > 1 ) cout<<"jet pT: "<<jet.pt()<<", eT: "<<jet.et()<<", E: "
             <<jet.energy()<<" rEMF: "<<restrictedEMF_<<endl;

  // ------------------------
  // 2) tower based variables
  // ------------------------
  vector<subtower> subtowers, Ecal_subtowers, Hcal_subtowers, HO_subtowers;
  vector<double> HPD_energies, RBX_energies;

  classifyJetTowers( event, jet, 
             subtowers, Ecal_subtowers, Hcal_subtowers, HO_subtowers, 
             HPD_energies, RBX_energies, iDbg );
  if( iDbg > 1 ) {
    cout<<"E:";
    for (unsigned int i=0; i<subtowers.size(); ++i) cout<<" "<<subtowers[i].E<<","<<subtowers[i].Nhit;
    cout<<"\nECal_E:";
    for (unsigned int i=0; i<Ecal_subtowers.size(); ++i) cout<<" "<<Ecal_subtowers[i].E<<","<<Ecal_subtowers[i].Nhit;
    cout<<"\nHCal_E:";
    for (unsigned int i=0; i<Hcal_subtowers.size(); ++i) cout<<" "<<Hcal_subtowers[i].E<<","<<Hcal_subtowers[i].Nhit;
    cout<<"\nHO_E:";
    for (unsigned int i=0; i<HO_subtowers.size(); ++i) cout<<" "<<HO_subtowers[i].E<<","<<HO_subtowers[i].Nhit;
    cout<<"\nHPD_E:";
    for (unsigned int i=0; i<HPD_energies.size(); ++i) cout<<" "<<HPD_energies[i];
    cout<<"\nRBX_E:";
    for (unsigned int i=0; i<RBX_energies.size(); ++i) cout<<" "<<RBX_energies[i];
    cout<<endl;
  }

  // counts
  hitsInN90_ = hitsInNCarrying( 0.9, subtowers );
  nHCALTowers_ = Hcal_subtowers.size();
  vector<subtower>::const_iterator it;
  it = find_if( Ecal_subtowers.begin(), Ecal_subtowers.end(), hasNonPositiveE );
  nECALTowers_ = it - Ecal_subtowers.begin(); // ignores negative energies from HF!

  // energy fractions
  double max_HPD_energy = 0., max_RBX_energy = 0.;
  std::vector<double>::const_iterator it_max_HPD_energy = std::max_element( HPD_energies.begin(), HPD_energies.end() );
  std::vector<double>::const_iterator it_max_RBX_energy = std::max_element( RBX_energies.begin(), RBX_energies.end() );
  if ( it_max_HPD_energy != HPD_energies.end() ) {
    max_HPD_energy = *it_max_HPD_energy;
  }
  if ( it_max_RBX_energy != RBX_energies.end() ) {
    max_RBX_energy = *it_max_RBX_energy;
  }
  if( jet.energy() > 0 ) {
    if( HPD_energies.size() > 0 ) approximatefHPD_ = max_HPD_energy / jet.energy();
    if( RBX_energies.size() > 0 ) approximatefRBX_ = max_HPD_energy / jet.energy();
  }

  // -----------------------
  // 3) cell based variables
  // -----------------------
  if( useRecHits_ ) {
    vector<double> energies, subdet_energies, Ecal_energies, Hcal_energies, HO_energies;
    double LS_bad_energy, HF_OOT_energy;
    classifyJetComponents( event, jet, 
               energies, subdet_energies, Ecal_energies, Hcal_energies, HO_energies, 
               HPD_energies, RBX_energies, LS_bad_energy, HF_OOT_energy, iDbg );

    // counts
    n90Hits_ = nCarrying( 0.9, energies );

