HybridClusterAlgo.cc

Go to the documentation of this file.

#include "RecoEcal/EgammaClusterAlgos/interface/HybridClusterAlgo.h"
#include "RecoCaloTools/Navigation/interface/EcalBarrelNavigator.h"
#include "DataFormats/GeometryVector/interface/GlobalPoint.h"
#include "Geometry/CaloGeometry/interface/CaloCellGeometry.h"
#include <iostream>
#include <map>
#include <vector>
#include <set>
#include "RecoEcal/EgammaCoreTools/interface/ClusterEtLess.h"

//The real constructor
HybridClusterAlgo::HybridClusterAlgo(double eb_str, 
                     int step, 
                     double ethres,
                     double eseed,
                     double ewing,
                     std::vector<int> v_chstatus,
                     const PositionCalc& posCalculator,
                     DebugLevel debugLevel,
                     bool dynamicEThres,
                     double eThresA,
                     double eThresB,
                     std::vector<int> severityToExclude,
                     double severityRecHitThreshold,
                     int severitySpikeId,
                     double severitySpikeThreshold,
                     bool excludeFromCluster
                     ) :
  
  eb_st(eb_str), phiSteps_(step), 
  eThres_(ethres), eThresA_(eThresA), eThresB_(eThresB),
  Eseed(eseed),  Ewing(ewing), 
  dynamicEThres_(dynamicEThres), debugLevel_(debugLevel),
  v_chstatus_(v_chstatus), v_severitylevel_(severityToExclude),severityRecHitThreshold_(severityRecHitThreshold), severitySpikeThreshold_(severitySpikeThreshold), excludeFromCluster_(excludeFromCluster)
  
  
{
  spId_ = EcalSeverityLevelAlgo::SpikeId(severitySpikeId);
  dynamicPhiRoad_ = false;
  if ( debugLevel_ == pDEBUG ) {
    //std::cout << "dynamicEThres: " << dynamicEThres_ 
    //          << " : A,B " << eThresA_ << ", " << eThresB_ << std::endl;
  }
  
  //if (dynamicPhiRoad_) phiRoadAlgo_ = new BremRecoveryPhiRoadAlgo(bremRecoveryPset);
  posCalculator_ = posCalculator;
  topo_ = new EcalBarrelHardcodedTopology();
  
  std::sort( v_chstatus_.begin(), v_chstatus_.end() );
  
  
}

// Return a vector of clusters from a collection of EcalRecHits:
void HybridClusterAlgo::makeClusters(const EcalRecHitCollection*recColl, 
                     const CaloSubdetectorGeometry*geometry,
                     reco::BasicClusterCollection &basicClusters,
                     bool regional,
                     const std::vector<EcalEtaPhiRegion>& regions,
                     const EcalChannelStatus*chStatus
                     )
{
  //clear vector of seeds
  seeds.clear();
  //clear flagged crystals
  excludedCrys_.clear();
  //clear map of supercluster/basiccluster association
  clustered_.clear();
  //clear set of used detids
  useddetids.clear();
  //clear vector of seed clusters
  seedClus_.clear();
  //Pass in a pointer to the collection.
  recHits_ = recColl;
  
  //
  //  SCShape_ = new SuperClusterShapeAlgo(recHits_, geometry);
  
  if ( debugLevel_ == pDEBUG ) {
    std::cout << "Cleared vectors, starting clusterization..." << std::endl;
    std::cout << "Purple monkey aardvark." << std::endl;
  }
  
  int nregions=0;
  if(regional) nregions=regions.size();
  
  if(!regional || nregions) {
    
    EcalRecHitCollection::const_iterator it;
    
    for (it = recHits_->begin(); it != recHits_->end(); it++){
      
      //Make the vector of seeds that we're going to use.
      //One of the few places position is used, needed for ET calculation.    
      const CaloCellGeometry *this_cell = (*geometry).getGeometry(it->id());
      GlobalPoint position = this_cell->getPosition();
      
