TrackGenAssociatorByChi2Impl.cc

Go to the documentation of this file.

#include "TrackGenAssociatorByChi2Impl.h"
#include "SimDataFormats/TrackingAnalysis/interface/TrackingParticle.h"

#include "DataFormats/GeometrySurface/interface/Line.h"

#include "SimTracker/TrackAssociation/interface/trackAssociationChi2.h"

using namespace edm;
using namespace reco;
using namespace std;

double TrackGenAssociatorByChi2Impl::getChi2(const TrackBase::ParameterVector& rParameters,
                                         const TrackBase::CovarianceMatrix& recoTrackCovMatrix,
                                         const Basic3DVector<double>& momAtVtx,
                                         const Basic3DVector<double>& vert,
                                         int charge,
                                         const reco::BeamSpot& bs) const{
  return track_associator::trackAssociationChi2(rParameters, recoTrackCovMatrix,momAtVtx, vert, charge, *theMF, bs);
}

RecoToGenCollection TrackGenAssociatorByChi2Impl::associateRecoToGen(const edm::RefToBaseVector<reco::Track>& tC, 
                                                                     const edm::RefVector<GenParticleCollection>& tPCH) const {
  reco::BeamSpot const& bs = *theBeamSpot;

  RecoToGenCollection  outputCollection;

  //dereference the edm::Refs only once
  std::vector<GenParticle const*> tPC;
  tPC.reserve(tPCH.size());
  for(auto const& ref: tPCH) {
    tPC.push_back(&(*ref));
  }

  int tindex=0;
  for (RefToBaseVector<reco::Track>::const_iterator rt=tC.begin(); rt!=tC.end(); rt++, tindex++){

    LogDebug("TrackAssociator") << "=========LOOKING FOR ASSOCIATION===========" << "\n"
                << "rec::Track #"<<tindex<<" with pt=" << (*rt)->pt() <<  "\n"
                << "===========================================" << "\n";
 
    TrackBase::ParameterVector rParameters = (*rt)->parameters();

    TrackBase::CovarianceMatrix recoTrackCovMatrix = (*rt)->covariance();
    if (onlyDiagonal){
      for (unsigned int i=0;i<5;i++){
    for (unsigned int j=0;j<5;j++){
      if (i!=j) recoTrackCovMatrix(i,j)=0;
    }
      }
    } 

    recoTrackCovMatrix.Invert();

    int tpindex =0;
    for (auto tp=tPC.begin(); tp!=tPC.end(); tp++, ++tpindex){
    
      //skip tps with a very small pt
      //if (sqrt((*tp)->momentum().perp2())<0.5) continue;
      int charge = (*tp)->charge();
      if (charge==0) continue;
      Basic3DVector<double> momAtVtx((*tp)->momentum().x(),(*tp)->momentum().y(),(*tp)->momentum().z());
      Basic3DVector<double> vert=(Basic3DVector<double>) (*tp)->vertex();

      double chi2 = getChi2(rParameters,recoTrackCovMatrix,momAtVtx,vert,charge,bs);
      
      if (chi2<chi2cut) {
        //NOTE: tPC and tPCH use the same index for the same object
    outputCollection.insert(tC[tindex], 
                std::make_pair(tPCH[tpindex],
                           -chi2));//-chi2 because the Association Map is ordered using std::greater
      }
    }
  }
  outputCollection.post_insert();
  return outputCollection;
}


GenToRecoCollection TrackGenAssociatorByChi2Impl::associateGenToReco(const edm::RefToBaseVector<reco::Track>& tC, 
                                                                     const edm::RefVector<GenParticleCollection>& tPCH) const {
  reco::BeamSpot const& bs = *theBeamSpot;      

  GenToRecoCollection  outputCollection;

  int tpindex =0;
  for (auto tp=tPCH.begin(); tp!=tPCH.end(); tp++, ++tpindex){
    
    //skip tps with a very small pt
    //if (sqrt((*tp)->momentum().perp2())<0.5) continue;
    int charge = (*tp)->charge();
    if (charge==0) continue;
    
    LogDebug("TrackAssociator") << "=========LOOKING FOR ASSOCIATION===========" << "\n"
                << "TrackingParticle #"<<tpindex<<" with pt=" << sqrt((*tp)->momentum().perp2()) << "\n"
                << "===========================================" << "\n";
    
    Basic3DVector<double> momAtVtx((*tp)->momentum().x(),(*tp)->momentum().y(),(*tp)->momentum().z());
    Basic3DVector<double> vert((*tp)->vertex().x(),(*tp)->vertex().y(),(*tp)->vertex().z());
      
    int tindex=0;
    for (RefToBaseVector<reco::Track>::const_iterator rt=tC.begin(); rt!=tC.end(); rt++, tindex++){
      
      TrackBase::ParameterVector rParameters = (*rt)->parameters();      
      TrackBase::CovarianceMatrix recoTrackCovMatrix = (*rt)->covariance();
      if (onlyDiagonal) {
    for (unsigned int i=0;i<5;i++){
      for (unsigned int j=0;j<5;j++){
        if (i!=j) recoTrackCovMatrix(i,j)=0;
      }
    }
      }
      recoTrackCovMatrix.Invert();
      
      double chi2 = getChi2(rParameters,recoTrackCovMatrix,momAtVtx,vert,charge,bs);
      
      if (chi2<chi2cut) {
    outputCollection.insert(*tp,
                std::make_pair(tC[tindex],
                           -chi2));//-chi2 because the Association Map is ordered using std::greater
      }
    }
  }
  outputCollection.post_insert();
  return outputCollection;
}