    // energy fractions
    if( jet.energy() > 0 ) {
      if( HPD_energies.size() > 0 ) fHPD_ = max_HPD_energy / jet.energy();
      if( RBX_energies.size() > 0 ) fRBX_ = max_RBX_energy / jet.energy();
      if( subdet_energies.size() > 0 ) fSubDetector1_ = subdet_energies.at( 0 ) / jet.energy();
      if( subdet_energies.size() > 1 ) fSubDetector2_ = subdet_energies.at( 1 ) / jet.energy();
      if( subdet_energies.size() > 2 ) fSubDetector3_ = subdet_energies.at( 2 ) / jet.energy();
      if( subdet_energies.size() > 3 ) fSubDetector4_ = subdet_energies.at( 3 ) / jet.energy();
      fLS_ = LS_bad_energy / jet.energy();
      fHFOOT_ = HF_OOT_energy / jet.energy();

      if( iDbg > 0 && sanity_checks_left_.load(std::memory_order_acquire) > 0 ) {
    --sanity_checks_left_;
    double EH_sum = accumulate( Ecal_energies.begin(), Ecal_energies.end(), 0. );
    EH_sum = accumulate( Hcal_energies.begin(), Hcal_energies.end(), EH_sum );
    double EHO_sum = accumulate( HO_energies.begin(), HO_energies.end(), EH_sum );
    if( jet.energy() > 0.001 && abs( EH_sum/jet.energy() - 1 ) > 0.01 && abs( EHO_sum/jet.energy() - 1 ) > 0.01 )
      edm::LogWarning("BadInput")<<"Jet energy ("<<jet.energy()
                     <<") does not match the total energy in the recHits ("<<EHO_sum
                     <<", or without HO: "<<EH_sum<<") . Are these the right recHits? "
                     <<"Were jet energy corrections mistakenly applied before jet ID? A bug?";
    if( iDbg > 1 ) cout<<"Sanity check - E: "<<jet.energy()<<" =? EH_sum: "<<EH_sum<<" / EHO_sum: "<<EHO_sum<<endl;
      }
    }

    if( iDbg > 1 ) {
      cout<<"DBG - fHPD: "<<fHPD_<<", fRBX: "<<fRBX_<<", nh90: "<<n90Hits_<<", fLS: "<<fLS_<<", fHFOOT: "<<fHFOOT_<<endl;
      cout<<"    -~fHPD: "<<approximatefHPD_<<", ~fRBX: "<<approximatefRBX_
      <<", hits in n90: "<<hitsInN90_<<endl;
      cout<<"    - nHCALTowers: "<<nHCALTowers_<<", nECALTowers: "<<nECALTowers_
      <<"; subdet fractions: "<<fSubDetector1_<<", "<<fSubDetector2_<<", "<<fSubDetector3_<<", "<<fSubDetector4_<<endl;
    }
  }
}


unsigned int reco::helper::JetIDHelper::nCarrying( double fraction, const std::vector< double >& descending_energies )
{
  double totalE = 0;
  for( unsigned int i = 0; i < descending_energies.size(); ++i ) totalE += descending_energies[ i ];

  double runningE = 0;
  unsigned int NC = descending_energies.size();
  
  // slightly odd loop structure avoids round-off problems when runningE never catches up with totalE
  for( unsigned int i = descending_energies.size(); i > 0; --i ) {
    runningE += descending_energies[ i-1 ];
    if (runningE < ( 1-fraction ) * totalE) NC = i-1;
  }
  return NC;
}


unsigned int reco::helper::JetIDHelper::hitsInNCarrying( double fraction, const std::vector< subtower >& descending_towers )
{
  double totalE = 0;
  for( unsigned int i = 0; i < descending_towers.size(); ++i ) totalE += descending_towers[ i ].E;

  double runningE = 0;
  unsigned int NH = 0;
  
  // slightly odd loop structure avoids round-off problems when runningE never catches up with totalE
  for( unsigned int i = descending_towers.size(); i > 0; --i ) {
    runningE += descending_towers[ i-1 ].E;
    if (runningE >= ( 1-fraction ) * totalE) NH += descending_towers[ i-1 ].Nhit;
  }
  return NH;
}

void reco::helper::JetIDHelper::classifyJetComponents( const edm::Event& event, const reco::CaloJet &jet, 
                               vector< double > &energies,      
                               vector< double > &subdet_energies,      
                               vector< double > &Ecal_energies, 
                               vector< double > &Hcal_energies, 
                               vector< double > &HO_energies,
                               vector< double > &HPD_energies,  
                               vector< double > &RBX_energies,
                               double& LS_bad_energy, double& HF_OOT_energy, const int iDbg )
{
  energies.clear(); subdet_energies.clear(); Ecal_energies.clear(); Hcal_energies.clear(); HO_energies.clear();
  HPD_energies.clear(); RBX_energies.clear();
  LS_bad_energy = HF_OOT_energy = 0.;
  