      
      // Require that RecHit is within clustering region in case
      // of regional reconstruction
      bool withinRegion = false;
      if (regional) {
    std::vector<EcalEtaPhiRegion>::const_iterator region;
    for (region=regions.begin(); region!=regions.end(); region++) {
      if (region->inRegion(position)) {
        withinRegion =  true;
        break;
      }
    }
      }
      
      if (!regional || withinRegion) {

    //Must pass seed threshold
    float ET = it->energy() * sin(position.theta());

    if (ET > eb_st) {
      if (debugLevel_==pDEBUG) std::cout << "Seed crystal: " << std::endl;
      // avoid seeding for anomalous channels (recoFlag based)
      uint32_t rhFlag = (*it).recoFlag();
      if (debugLevel_==pDEBUG) std::cout << "rhFlag: " << rhFlag << std::endl;
      std::vector<int>::const_iterator vit = std::find( v_chstatus_.begin(), v_chstatus_.end(), rhFlag );
      if ( vit != v_chstatus_.end() ){
        if (excludeFromCluster_)
          excludedCrys_.insert(it->id());
        continue; // the recHit has to be excluded from seeding
      }
      int severityFlag =  EcalSeverityLevelAlgo::severityLevel( it->id(), 
                                  (*recHits_), 
                                  (*chStatus),
                                  severityRecHitThreshold_,
                                  spId_,
                                  severitySpikeThreshold_);
      std::vector<int>::const_iterator sit = std::find( v_severitylevel_.begin(), v_severitylevel_.end(), severityFlag);
      if (debugLevel_ == pDEBUG){
        std::cout << "found flag: " << severityFlag << std::endl;
      }
      
      
      if (sit!=v_severitylevel_.end()){ 
        if (excludeFromCluster_)
          excludedCrys_.insert(it->id());
        continue;
      }
      seeds.push_back(*it);
      if ( debugLevel_ == pDEBUG ){
        std::cout << "Seed ET: " << ET << std::endl;
        std::cout << "Seed E: " << it->energy() << std::endl;
      }
    }
      }
    }
    
  }
  
  
  //Yay sorting.
  if ( debugLevel_ == pDEBUG )
    std::cout << "Built vector of seeds, about to sort them...";
  
  //Needs three argument sort with seed comparison operator
  sort(seeds.begin(), seeds.end(), less_mag());
  
  if ( debugLevel_ == pDEBUG )
    std::cout << "done" << std::endl;
  
  //Now to do the work.
  if ( debugLevel_ ==pDEBUG ) 
    std::cout << "About to call mainSearch...";
  mainSearch(recColl,geometry);
  if ( debugLevel_ == pDEBUG ) 
    std::cout << "done" << std::endl;
  
  //Hand the basicclusters back to the producer.  It has to 
  //put them in the event.  Then we can make superclusters.
  std::map<int, reco::BasicClusterCollection>::iterator bic; 
  for (bic= clustered_.begin();bic!=clustered_.end();bic++){
    reco::BasicClusterCollection bl = bic->second;
    for (int j=0;j<int(bl.size());++j){
      basicClusters.push_back(bl[j]);
    }
  }
  
  //Yay more sorting.
  sort(basicClusters.rbegin(), basicClusters.rend(), ClusterEtLess() );
  //Done!
  if ( debugLevel_ == pDEBUG )
    std::cout << "returning to producer. " << std::endl;
}


void HybridClusterAlgo::mainSearch(const EcalRecHitCollection* hits, const CaloSubdetectorGeometry*geometry)
{

    if ( debugLevel_ ==pDEBUG ) {
        std::cout << "HybridClusterAlgo Algorithm - looking for clusters" << std::endl;
        std::cout << "Found the following clusters:" << std::endl;
    }

    // Loop over seeds:
    std::vector<EcalRecHit>::iterator it;
    int clustercounter=0;

    for (it = seeds.begin(); it != seeds.end(); it++){
        std::vector <reco::BasicCluster> thisseedClusters;
        DetId itID = it->id();

        // make sure the current seed has not been used/will not be used in the future:
        std::set<DetId>::iterator seed_in_rechits_it = useddetids.find(itID);

        if (seed_in_rechits_it != useddetids.end()) continue;
        //If this seed is already used, then don't use it again.

