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/data/refman/pasoursint/CMSSW_5_3_0/src/RecoJets/JetAlgorithms/src/FixedGridEnergyDensity.cc

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00001 #include "RecoJets/JetAlgorithms/interface/FixedGridEnergyDensity.h"
00002 
00003 #include "DataFormats/ParticleFlowCandidate/interface/PFCandidate.h"
00004 #include "DataFormats/Math/interface/deltaPhi.h"
00005 #include "TMath.h"
00006 
00007 using namespace reco;
00008 using namespace edm;
00009 using namespace std;
00010 
00011 float FixedGridEnergyDensity::fixedGridRho(EtaRegion etaRegion){
00012   //define the phi bins
00013   vector<float> phibins;
00014   for (int i=0;i<10;i++) phibins.push_back(-TMath::Pi()+(2*i+1)*TMath::TwoPi()/20.);
00015   //define the eta bins
00016   vector<float> etabins;
00017   if (etaRegion==Central) {
00018     for (int i=0;i<8;++i) etabins.push_back(-2.1+0.6*i);
00019   } else if (etaRegion==Forward) {
00020      for (int i=0;i<10;++i) {
00021        if (i<5) etabins.push_back(-5.1+0.6*i);
00022        else etabins.push_back(2.7+0.6*(i-5));
00023      }
00024   } else if (etaRegion==All) {
00025      for (int i=0;i<18;++i) etabins.push_back(-5.1+0.6*i);
00026   }
00027   return fixedGridRho(etabins,phibins);
00028 }
00029 
00030 
00031 float FixedGridEnergyDensity::fixedGridRho(std::vector<float>& etabins,std::vector<float>& phibins) {
00032      float etadist = etabins[1]-etabins[0];
00033      float phidist = phibins[1]-phibins[0];
00034      float etahalfdist = (etabins[1]-etabins[0])/2.;
00035      float phihalfdist = (phibins[1]-phibins[0])/2.;
00036      vector<float> sumPFNallSMDQ;
00037      sumPFNallSMDQ.reserve(etabins.size()*phibins.size());
00038      for (unsigned int ieta=0;ieta<etabins.size();++ieta) {
00039        for (unsigned int iphi=0;iphi<phibins.size();++iphi) {
00040          float pfniso_ieta_iphi = 0;
00041          for(PFCandidateCollection::const_iterator pf_it = pfCandidates->begin(); pf_it != pfCandidates->end(); pf_it++) {
00042            if (fabs(etabins[ieta]-pf_it->eta())>etahalfdist) continue;
00043            if (fabs(reco::deltaPhi(phibins[iphi],pf_it->phi()))>phihalfdist) continue;
00044            pfniso_ieta_iphi+=pf_it->pt();
00045          }
00046          sumPFNallSMDQ.push_back(pfniso_ieta_iphi);
00047        }
00048      }
00049      float evt_smdq = 0;
00050      sort(sumPFNallSMDQ.begin(),sumPFNallSMDQ.end());
00051      if (sumPFNallSMDQ.size()%2) evt_smdq = sumPFNallSMDQ[(sumPFNallSMDQ.size()-1)/2];
00052      else evt_smdq = (sumPFNallSMDQ[sumPFNallSMDQ.size()/2]+sumPFNallSMDQ[(sumPFNallSMDQ.size()-2)/2])/2.;
00053      return evt_smdq/(etadist*phidist);
00054 }