  std::map< int, double > HPD_energy_map, RBX_energy_map;
  vector< double > EB_energies, EE_energies, HB_energies, HE_energies, short_energies, long_energies;
  edm::Handle<HBHERecHitCollection> HBHERecHits;
  edm::Handle<HORecHitCollection> HORecHits;
  edm::Handle<HFRecHitCollection> HFRecHits;
  edm::Handle<EBRecHitCollection> EBRecHits;
  edm::Handle<EERecHitCollection> EERecHits;
  // the jet only contains DetIds, so first read recHit collection
  event.getByToken(input_HBHERecHits_token_, HBHERecHits );
  event.getByToken(input_HORecHits_token_, HORecHits );
  event.getByToken(input_HFRecHits_token_, HFRecHits );
  event.getByToken(input_EBRecHits_token_, EBRecHits );
  event.getByToken(input_EERecHits_token_, EERecHits );
  if( iDbg > 2 ) cout<<"# of rechits found - HBHE: "<<HBHERecHits->size()
             <<", HO: "<<HORecHits->size()<<", HF: "<<HFRecHits->size()
             <<", EB: "<<EBRecHits->size()<<", EE: "<<EERecHits->size()<<endl;

  vector< CaloTowerPtr > towers = jet.getCaloConstituents ();
  int nTowers = towers.size();
  if( iDbg > 9 ) cout<<"In classifyJetComponents. # of towers found: "<<nTowers<<endl;

  for( int iTower = 0; iTower <nTowers ; iTower++ ) {

    CaloTowerPtr& tower = towers[iTower];

    int nCells = tower->constituentsSize();
    if( iDbg ) cout<<"tower #"<<iTower<<" has "<<nCells<<" cells. "
           <<"It's at iEta: "<<tower->ieta()<<", iPhi: "<<tower->iphi()<<endl;

    const vector< DetId >& cellIDs = tower->constituents();  // cell == recHit
  
    for( int iCell = 0; iCell < nCells; ++iCell ) {
      DetId::Detector detNum = cellIDs[iCell].det();
      if( detNum == DetId::Hcal ) {
    HcalDetId HcalID = cellIDs[ iCell ];
    HcalSubdetector HcalNum = HcalID.subdet();
    double hitE = 0;
    if( HcalNum == HcalOuter ) {
      HORecHitCollection::const_iterator theRecHit=HORecHits->find(HcalID);
      if (theRecHit == HORecHits->end()) {
        edm::LogWarning("UnexpectedEventContents")<<"Can't find the HO recHit with ID: "<<HcalID;
        continue;
      }
      hitE = theRecHit->energy();
      HO_energies.push_back( hitE );
        
    } else if( HcalNum == HcalForward ) {
      
      HFRecHitCollection::const_iterator theRecHit=HFRecHits->find( HcalID );       
      if( theRecHit == HFRecHits->end() ) {
        edm::LogWarning("UnexpectedEventContents")<<"Can't find the HF recHit with ID: "<<HcalID;
        continue;
      }
      hitE = theRecHit->energy();
      if( iDbg>4 ) cout 
             << "hit #"<<iCell<<" is  HF , E: "<<hitE<<" iEta: "<<theRecHit->id().ieta()
             <<", depth: "<<theRecHit->id().depth()<<", iPhi: "
             <<theRecHit->id().iphi();
      
      if( HcalID.depth() == 1 ) 
        long_energies.push_back( hitE );
      else
        short_energies.push_back( hitE );
      
      uint32_t flags = theRecHit->flags();
      if( flags & (1<<HcalCaloFlagLabels::HFLongShort) ) LS_bad_energy += hitE;
      if( flags & ( (1<<HcalCaloFlagLabels::HFDigiTime) | 
            (3<<HcalCaloFlagLabels::HFTimingTrustBits) | 
            (1<<HcalCaloFlagLabels::TimingSubtractedBit) |
            (1<<HcalCaloFlagLabels::TimingAddedBit) |
            (1<<HcalCaloFlagLabels::TimingErrorBit) ) ) HF_OOT_energy += hitE;
      if( iDbg>4 && flags ) cout<<"flags: "<<flags
                    <<" -> LS_bad_energy: "<<LS_bad_energy<<", HF_OOT_energy: "<<HF_OOT_energy<<endl; 

