TrackAssociatorByChi2 Class Reference

#include <TrackAssociatorByChi2.h>

Inheritance diagram for TrackAssociatorByChi2:

Public Types
typedef std::map< double, SimTrack >	Chi2SimMap
typedef std::pair< reco::Track, Chi2SimMap >	RecoToSimPair
typedef std::vector < RecoToSimPair >	RecoToSimPairAssociation

Public Member Functions
virtual reco::RecoToSimCollection	associateRecoToSim (const edm::RefToBaseVector< reco::Track > &, const edm::RefVector< TrackingParticleCollection > &, const edm::Event *event=0, const edm::EventSetup *setup=0) const override
	Association Reco To Sim with Collections. More...
virtual reco::RecoToSimCollection	associateRecoToSim (edm::Handle< edm::View< reco::Track > > &tCH, edm::Handle< TrackingParticleCollection > &tPCH, const edm::Event *event=0, const edm::EventSetup *setup=0) const override
	compare reco to sim the handle of reco::Track and TrackingParticle collections More...
virtual reco::SimToRecoCollection	associateSimToReco (const edm::RefToBaseVector< reco::Track > &, const edm::RefVector< TrackingParticleCollection > &, const edm::Event *event=0, const edm::EventSetup *setup=0) const override
	Association Sim To Reco with Collections. More...
virtual reco::SimToRecoCollection	associateSimToReco (edm::Handle< edm::View< reco::Track > > &tCH, edm::Handle< TrackingParticleCollection > &tPCH, const edm::Event *event=0, const edm::EventSetup *setup=0) const override
	compare reco to sim the handle of reco::Track and TrackingParticle collections More...
	TrackAssociatorByChi2 (const edm::ESHandle< MagneticField > mF, const edm::ParameterSet &conf)
	Constructor with PSet. More...
	TrackAssociatorByChi2 (const edm::ESHandle< MagneticField > mF, double chi2Cut, bool onlyDiag, const edm::InputTag &beamspotSrc)
	Constructor with magnetic field, double, bool and InputTag. More...
	~TrackAssociatorByChi2 ()
	Destructor. More...
Public Member Functions inherited from TrackAssociatorBase
virtual reco::RecoToSimCollectionSeed	associateRecoToSim (edm::Handle< edm::View< TrajectorySeed > > &, edm::Handle< TrackingParticleCollection > &, const edm::Event *event, const edm::EventSetup *setup) const
virtual reco::RecoToSimCollectionTCandidate	associateRecoToSim (edm::Handle< TrackCandidateCollection > &, edm::Handle< TrackingParticleCollection > &, const edm::Event *event, const edm::EventSetup *setup) const
virtual reco::SimToRecoCollectionSeed	associateSimToReco (edm::Handle< edm::View< TrajectorySeed > > &, edm::Handle< TrackingParticleCollection > &, const edm::Event *event, const edm::EventSetup *setup) const
virtual reco::SimToRecoCollectionTCandidate	associateSimToReco (edm::Handle< TrackCandidateCollection > &, edm::Handle< TrackingParticleCollection > &, const edm::Event *event, const edm::EventSetup *setup) const
	TrackAssociatorBase ()
	Constructor. More...
virtual	~TrackAssociatorBase ()
	Destructor. More...

Private Member Functions
double	associateRecoToSim (reco::TrackCollection::const_iterator, TrackingParticleCollection::const_iterator, const reco::BeamSpot &) const
	compare reco::TrackCollection and TrackingParticleCollection iterators: returns the chi2 More...
double	compareTracksParam (reco::TrackCollection::const_iterator, edm::SimTrackContainer::const_iterator, const math::XYZTLorentzVectorD &, const GlobalVector &, const reco::TrackBase::CovarianceMatrix &, const reco::BeamSpot &) const
	compare reco::TrackCollection and edm::SimTrackContainer iterators: returns the chi2 More...
RecoToSimPairAssociation	compareTracksParam (const reco::TrackCollection &, const edm::SimTrackContainer &, const edm::SimVertexContainer &, const reco::BeamSpot &) const
	compare collections reco to sim More...
double	getChi2 (const reco::TrackBase::ParameterVector &rParameters, const reco::TrackBase::CovarianceMatrix &recoTrackCovMatrix, const Basic3DVector< double > &momAtVtx, const Basic3DVector< double > &vert, int charge, const reco::BeamSpot &) const
	basic method where chi2 is computed More...
std::pair< bool, reco::TrackBase::ParameterVector >	parametersAtClosestApproach (const Basic3DVector< double > &, const Basic3DVector< double > &, float, const reco::BeamSpot &) const
	propagate the track parameters of TrackinParticle from production vertex to the point of closest approach to the beam line. More...