        // output some info on the hit:
        if ( debugLevel_ == pDEBUG ){
            std::cout << "*****************************************************" << std::endl;
            std::cout << "Seed of energy E = " << it->energy() << " @ " << EBDetId(itID) 
                << std::endl;
            std::cout << "*****************************************************" << std::endl;
        }

        //Make a navigator, and set it to the seed cell.
        EcalBarrelNavigator navigator(itID, topo_);

        //Now use the navigator to start building dominoes.

        //Walking positive in phi:
        std::vector <double> dominoEnergyPhiPlus;  //Here I will store the results of the domino sums
        std::vector <std::vector <EcalRecHit> > dominoCellsPhiPlus; //These are the actual EcalRecHit for dominos.

        //Walking negative in phi
        std::vector <double> dominoEnergyPhiMinus;  //Here I will store the results of the domino sums
        std::vector <std::vector <EcalRecHit> > dominoCellsPhiMinus; //These are the actual EcalRecHit for dominos.

        //The two sets together.
        std::vector <double> dominoEnergy;  //Here I will store the results of the domino sums
        std::vector <std::vector <EcalRecHit> > dominoCells; //These are the actual EcalRecHit for dominos.

        //First, the domino about the seed:
        std::vector <EcalRecHit> initialdomino;
        double e_init = makeDomino(navigator, initialdomino);
        if (e_init < Eseed) continue;

        if ( debugLevel_ == pDEBUG )
        {
            std::cout << "Made initial domino" << std::endl;
        }

        //
        // compute the phi road length
        double phiSteps;
        if (dynamicPhiRoad_ && e_init > 0)
        {
            double et5x5 = et25(navigator, hits, geometry);
            phiSteps = phiRoadAlgo_->barrelPhiRoad(et5x5);
            navigator.home();
        } else phiSteps = phiSteps_;

        //Positive phi steps.
        for (int i=0;i<phiSteps;++i){
            //remember, this always increments the current position of the navigator.
            DetId centerD = navigator.north();
            if (centerD.null())
                continue;
            if ( debugLevel_ == pDEBUG )
            {
                std::cout << "Step ++" << i << " @ " << EBDetId(centerD) << std::endl;
            }
            EcalBarrelNavigator dominoNav(centerD, topo_);

            //Go get the new domino.
            std::vector <EcalRecHit> dcells;
            double etemp = makeDomino(dominoNav, dcells);

            //save this information
            dominoEnergyPhiPlus.push_back(etemp);
            dominoCellsPhiPlus.push_back(dcells);
        }

        if ( debugLevel_ == pDEBUG )
            std::cout << "Got positive dominos" << std::endl;
        //return to initial position
        navigator.home();

        //Negative phi steps.
        for (int i=0;i<phiSteps;++i){
            //remember, this always decrements the current position of the navigator.
            DetId centerD = navigator.south();
            if (centerD.null())
                continue;

            if ( debugLevel_ == pDEBUG )
            {
                std::cout << "Step --" << i << " @ " << EBDetId(centerD) << std::endl;
            }
            EcalBarrelNavigator dominoNav(centerD, topo_);

            //Go get the new domino.
            std::vector <EcalRecHit> dcells;
            double etemp = makeDomino(dominoNav, dcells);

            //save this information
            dominoEnergyPhiMinus.push_back(etemp);
            dominoCellsPhiMinus.push_back(dcells);
        }

        if ( debugLevel_ == pDEBUG )
            std::cout << "Got negative dominos: " << std::endl;