    } else { // HBHE
      
      HBHERecHitCollection::const_iterator theRecHit = HBHERecHits->find( HcalID );     
      if( theRecHit == HBHERecHits->end() ) {
        edm::LogWarning("UnexpectedEventContents")<<"Can't find the HBHE recHit with ID: "<<HcalID; 
        continue;
      }
      hitE = theRecHit->energy();
      int iEta = theRecHit->id().ieta();
      int depth = theRecHit->id().depth();
      Region region = HBHE_region( iEta, depth );
      int hitIPhi = theRecHit->id().iphi();
      if( iDbg>3 ) cout<<"hit #"<<iCell<<" is HBHE, E: "<<hitE<<" iEta: "<<iEta
               <<", depth: "<<depth<<", iPhi: "<<theRecHit->id().iphi()
               <<" -> "<<region;
      int absIEta = TMath::Abs( theRecHit->id().ieta() );
      if( depth == 3 && (absIEta == 28 || absIEta == 29) ) {
        hitE /= 2; // Depth 3 at the HE forward edge is split over tower 28 & 29, and jet reco. assigns half each
      }
      int iHPD = 100 * region;
      int iRBX = 100 * region + ((hitIPhi + 1) % 72) / 4; // 71,72,1,2 are in the same RBX module
      
      if( std::abs( iEta ) >= 21 ) {
        if( (0x1 & hitIPhi) == 0 ) {
          edm::LogError("CodeAssumptionsViolated")<<"Bug?! Jet ID code assumes no even iPhi recHits at HE edges";
          return;
        }
        bool oddnessIEta = HBHE_oddness( iEta, depth );
        bool upperIPhi = (( hitIPhi%4 ) == 1 || ( hitIPhi%4 ) == 2); // the upper iPhi indices in the HE wedge
        // remap the iPhi so it fits the one in the inner HE regions, change in needed in two cases:
        // 1) in the upper iPhis of the module, the even iEtas belong to the higher iPhi
        // 2) in the loewr iPhis of the module, the odd  iEtas belong to the higher iPhi
        if( upperIPhi != oddnessIEta ) ++hitIPhi; 
        // note that hitIPhi could not be 72 before, so it's still in the legal range [1,72]
      }
      iHPD += hitIPhi;
      
      // book the energies
      HPD_energy_map[ iHPD ] += hitE;
      RBX_energy_map[ iRBX ] += hitE;
      if( iDbg > 5 ) cout<<" --> H["<<iHPD<<"]="<<HPD_energy_map[iHPD]
                 <<", R["<<iRBX<<"]="<<RBX_energy_map[iRBX];
      if( iDbg > 1 ) cout<<endl;
      
      if( region == HBneg || region == HBpos )
        HB_energies.push_back( hitE );
      else
        HE_energies.push_back( hitE );
      
    } // if HBHE
    if( hitE == 0 ) edm::LogWarning("UnexpectedEventContents")<<"HCal hitE==0? (or unknown subdetector?)";
    
      } // if HCAL 
    
      else if (detNum == DetId::Ecal) {
    
    int EcalNum =  cellIDs[iCell].subdetId();
    double hitE = 0;
    if( EcalNum == 1 ){
      EBDetId EcalID = cellIDs[iCell];
      EBRecHitCollection::const_iterator theRecHit=EBRecHits->find(EcalID);
      if( theRecHit == EBRecHits->end() ) {edm::LogWarning("UnexpectedEventContents")
          <<"Can't find the EB recHit with ID: "<<EcalID; continue;}
      hitE = theRecHit->energy();
      EB_energies.push_back( hitE );
    } else if(  EcalNum == 2 ){
      EEDetId EcalID = cellIDs[iCell];
      EERecHitCollection::const_iterator theRecHit=EERecHits->find(EcalID);
      if( theRecHit == EERecHits->end() ) {edm::LogWarning("UnexpectedEventContents")
          <<"Can't find the EE recHit with ID: "<<EcalID; continue;}
      hitE = theRecHit->energy();
      EE_energies.push_back( hitE );
    }
    if( hitE == 0 ) edm::LogWarning("UnexpectedEventContents")<<"ECal hitE==0? (or unknown subdetector?)";
    if( iDbg > 6 ) cout<<"EcalNum: "<<EcalNum<<" hitE: "<<hitE<<endl;
      } // 
    } // loop on cells
  } // loop on towers

