#include <TrackAssociatorByChi2Impl.h>

Inheritance diagram for TrackAssociatorByChi2Impl:

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 override
	Association Reco To Sim with Collections. More...

virtual reco::RecoToSimCollection	associateRecoToSim (const edm::Handle< edm::View< reco::Track > > &tCH, const edm::Handle< TrackingParticleCollection > &tPCH) 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 override
	Association Sim To Reco with Collections. More...

virtual reco::SimToRecoCollection	associateSimToReco (const edm::Handle< edm::View< reco::Track > > &tCH, const edm::Handle< TrackingParticleCollection > &tPCH) const override
	compare reco to sim the handle of reco::Track and TrackingParticle collections More...

	TrackAssociatorByChi2Impl (const MagneticField &mF, const reco::BeamSpot &bs, double chi2Cut, bool onlyDiag)
	Constructor. More...

Public Member Functions inherited from reco::TrackToTrackingParticleAssociatorBaseImpl
virtual reco::RecoToSimCollectionSeed	associateRecoToSim (const edm::Handle< edm::View< TrajectorySeed > > &, const edm::Handle< TrackingParticleCollection > &) const

virtual reco::RecoToSimCollectionTCandidate	associateRecoToSim (const edm::Handle< TrackCandidateCollection > &, const edm::Handle< TrackingParticleCollection > &) const

virtual reco::SimToRecoCollectionSeed	associateSimToReco (const edm::Handle< edm::View< TrajectorySeed > > &, const edm::Handle< TrackingParticleCollection > &) const

virtual reco::SimToRecoCollectionTCandidate	associateSimToReco (const edm::Handle< TrackCandidateCollection > &, const edm::Handle< TrackingParticleCollection > &) const

	TrackToTrackingParticleAssociatorBaseImpl ()
	Constructor. More...

virtual	~TrackToTrackingParticleAssociatorBaseImpl ()
	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
double	chi2cut

bool	onlyDiagonal

const reco::BeamSpot *	theBeamSpot

const 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 35 of file TrackAssociatorByChi2Impl.h.

Member Typedef Documentation

typedef std::map<double, SimTrack> TrackAssociatorByChi2Impl::Chi2SimMap

Definition at line 38 of file TrackAssociatorByChi2Impl.h.

typedef std::pair< reco::Track, Chi2SimMap> TrackAssociatorByChi2Impl::RecoToSimPair

Definition at line 39 of file TrackAssociatorByChi2Impl.h.

typedef std::vector< RecoToSimPair > TrackAssociatorByChi2Impl::RecoToSimPairAssociation

Definition at line 40 of file TrackAssociatorByChi2Impl.h.

Constructor & Destructor Documentation

TrackAssociatorByChi2Impl::TrackAssociatorByChi2Impl	(	const MagneticField &	mF,
		const reco::BeamSpot &	bs,
		double	chi2Cut,
		bool	onlyDiag
	)

inline

Constructor.

Definition at line 57 of file TrackAssociatorByChi2Impl.h.

                                                           :
     theMF(&mF),
     theBeamSpot(&bs),
     chi2cut(chi2Cut),
     onlyDiagonal(onlyDiag) {
     }

Member Function Documentation

RecoToSimCollection TrackAssociatorByChi2Impl::associateRecoToSim	(	const edm::RefToBaseVector< reco::Track > &	tC,
		const edm::RefVector< TrackingParticleCollection > &	tPCH
	)		const

overridevirtual

Association Reco To Sim with Collections.

Implements reco::TrackToTrackingParticleAssociatorBaseImpl.

Definition at line 121 of file TrackAssociatorByChi2Impl.cc.

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

                                                                                                                               {
 
   const reco::BeamSpot& bs = *theBeamSpot;
 
   RecoToSimCollection  outputCollection;
 
   //dereference the edm::Refs only once
   std::vector<TrackingParticle 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) {
     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 TrackAssociatorByChi2Impl::associateRecoToSim	(	const edm::Handle< edm::View< reco::Track > > &	tCH,
		const edm::Handle< TrackingParticleCollection > &	tPCH
	)		const

inlineoverridevirtual

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

Reimplemented from reco::TrackToTrackingParticleAssociatorBaseImpl.

Definition at line 78 of file TrackAssociatorByChi2Impl.h.

                                                                                              {
     return TrackToTrackingParticleAssociatorBaseImpl::associateRecoToSim(tCH,tPCH);
   }

double TrackAssociatorByChi2Impl::associateRecoToSim	(	reco::TrackCollection::const_iterator	,
		TrackingParticleCollection::const_iterator	,
		const reco::BeamSpot &
	)		const

private

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

SimToRecoCollection TrackAssociatorByChi2Impl::associateSimToReco	(	const edm::RefToBaseVector< reco::Track > &	tC,
		const edm::RefVector< TrackingParticleCollection > &	tPCH
	)		const

overridevirtual

Association Sim To Reco with Collections.

Implements reco::TrackToTrackingParticleAssociatorBaseImpl.

Definition at line 179 of file TrackAssociatorByChi2Impl.cc.

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

                                                                                                                               {
   const reco::BeamSpot& bs = *theBeamSpot;
 
   SimToRecoCollection  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;
 }

virtual reco::SimToRecoCollection TrackAssociatorByChi2Impl::associateSimToReco	(	const edm::Handle< edm::View< reco::Track > > &	tCH,
		const edm::Handle< TrackingParticleCollection > &	tPCH
	)		const

inlineoverridevirtual

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

Reimplemented from reco::TrackToTrackingParticleAssociatorBaseImpl.

Definition at line 85 of file TrackAssociatorByChi2Impl.h.

                                                                                              {
     return TrackToTrackingParticleAssociatorBaseImpl::associateSimToReco(tCH,tPCH);
   }  

double TrackAssociatorByChi2Impl::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

TrackAssociatorByChi2Impl::RecoToSimPairAssociation TrackAssociatorByChi2Impl::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 TrackAssociatorByChi2Impl.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 TrackAssociatorByChi2Impl::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 TrackAssociatorByChi2Impl.cc.

References track_associator::getChi2().

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

pair< bool, TrackBase::ParameterVector > TrackAssociatorByChi2Impl::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 TrackAssociatorByChi2Impl.cc.

References reco::trackingParametersAtClosestApproachToBeamSpot().

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