        //Assemble this information:
        for (int i=int(dominoEnergyPhiMinus.size())-1;i >= 0;--i){
            dominoEnergy.push_back(dominoEnergyPhiMinus[i]);
            dominoCells.push_back(dominoCellsPhiMinus[i]);
        }
        dominoEnergy.push_back(e_init);
        dominoCells.push_back(initialdomino);
        for (int i=0;i<int(dominoEnergyPhiPlus.size());++i){
            dominoEnergy.push_back(dominoEnergyPhiPlus[i]);
            dominoCells.push_back(dominoCellsPhiPlus[i]);
        }

        //Ok, now I have all I need in order to go ahead and make clusters.
        if ( debugLevel_ == pDEBUG ){
            std::cout << "Dumping domino energies: " << std::endl;
            for (int i=0;i<int(dominoEnergy.size());++i){
                std::cout << "Domino: " << i << " E: " << dominoEnergy[i] << std::endl;
            }
        }


        //Identify the peaks in this set of dominos:
        //Peak==a domino whose energy is greater than the two adjacent dominos.
        //thus a peak in the local sense.
        std::vector <int> PeakIndex;
        for (int i=1;i<int(dominoEnergy.size())-1;++i){
            if (dominoEnergy[i] > dominoEnergy[i-1]
                    && dominoEnergy[i] >= dominoEnergy[i+1]
                    && dominoEnergy[i] > Eseed){
                PeakIndex.push_back(i);
            }
        }

        if ( debugLevel_ == pDEBUG )
            std::cout << "Found: " << PeakIndex.size() << " peaks." << std::endl;

        //Order these peaks by energy:
        for (int i=0;i<int(PeakIndex.size());++i){
            for (int j=0;j<int(PeakIndex.size())-1;++j){
                if (dominoEnergy[PeakIndex[j]] < dominoEnergy[PeakIndex[j+1]]){
                    int ihold = PeakIndex[j+1];
                    PeakIndex[j+1] = PeakIndex[j];
                    PeakIndex[j] = ihold;
                }
            }
        }

        std::vector<int> OwnerShip;
        std::vector<double> LumpEnergy;
        for (int i=0;i<int(dominoEnergy.size());++i) OwnerShip.push_back(-1);

        //Loop over peaks.  
        double eThres = eThres_;
        double e5x5 = 0.0;
        for (int i = 0; i < int(PeakIndex.size()); ++i)
        {

            int idxPeak = PeakIndex[i];
            OwnerShip[idxPeak] = i;
            double lump = dominoEnergy[idxPeak];

            // compute eThres for this peak
            // if set to dynamic (otherwise uncanged from
            // fixed setting
            if (dynamicEThres_) {

                //std::cout << "i : " << i << " idxPeak " << idxPeak << std::endl;
                //std::cout << "    the dominoEnergy.size() = " << dominoEnergy.size() << std::endl;
                // compute e5x5 for this seed crystal
                //std::cout << "idxPeak, phiSteps " << idxPeak << ", " << phiSteps << std::endl;
                e5x5 = lump;
                //std::cout << "lump " << e5x5 << std::endl;
                if ((idxPeak + 1) < (int)dominoEnergy.size()) e5x5 += dominoEnergy[idxPeak + 1];
                //std::cout << "+1 " << e5x5 << std::endl;
                if ((idxPeak + 2) < (int)dominoEnergy.size()) e5x5 += dominoEnergy[idxPeak + 2];
                //std::cout << "+2 " << e5x5 << std::endl;
                if ((idxPeak - 1) > 0) e5x5 += dominoEnergy[idxPeak - 1];
                //std::cout << "-1 " << e5x5 << std::endl;
                if ((idxPeak - 2) > 0) e5x5 += dominoEnergy[idxPeak - 2];
                //std::cout << "-2 " << e5x5 << std::endl;
                // compute eThres
                eThres = (eThresA_ * e5x5) + eThresB_;   
                //std::cout << eThres << std::endl;
                //std::cout << std::endl;
            }