  /* Disabling check until HO is accounted for in EMF. Check was used in CMSSW_2, where HE was excluded.
  double expHcalE = jet.energy() * (1-jet.emEnergyFraction());
  if( totHcalE + expHcalE > 0 && 
      TMath::Abs( totHcalE - expHcalE ) > 0.01 && 
      ( totHcalE - expHcalE ) / ( totHcalE + expHcalE ) > 0.0001 ) {
    edm::LogWarning("CodeAssumptionsViolated")<<"failed to account for all Hcal energies"
                          <<totHcalE<<"!="<<expHcalE;
                          } */   
  // concatenate Hcal and Ecal lists
  Hcal_energies.insert( Hcal_energies.end(), HB_energies.begin(), HB_energies.end() );
  Hcal_energies.insert( Hcal_energies.end(), HE_energies.begin(), HE_energies.end() );
  Hcal_energies.insert( Hcal_energies.end(), short_energies.begin(), short_energies.end() );
  Hcal_energies.insert( Hcal_energies.end(), long_energies.begin(), long_energies.end() );
  Ecal_energies.insert( Ecal_energies.end(), EB_energies.begin(), EB_energies.end() );
  Ecal_energies.insert( Ecal_energies.end(), EE_energies.begin(), EE_energies.end() );

  // sort the energies
  // std::sort( Hcal_energies.begin(), Hcal_energies.end(), greater<double>() );
  // std::sort( Ecal_energies.begin(), Ecal_energies.end(), greater<double>() );

  // put the energy sums (the 2nd entry in each pair of the maps) into the output vectors and sort them
  std::transform( HPD_energy_map.begin(), HPD_energy_map.end(), 
          std::inserter (HPD_energies, HPD_energies.end()), select2nd ); 
  //          std::select2nd<std::map<int,double>::value_type>());
  // std::sort( HPD_energies.begin(), HPD_energies.end(), greater<double>() );
  std::transform( RBX_energy_map.begin(), RBX_energy_map.end(), 
          std::inserter (RBX_energies, RBX_energies.end()), select2nd );
  //          std::select2nd<std::map<int,double>::value_type>());
  // std::sort( RBX_energies.begin(), RBX_energies.end(), greater<double>() );

  energies.insert( energies.end(), Hcal_energies.begin(), Hcal_energies.end() );
  energies.insert( energies.end(), Ecal_energies.begin(), Ecal_energies.end() );
  energies.insert( energies.end(), HO_energies.begin(), HO_energies.end() );
  std::sort( energies.begin(), energies.end(), greater<double>() );

  // prepare sub detector energies, then turn them into fractions
  fEB_ = std::accumulate( EB_energies.begin(), EB_energies.end(), 0. );
  fEE_ = std::accumulate( EE_energies.begin(), EE_energies.end(), 0. );
  fHB_ = std::accumulate( HB_energies.begin(), HB_energies.end(), 0. );
  fHE_ = std::accumulate( HE_energies.begin(), HE_energies.end(), 0. );
  fHO_ = std::accumulate( HO_energies.begin(), HO_energies.end(), 0. );
  fShort_ = std::accumulate( short_energies.begin(), short_energies.end(), 0. );
  fLong_ = std::accumulate( long_energies.begin(), long_energies.end(), 0. );
  subdet_energies.push_back( fEB_ );
  subdet_energies.push_back( fEE_ );
  subdet_energies.push_back( fHB_ );
  subdet_energies.push_back( fHE_ );
  subdet_energies.push_back( fHO_ );
  subdet_energies.push_back( fShort_ );
  subdet_energies.push_back( fLong_ );
  std::sort( subdet_energies.begin(), subdet_energies.end(), greater<double>() );
  if( jet.energy() > 0 ) {
    fEB_ /= jet.energy();
    fEE_ /= jet.energy();
    fHB_ /= jet.energy();
    fHE_ /= jet.energy();
    fHO_ /= jet.energy();
    fShort_ /= jet.energy();
    fLong_ /= jet.energy();
  } else {
    if( fEB_ > 0 || fEE_ > 0 || fHB_ > 0 || fHE_ > 0 || fHO_ > 0 || fShort_ > 0 || fLong_ > 0 )
      edm::LogError("UnexpectedEventContents")<<"Jet ID Helper found energy in subdetectors and jet E <= 0";
  }      
}