Private Attributes
edm::InputTag	bsSrc
double	chi2cut
bool	onlyDiagonal
edm::ESHandle< MagneticField >	theMF

Detailed Description

Class that performs the association of reco::Tracks and TrackingParticles evaluating the chi2 of reco tracks parameters and sim tracks parameters. The cut can be tuned from the config file: see data/TrackAssociatorByChi2.cfi. Note that the Association Map is filled with -ch2 and not chi2 because it is ordered using std::greater: the track with the lowest association chi2 will be the first in the output map.It is possible to use only diagonal terms (associator by pulls) seeting onlyDiagonal = true in the PSet

Author

cerati, magni

Definition at line 28 of file TrackAssociatorByChi2.h.

Member Typedef Documentation

typedef std::map<double, SimTrack> TrackAssociatorByChi2::Chi2SimMap

Definition at line 31 of file TrackAssociatorByChi2.h.

typedef std::pair< reco::Track, Chi2SimMap> TrackAssociatorByChi2::RecoToSimPair

Definition at line 32 of file TrackAssociatorByChi2.h.

typedef std::vector< RecoToSimPair > TrackAssociatorByChi2::RecoToSimPairAssociation

Definition at line 33 of file TrackAssociatorByChi2.h.

Constructor & Destructor Documentation

TrackAssociatorByChi2::TrackAssociatorByChi2 ( const edm::ESHandle< MagneticField >  mF, const edm::ParameterSet &  conf  )

inline

Constructor with PSet.

Definition at line 36 of file TrackAssociatorByChi2.h.

References onlyDiagonal, and theMF.

                                                                                         :
    chi2cut(conf.getParameter<double>("chi2cut")),
    onlyDiagonal(conf.getParameter<bool>("onlyDiagonal")),
    bsSrc(conf.getParameter<edm::InputTag>("beamSpot")) {
    theMF=mF;  
    if (onlyDiagonal)
      edm::LogInfo("TrackAssociator") << " ---- Using Off Diagonal Covariance Terms = 0 ---- " <<  "\n";
    else 
      edm::LogInfo("TrackAssociator") << " ---- Using Off Diagonal Covariance Terms != 0 ---- " <<  "\n";
  }

TrackAssociatorByChi2::TrackAssociatorByChi2 ( const edm::ESHandle< MagneticField >  mF, double  chi2Cut, bool  onlyDiag, const edm::InputTag &  beamspotSrc  )

inline

Constructor with magnetic field, double, bool and InputTag.

Definition at line 48 of file TrackAssociatorByChi2.h.

References bsSrc, chi2cut, onlyDiagonal, and theMF.

                                                                                                                           {
    chi2cut=chi2Cut;
    onlyDiagonal=onlyDiag;
    theMF=mF;  
    bsSrc = beamspotSrc;
  }

TrackAssociatorByChi2::~TrackAssociatorByChi2 ( )

inline

Destructor.

Definition at line 56 of file TrackAssociatorByChi2.h.

{}

Member Function Documentation

RecoToSimCollection TrackAssociatorByChi2::associateRecoToSim ( const edm::RefToBaseVector< reco::Track > &  tC, const edm::RefVector< TrackingParticleCollection > &  tPCH, const edm::Event *  event = 0, const edm::EventSetup *  setup = 0  ) const

overridevirtual

Association Reco To Sim with Collections.

Implements TrackAssociatorBase.

Definition at line 121 of file TrackAssociatorByChi2.cc.