            //Loop over adjacent dominos at higher phi
            for (int j=idxPeak+1;j<int(dominoEnergy.size());++j){
                if (OwnerShip[j]==-1 && 
                        dominoEnergy[j] > eThres
                        && dominoEnergy[j] <= dominoEnergy[j-1]){
                    OwnerShip[j]= i;
                    lump+=dominoEnergy[j];
                }
                else{
                    break;
                }
            }
            //loop over adjacent dominos at lower phi.  Sum up energy of lumps.
            for (int j=idxPeak-1;j>=0;--j){
                if (OwnerShip[j]==-1 && 
                        dominoEnergy[j] > eThres
                        && dominoEnergy[j] <= dominoEnergy[j+1]){
                    OwnerShip[j]= i;
                    lump+=dominoEnergy[j];
                }
                else{
                    break;
                }
            }
            LumpEnergy.push_back(lump);
        }

        //Make the basic clusters:
        for (int i=0;i<int(PeakIndex.size());++i){
            bool HasSeedCrystal = false;
            //One cluster for each peak.
            std::vector<EcalRecHit> recHits;
            std::vector< std::pair<DetId, float> > dets;
            int nhits=0;
            for (int j=0;j<int(dominoEnergy.size());++j){   
                if (OwnerShip[j] == i){
                    std::vector <EcalRecHit> temp = dominoCells[j];
                    for (int k=0;k<int(temp.size());++k){
                        dets.push_back( std::pair<DetId, float>(temp[k].id(), 1.) ); // by default energy fractions are 1
                        if (temp[k].id()==itID)
                            HasSeedCrystal = true;
                        recHits.push_back(temp[k]);
                        nhits++;
                    }
                }  
            }
            if ( debugLevel_ == pDEBUG ){
                std::cout << "Adding a cluster with: " << nhits << std::endl;
                std::cout << "total E: " << LumpEnergy[i] << std::endl;
                std::cout << "total dets: " << dets.size() << std::endl;
            }

            //Get Calorimeter position
            Point pos = posCalculator_.Calculate_Location(dets,hits,geometry);

            //double totChi2=0;
            //double totE=0;
            std::vector<std::pair<DetId, float> > usedHits;
            for (int blarg=0;blarg<int(recHits.size());++blarg){
                //totChi2 +=0;
                //totE+=recHits[blarg].energy();
                usedHits.push_back(std::make_pair<DetId, float>(recHits[blarg].id(), 1.0));
                useddetids.insert(recHits[blarg].id());
            }

            //if (totE>0)
            //totChi2/=totE;

            if (HasSeedCrystal) {
                // note that this "basiccluster" has the seed crystal of the hyrbid, so record it
                seedClus_.push_back(reco::BasicCluster(LumpEnergy[i], pos, 
                    reco::CaloID(reco::CaloID::DET_ECAL_BARREL), usedHits, 
                    reco::CaloCluster::hybrid, itID));
                // and also add to the vector of clusters that will be used in constructing
                // the supercluster
                                thisseedClusters.push_back(reco::BasicCluster(LumpEnergy[i], pos,                                                               reco::CaloID(reco::CaloID::DET_ECAL_BARREL), 
                                     usedHits, reco::CaloCluster::hybrid, itID));
            }
            else {
                // note that if this "basiccluster" is not the one that seeded the hybrid, 
                // the seed crystal is unset in this entry in the vector of clusters that will
                // be used in constructing the super cluster
                thisseedClusters.push_back(reco::BasicCluster(LumpEnergy[i], pos,                                                   reco::CaloID(reco::CaloID::DET_ECAL_BARREL), 
                     usedHits, reco::CaloCluster::hybrid));
            }
        }


        // Make association so that superclusters can be made later.
        // but only if some BasicClusters have been found...
        if (thisseedClusters.size() > 0) 
        {
            clustered_.insert(std::make_pair(clustercounter, thisseedClusters));
            clustercounter++;
        }
    }//Seed loop

}

reco::SuperClusterCollection HybridClusterAlgo::makeSuperClusters(const reco::CaloClusterPtrVector& clustersCollection)
{
    //Here's what we'll return.
    reco::SuperClusterCollection SCcoll;