void reco::helper::JetIDHelper::classifyJetTowers( const edm::Event& event, const reco::CaloJet &jet, 
                           vector< subtower > &subtowers,      
                           vector< subtower > &Ecal_subtowers, 
                           vector< subtower > &Hcal_subtowers, 
                           vector< subtower > &HO_subtowers,
                           vector< double > &HPD_energies,  
                           vector< double > &RBX_energies,
                           const int iDbg )
{
  subtowers.clear(); Ecal_subtowers.clear(); Hcal_subtowers.clear(); HO_subtowers.clear();
  HPD_energies.clear(); RBX_energies.clear();

  std::map< int, double > HPD_energy_map, RBX_energy_map;

  vector< CaloTowerPtr > towers = jet.getCaloConstituents ();
  int nTowers = towers.size();
  if( iDbg > 9 ) cout<<"classifyJetTowers started. # of towers found: "<<nTowers<<endl;

  for( int iTower = 0; iTower <nTowers ; iTower++ ) {

    CaloTowerPtr& tower = towers[iTower];

    int nEM = 0, nHad = 0, nHO = 0;
    const vector< DetId >& cellIDs = tower->constituents();  // cell == recHit
    int nCells = cellIDs.size();
    if( iDbg ) cout<<"tower #"<<iTower<<" has "<<nCells<<" cells. "
           <<"It's at iEta: "<<tower->ieta()<<", iPhi: "<<tower->iphi()<<endl;
  
    for( int iCell = 0; iCell < nCells; ++iCell ) {
      DetId::Detector detNum = cellIDs[iCell].det();
      if( detNum == DetId::Hcal ) {
    HcalDetId HcalID = cellIDs[ iCell ];
    HcalSubdetector HcalNum = HcalID.subdet();
    if( HcalNum == HcalOuter ) {
      ++nHO;
    } else {
      ++nHad;
    }
      } else if (detNum == DetId::Ecal) {
    ++nEM;
      }
    }

    double E_em = tower->emEnergy();
    if( E_em != 0 ) Ecal_subtowers.push_back( subtower( E_em, nEM ) );
      
    double E_HO = tower->outerEnergy();
    if( E_HO != 0 ) HO_subtowers.push_back( subtower( E_HO, nHO ) );
      
    double E_had = tower->hadEnergy();
    if( E_had != 0 ) {
      Hcal_subtowers.push_back( subtower( E_had, nHad ) );
      // totHcalE += E_had;
      
      int iEta = tower->ieta();
      Region reg = region( iEta );
      int iPhi = tower->iphi();
      if( iDbg>3 ) cout<<"tower has E_had: "<<E_had<<" iEta: "<<iEta
               <<", iPhi: "<<iPhi<<" -> "<<reg;
      
      if( reg == HEneg || reg == HBneg || reg == HBpos || reg == HEpos ) {
    int oddnessIEta = HBHE_oddness( iEta );
    if( oddnessIEta < 0 ) break; // can't assign this tower to a single readout component
    
    int iHPD = 100 * reg;
    int iRBX = 100 * reg + ((iPhi + 1) % 72) / 4; // 71,72,1,2 are in the same RBX module
    