References edm::RefToBaseVector< T >::begin(), edm::RefToBaseVector< T >::end(), edm::Event::getByLabel(), track_associator::getChi2(), i, edm::AssociationMap< Tag >::insert(), j, LogDebug, edm::AssociationMap< Tag >::post_insert(), and edm::RefVector< C, T, F >::size().

                                                                                                {
  edm::Handle<reco::BeamSpot> recoBeamSpotHandle;
  e->getByLabel(bsSrc,recoBeamSpotHandle);
  reco::BeamSpot bs = *recoBeamSpotHandle;      

  RecoToSimCollection  outputCollection;

  //dereference the edm::Ref only once
  std::vector<const TrackingParticle*> 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: tPCH and tPC have 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;
}

virtual reco::RecoToSimCollection TrackAssociatorByChi2::associateRecoToSim ( edm::Handle< edm::View< reco::Track > > &  tCH, edm::Handle< TrackingParticleCollection > &  tPCH, const edm::Event *  event = 0, const edm::EventSetup *  setup = 0  ) const

inlineoverridevirtual

compare reco to sim the handle of reco::Track and TrackingParticle collections

Reimplemented from TrackAssociatorBase.

Definition at line 74 of file TrackAssociatorByChi2.h.

References TrackAssociatorBase::associateRecoToSim(), event(), and HcalObjRepresent::setup().

                                                                                               {
    return TrackAssociatorBase::associateRecoToSim(tCH,tPCH,event,setup);
  }

double TrackAssociatorByChi2::associateRecoToSim ( reco::TrackCollection::const_iterator  , TrackingParticleCollection::const_iterator  , const reco::BeamSpot &    ) const

private

compare reco::TrackCollection and TrackingParticleCollection iterators: returns the chi2

SimToRecoCollection TrackAssociatorByChi2::associateSimToReco ( const edm::RefToBaseVector< reco::Track > &  tC, const edm::RefVector< TrackingParticleCollection > &  tPCH, const edm::Event *  event = 0, const edm::EventSetup *  setup = 0  ) const

overridevirtual

Association Sim To Reco with Collections.

Implements TrackAssociatorBase.

Definition at line 183 of file TrackAssociatorByChi2.cc.

References edm::RefToBaseVector< T >::begin(), edm::RefToBaseVector< T >::end(), edm::Event::getByLabel(), track_associator::getChi2(), i, edm::AssociationMap< Tag >::insert(), j, LogDebug, edm::AssociationMap< Tag >::post_insert(), edm::RefVector< C, T, F >::size(), and mathSSE::sqrt().

                                                                                                 {
  edm::Handle<reco::BeamSpot> recoBeamSpotHandle;
  e->getByLabel(bsSrc,recoBeamSpotHandle);
  reco::BeamSpot bs = *recoBeamSpotHandle;      

  SimToRecoCollection  outputCollection;

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

  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;
    
    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) {
        //NOTE: tPCH and tPC have the same index for the same object
    outputCollection.insert(tPCH[tpindex],
                std::make_pair(tC[tindex],
                           -chi2));//-chi2 because the Association Map is ordered using std::greater
      }
    }
  }
  outputCollection.post_insert();
  return outputCollection;
}

virtual reco::SimToRecoCollection TrackAssociatorByChi2::associateSimToReco ( edm::Handle< edm::View< reco::Track > > &  tCH, edm::Handle< TrackingParticleCollection > &  tPCH, const edm::Event *  event = 0, const edm::EventSetup *  setup = 0  ) const

inlineoverridevirtual

compare reco to sim the handle of reco::Track and TrackingParticle collections

Reimplemented from TrackAssociatorBase.

Definition at line 83 of file TrackAssociatorByChi2.h.

References TrackAssociatorBase::associateSimToReco(), event(), and HcalObjRepresent::setup().