    //Here's our map iterator that gives us the appropriate association.
    std::map<int, reco::BasicClusterCollection>::iterator mapit;
    for (mapit = clustered_.begin();mapit!=clustered_.end();mapit++){

        reco::CaloClusterPtrVector thissc;
        reco::CaloClusterPtr seed;//This is not really a seed, but I need to tell SuperCluster something.
        //So I choose the highest energy basiccluster in the SuperCluster.

        std::vector <reco::BasicCluster> thiscoll = mapit->second; //This is the set of BasicClusters in this
        //SuperCluster

        double ClusterE = 0; //Sum of cluster energies for supercluster.
        //Holders for position of this supercluster.
        double posX=0;
        double posY=0;
        double posZ=0;

        //Loop over this set of basic clusters, find their references, and add them to the
        //supercluster.  This could be somehow more efficient.

        for (int i=0;i<int(thiscoll.size());++i){
            reco::BasicCluster thisclus = thiscoll[i]; //The Cluster in question.
            for (int j=0;j<int(clustersCollection.size());++j){
                //Find the appropriate cluster from the list of references
                reco::BasicCluster cluster_p = *clustersCollection[j];
                if (thisclus== cluster_p){ //Comparison based on energy right now.
                    thissc.push_back(clustersCollection[j]);
                    bool isSeed = false;
                    for (int qu=0;qu<int(seedClus_.size());++qu){
                        if (cluster_p == seedClus_[qu])
                            isSeed = true;
                    }
                    if (isSeed) seed = clustersCollection[j];

                    ClusterE += cluster_p.energy();
                    posX += cluster_p.energy() * cluster_p.position().X();
                    posY += cluster_p.energy() * cluster_p.position().Y();
                    posZ += cluster_p.energy() * cluster_p.position().Z();

                }
            }//End loop over finding references.
        }//End loop over clusters.

        posX /= ClusterE;
        posY /= ClusterE;
        posZ /= ClusterE;

        /* //This part is moved to EgammaSCEnergyCorrectionAlgo
           double preshowerE = 0.;
           double phiWidth = 0.;
           double etaWidth = 0.;
        //Calculate phiWidth & etaWidth for SuperClusters
        reco::SuperCluster suCl(ClusterE, math::XYZPoint(posX, posY, posZ), seed, thissc, preshowerE, phiWidth, etaWidth);
        SCShape_->Calculate_Covariances(suCl);
        phiWidth = SCShape_->phiWidth();
        etaWidth = SCShape_->etaWidth();
        //Assign phiWidth & etaWidth to SuperCluster as data members
        suCl.setPhiWidth(phiWidth);
        suCl.setEtaWidth(etaWidth);
         */

        reco::SuperCluster suCl(ClusterE, math::XYZPoint(posX, posY, posZ), seed, thissc);
        SCcoll.push_back(suCl);

        if ( debugLevel_ == pDEBUG ){
            std::cout << "Super cluster sum: " << ClusterE << std::endl;
            std::cout << "Made supercluster with energy E: " << suCl.energy() << std::endl;
        }
    }//end loop over map
    sort(SCcoll.rbegin(), SCcoll.rend(), ClusterEtLess());
    return SCcoll;
}

double HybridClusterAlgo::makeDomino(EcalBarrelNavigator &navigator, std::vector <EcalRecHit> &cells)
{
    //At the beginning of this function, the navigator starts at the middle of the domino,
    //and that's where EcalBarrelNavigator::home() should send it.
    //Walk one crystal in eta to either side of the initial point.  Sum the three cell energies.
    //If the resultant energy is larger than Ewing, then go an additional cell to either side.
    //Returns:  Total domino energy.  Also, stores the cells used to create domino in the vector.
    cells.clear();
    double Etot = 0;