    if(( reg == HEneg || reg == HEpos ) && std::abs( iEta ) >= 21 ) { // at low-granularity edge of HE
      if( (0x1 & iPhi) == 0 ) {
        edm::LogError("CodeAssumptionsViolated")<<
          "Bug?! Jet ID code assumes no even iPhi recHits at HE edges";
        return;
      }
      bool boolOddnessIEta = oddnessIEta;
      bool upperIPhi = (( iPhi%4 ) == 1 || ( iPhi%4 ) == 2); // the upper iPhi indices in the HE wedge
      // remap the iPhi so it fits the one in the inner HE regions, change in needed in two cases:
      // 1) in the upper iPhis of the module, the even IEtas belong to the higher iPhi
      // 2) in the loewr iPhis of the module, the odd  IEtas belong to the higher iPhi
      if( upperIPhi != boolOddnessIEta ) ++iPhi; 
      // note that iPhi could not be 72 before, so it's still in the legal range [1,72]
    } // if at low-granularity edge of HE
    iHPD += iPhi;
    
    // book the energies
    HPD_energy_map[ iHPD ] += E_had;
    RBX_energy_map[ iRBX ] += E_had;
    if( iDbg > 5 ) cout<<" --> H["<<iHPD<<"]="<<HPD_energy_map[iHPD]
               <<", R["<<iRBX<<"]="<<RBX_energy_map[iRBX];
      } // HBHE
    } // E_had > 0
  } // loop on towers

  // sort the subtowers
  // std::sort( Hcal_subtowers.begin(), Hcal_subtowers.end(), subtower_has_greater_E );
  // std::sort( Ecal_subtowers.begin(), Ecal_subtowers.end(), subtower_has_greater_E );

  // put the energy sums (the 2nd entry in each pair of the maps) into the output vectors and sort them
  std::transform( HPD_energy_map.begin(), HPD_energy_map.end(), 
          std::inserter (HPD_energies, HPD_energies.end()), select2nd ); 
  //          std::select2nd<std::map<int,double>::value_type>());
  // std::sort( HPD_energies.begin(), HPD_energies.end(), greater<double>() );
  std::transform( RBX_energy_map.begin(), RBX_energy_map.end(), 
          std::inserter (RBX_energies, RBX_energies.end()), select2nd );
  //          std::select2nd<std::map<int,double>::value_type>());
  // std::sort( RBX_energies.begin(), RBX_energies.end(), greater<double>() );

  subtowers.insert( subtowers.end(), Hcal_subtowers.begin(), Hcal_subtowers.end() );
  subtowers.insert( subtowers.end(), Ecal_subtowers.begin(), Ecal_subtowers.end() );
  subtowers.insert( subtowers.end(), HO_subtowers.begin(), HO_subtowers.end() );
  std::sort( subtowers.begin(), subtowers.end(), subtower_has_greater_E );
}

// ---------------------------------------------------------------------------------------------------------
// private helper functions to figure out detector & readout geometry as needed

int reco::helper::JetIDHelper::HBHE_oddness( int iEta, int depth )
{
 int ae = TMath::Abs( iEta );
 if( ae == 29 && depth == 1 ) ae += 1; // observed that: hits are at depths 1 & 2; 1 goes with the even pattern
 return ae & 0x1;
}

reco::helper::JetIDHelper::Region reco::helper::JetIDHelper::HBHE_region( int iEta, int depth )
{
  // no error checking for HO indices (depth 2 & |ieta|<=14 or depth 3 & |ieta|=15)
  if( iEta <= -17 || ( depth == 3 && iEta == -16 ) ) return HEneg;
  if( iEta >=  17 || ( depth == 3 && iEta ==  16 ) ) return HEpos;
  if( iEta < 0 ) return HBneg;
  return HBpos;
}

int reco::helper::JetIDHelper::HBHE_oddness( int iEta )
{
 int ae = TMath::Abs( iEta );
 if( ae == 29 ) return -1; // can't figure it out without RecHits
 return ae & 0x1;
}

reco::helper::JetIDHelper::Region reco::helper::JetIDHelper::region( int iEta )
{
  if( iEta == 16 || iEta == -16 ) return unknown_region; // both HB and HE cells belong to these towers
  if( iEta == 29 || iEta == -29 ) return unknown_region; // both HE and HF cells belong to these towers
  if( iEta <= -30 ) return HFneg;
  if( iEta >=  30 ) return HFpos;
  if( iEta <= -17 ) return HEneg;
  if( iEta >=  17 ) return HEpos;
  if( iEta < 0 ) return HBneg;
  return HBpos;
}