                                                                                               {
    return TrackAssociatorBase::associateSimToReco(tCH,tPCH,event,setup);
  }  

double TrackAssociatorByChi2::compareTracksParam ( reco::TrackCollection::const_iterator  , edm::SimTrackContainer::const_iterator  , const math::XYZTLorentzVectorD &  , const GlobalVector &  , const reco::TrackBase::CovarianceMatrix &  , const reco::BeamSpot &    ) const

private

compare reco::TrackCollection and edm::SimTrackContainer iterators: returns the chi2

TrackAssociatorByChi2::RecoToSimPairAssociation TrackAssociatorByChi2::compareTracksParam ( const reco::TrackCollection &  rtColl, const edm::SimTrackContainer &  stColl, const edm::SimVertexContainer &  svColl, const reco::BeamSpot &  bs  ) const

private

compare collections reco to sim

Definition at line 40 of file TrackAssociatorByChi2.cc.

References reco::deltaPhi(), f, i, and j.

                                                   {
  
  RecoToSimPairAssociation outputVec;

  for (TrackCollection::const_iterator track=rtColl.begin(); track!=rtColl.end(); track++){
     Chi2SimMap outMap;

    TrackBase::ParameterVector rParameters = track->parameters();

    TrackBase::CovarianceMatrix recoTrackCovMatrix = track->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();

    for (SimTrackContainer::const_iterator st=stColl.begin(); st!=stColl.end(); st++){

      Basic3DVector<double> momAtVtx(st->momentum().x(),st->momentum().y(),st->momentum().z());
      Basic3DVector<double> vert = (Basic3DVector<double>)  svColl[st->vertIndex()].position();

      std::pair<bool,reco::TrackBase::ParameterVector> params = parametersAtClosestApproach(vert, momAtVtx, st->charge(), bs);
      if (params.first){
    TrackBase::ParameterVector sParameters = params.second;
      
    TrackBase::ParameterVector diffParameters = rParameters - sParameters;
        diffParameters[2] = reco::deltaPhi(diffParameters[2],0.f);
    double chi2 = ROOT::Math::Dot(diffParameters * recoTrackCovMatrix, diffParameters);
    chi2/=5;
    if (chi2<chi2cut) outMap[chi2]=*st;
      }
    }
    outputVec.push_back(RecoToSimPair(*track,outMap));
  }
  return outputVec;
}

double TrackAssociatorByChi2::getChi2 ( const reco::TrackBase::ParameterVector &  rParameters, const reco::TrackBase::CovarianceMatrix &  recoTrackCovMatrix, const Basic3DVector< double > &  momAtVtx, const Basic3DVector< double > &  vert, int  charge, const reco::BeamSpot &  bs  ) const

private

basic method where chi2 is computed

Definition at line 83 of file TrackAssociatorByChi2.cc.

References track_associator::getChi2().

                                                   {
  return track_associator::getChi2(rParameters, recoTrackCovMatrix,momAtVtx, vert, charge, *theMF, bs);
}

pair< bool, TrackBase::ParameterVector > TrackAssociatorByChi2::parametersAtClosestApproach ( const Basic3DVector< double > &  vertex, const Basic3DVector< double > &  momAtVtx, float  charge, const reco::BeamSpot &  bs  ) const

private

propagate the track parameters of TrackinParticle from production vertex to the point of closest approach to the beam line.

Definition at line 114 of file TrackAssociatorByChi2.cc.

References reco::trackingParametersAtClosestApproachToBeamSpot().

                                                    {
  return reco::trackingParametersAtClosestApproachToBeamSpot(vertex,momAtVtx,charge, *theMF, bs);
}

Member Data Documentation

edm::InputTag TrackAssociatorByChi2::bsSrc

private

Definition at line 130 of file TrackAssociatorByChi2.h.

Referenced by TrackAssociatorByChi2().

double TrackAssociatorByChi2::chi2cut

private

Definition at line 128 of file TrackAssociatorByChi2.h.

Referenced by TrackAssociatorByChi2().

bool TrackAssociatorByChi2::onlyDiagonal

private

Definition at line 129 of file TrackAssociatorByChi2.h.

Referenced by TrackAssociatorByChi2().

edm::ESHandle<MagneticField> TrackAssociatorByChi2::theMF

private

Definition at line 127 of file TrackAssociatorByChi2.h.

Referenced by TrackAssociatorByChi2().