    //Ready?  Get the starting cell.
    DetId center = navigator.pos();
    EcalRecHitCollection::const_iterator center_it = recHits_->find(center);

    if (center_it!=recHits_->end()){
        EcalRecHit SeedHit = *center_it;
        if (useddetids.find(center) == useddetids.end() && excludedCrys_.find(center)==excludedCrys_.end()){ 
            Etot += SeedHit.energy();
            cells.push_back(SeedHit);
        }
    }
    //One step upwards in Ieta:
    DetId ieta1 = navigator.west();
    EcalRecHitCollection::const_iterator eta1_it = recHits_->find(ieta1);
    if (eta1_it !=recHits_->end()){
        EcalRecHit UpEta = *eta1_it;
        if (useddetids.find(ieta1) == useddetids.end() && excludedCrys_.find(ieta1)==excludedCrys_.end()){
            Etot+=UpEta.energy();
            cells.push_back(UpEta);
        }
    }

    //Go back to the middle.
    navigator.home();

    //One step downwards in Ieta:
    DetId ieta2 = navigator.east();
    EcalRecHitCollection::const_iterator eta2_it = recHits_->find(ieta2);
    if (eta2_it !=recHits_->end()){
        EcalRecHit DownEta = *eta2_it;
        if (useddetids.find(ieta2)==useddetids.end() && excludedCrys_.find(ieta2)==excludedCrys_.end()){
            Etot+=DownEta.energy();
            cells.push_back(DownEta);
        }
    }

    //Now check the energy.  If smaller than Ewing, then we're done.  If greater than Ewing, we have to
    //add two additional cells, the 'wings'
    if (Etot < Ewing) {
        navigator.home(); //Needed even here!!
        return Etot;  //Done!  Not adding 'wings'.
    }

    //Add the extra 'wing' cells.  Remember, we haven't sent the navigator home,
    //we're still on the DownEta cell.
    if (ieta2 != DetId(0)){
        DetId ieta3 = navigator.east(); //Take another step downward.
        EcalRecHitCollection::const_iterator eta3_it = recHits_->find(ieta3);
        if (eta3_it != recHits_->end()){
            EcalRecHit DownEta2 = *eta3_it;
            if (useddetids.find(ieta3)==useddetids.end() && excludedCrys_.find(ieta3)==excludedCrys_.end()){
                Etot+=DownEta2.energy();
                cells.push_back(DownEta2);
            }
        }
    }
    //Now send the navigator home.
    navigator.home();
    navigator.west(); //Now you're on eta1_it
    if (ieta1 != DetId(0)){
        DetId ieta4 = navigator.west(); //Take another step upward.
        EcalRecHitCollection::const_iterator eta4_it = recHits_->find(ieta4);
        if (eta4_it != recHits_->end()){
            EcalRecHit UpEta2 = *eta4_it;
            if (useddetids.find(ieta4) == useddetids.end() && excludedCrys_.find(ieta4)==excludedCrys_.end()){
                Etot+=UpEta2.energy();
                cells.push_back(UpEta2);
            }
        }
    }
    navigator.home();
    return Etot;
}

double HybridClusterAlgo::et25(EcalBarrelNavigator &navigator, 
        const EcalRecHitCollection *hits, 
        const CaloSubdetectorGeometry *geometry)
{

    DetId thisDet;
    std::vector< std::pair<DetId, float> > dets;
    dets.clear();
    EcalRecHitCollection::const_iterator hit;
    double energySum = 0.0;

    for (int dx = -2; dx < 3; ++dx)
    {
        for (int dy = -2; dy < 3; ++ dy)
        {
            //std::cout << "dx, dy " << dx << ", " << dy << std::endl;
            thisDet = navigator.offsetBy(dx, dy);
            navigator.home();

            if (thisDet != DetId(0))
            {
                hit = recHits_->find(thisDet);
                if (hit != recHits_->end()) 
                {
                    dets.push_back( std::pair<DetId, float>(thisDet, 1.) ); // by default hit energy fraction is set to 1
                    energySum += hit->energy();
                }
            }
        }
    }

    // convert it to ET
    //std::cout << "dets.size(), energySum: " << dets.size() << ", " << energySum << std::endl;
    Point pos = posCalculator_.Calculate_Location(dets, hits, geometry);
    double et = energySum/cosh(pos.eta());
    return et;

}