TrackAssociatorByChi2Impl Class Reference

#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
reco::RecoToSimCollection	associateRecoToSim (const edm::RefToBaseVector< reco::Track > &, const edm::RefVector< TrackingParticleCollection > &) const override
	Association Reco To Sim with Collections. More...
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...
reco::SimToRecoCollection	associateSimToReco (const edm::RefToBaseVector< reco::Track > &, const edm::RefVector< TrackingParticleCollection > &) const override
	Association Sim To Reco with Collections. More...
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 (edm::EDProductGetter const &productGetter, const MagneticField &mF, const reco::BeamSpot &bs, double chi2Cut, bool onlyDiag)
	Constructor. More...
Public Member Functions inherited from reco::TrackToTrackingParticleAssociatorBaseImpl
virtual reco::RecoToSimCollection	associateRecoToSim (const edm::Handle< edm::View< reco::Track >> &tCH, const edm::Handle< TrackingParticleCollection > &tPCH) const
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::RefVector< TrackingParticleCollection > &) const
virtual reco::SimToRecoCollection	associateSimToReco (const edm::Handle< edm::View< reco::Track >> &tCH, const edm::Handle< TrackingParticleCollection > &tPCH) 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::RefVector< TrackingParticleCollection > &) const
	TrackToTrackingParticleAssociatorBaseImpl ()
	Constructor. More...
virtual	~TrackToTrackingParticleAssociatorBaseImpl ()
	Destructor. More...

Private Attributes
const reco::BeamSpot *	beamSpot_
double	chi2cut_
const MagneticField *	mF_
bool	onlyDiagonal_
edm::EDProductGetter const *	productGetter_

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 38 of file TrackAssociatorByChi2Impl.h.

Member Typedef Documentation

Chi2SimMap

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

Definition at line 40 of file TrackAssociatorByChi2Impl.h.

RecoToSimPair

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

Definition at line 41 of file TrackAssociatorByChi2Impl.h.

RecoToSimPairAssociation

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

Definition at line 42 of file TrackAssociatorByChi2Impl.h.

Constructor & Destructor Documentation

TrackAssociatorByChi2Impl()

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

inline

Constructor.

Definition at line 59 of file TrackAssociatorByChi2Impl.h.

      : productGetter_(&productGetter), mF_(&mF), beamSpot_(&bs), chi2cut_(chi2Cut), onlyDiagonal_(onlyDiag) {}

Member Function Documentation

associateRecoToSim() [1/2]

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 14 of file TrackAssociatorByChi2Impl.cc.

References edm::RefToBaseVector< T >::begin(), cms::cuda::bs, ALCARECOTkAlJpsiMuMu_cff::charge, hltPixelTracks_cff::chi2, edm::RefToBaseVector< T >::end(), edm::first(), mps_fire::i, edm::AssociationMap< Tag >::insert(), dqmiolumiharvest::j, LogDebug, edm::AssociationMap< Tag >::post_insert(), hcal_runs::rt, edm::second(), edm::RefVector< C, T, F >::size(), cmsswSequenceInfo::tp, track_associator::trackAssociationChi2(), and reco::trackingParametersAtClosestApproachToBeamSpot().

                                                                                               {
  const BeamSpot& bs = *beamSpot_;

  RecoToSimCollection outputCollection(productGetter_);

  //dereference the Refs only once and precompute params
  std::vector<TrackingParticle const*> tPC;
  std::vector<std::pair<bool, TrackBase::ParameterVector>> tpParams;
  tPC.reserve(tPCH.size());
  tpParams.reserve(tPCH.size());
  for (auto const& ref : tPCH) {
    auto const& tp = *ref;
    tPC.push_back(&tp);

    int charge = tp.charge();
    if (charge == 0)
      tpParams.emplace_back(false, TrackBase::ParameterVector());
    else {
      using BVec = Basic3DVector<double>;
      tpParams.emplace_back(
          trackingParametersAtClosestApproachToBeamSpot(BVec(tp.vertex()), BVec(tp.momentum()), charge, *mF_, bs));
    }
  }

  int tindex = 0;
  for (RefToBaseVector<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;
      if (!tpParams[tpindex].first)
        continue;

      double chi2 = trackAssociationChi2(rParameters, recoTrackCovMatrix, tpParams[tpindex].second);

      if (chi2 < chi2cut_) {
        //-chi2 because the Association Map is ordered using std::greater
        outputCollection.insert(tC[tindex], std::make_pair(tPCH[tpindex], -chi2));
      }
    }
  }
  outputCollection.post_insert();
  return outputCollection;
}

associateRecoToSim() [2/2]

reco::RecoToSimCollection TrackAssociatorByChi2Impl::associateRecoToSim ( const edm::Handle< edm::View< reco::Track > > &  tCH, const edm::Handle< TrackingParticleCollection > &  tPCH  ) const

inlineoverride

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

Definition at line 77 of file TrackAssociatorByChi2Impl.h.

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

associateSimToReco() [1/2]

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 80 of file TrackAssociatorByChi2Impl.cc.

References edm::RefVector< C, T, F >::begin(), cms::cuda::bs, ALCARECOTkAlJpsiMuMu_cff::charge, hltPixelTracks_cff::chi2, edm::RefVector< C, T, F >::end(), mps_fire::i, edm::AssociationMap< Tag >::insert(), dqmiolumiharvest::j, LogDebug, edm::AssociationMap< Tag >::post_insert(), edm::RefToBaseVector< T >::size(), mathSSE::sqrt(), cmsswSequenceInfo::tp, track_associator::trackAssociationChi2(), and reco::trackingParametersAtClosestApproachToBeamSpot().

                                                                                               {
  const BeamSpot& bs = *beamSpot_;

  SimToRecoCollection outputCollection(productGetter_);

  //compute track parameters only once
  std::vector<TrackBase::ParameterVector> tPars;
  tPars.reserve(tC.size());
  std::vector<TrackBase::CovarianceMatrix> tCovs;
  tCovs.reserve(tC.size());
  for (auto const& ref : tC) {
    auto const& aTk = *ref;
    tPars.emplace_back(aTk.parameters());

    TrackBase::CovarianceMatrix recoTrackCovMatrix = aTk.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();
    tCovs.emplace_back(recoTrackCovMatrix);
  }

  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;
    auto const& aTP = **tp;
    int charge = aTP.charge();
    if (charge == 0)
      continue;

    LogDebug("TrackAssociator") << "=========LOOKING FOR ASSOCIATION==========="
                                << "\n"
                                << "TrackingParticle #" << tpindex << " with pt=" << sqrt(aTP.momentum().perp2())
                                << "\n"
                                << "==========================================="
                                << "\n";

    using BVec = Basic3DVector<double>;
    auto const tpBoolParams =
        trackingParametersAtClosestApproachToBeamSpot(BVec(aTP.vertex()), BVec(aTP.momentum()), charge, *mF_, bs);
    if (!tpBoolParams.first)
      continue;

    for (unsigned int tindex = 0; tindex < tC.size(); tindex++) {
      TrackBase::ParameterVector const& rParameters = tPars[tindex];
      TrackBase::CovarianceMatrix const& recoTrackCovMatrix = tCovs[tindex];

      double chi2 = trackAssociationChi2(rParameters, recoTrackCovMatrix, tpBoolParams.second);

      if (chi2 < chi2cut_) {
        //-chi2 because the Association Map is ordered using std::greater
        outputCollection.insert(*tp, std::make_pair(tC[tindex], -chi2));
      }
    }
  }
  outputCollection.post_insert();
  return outputCollection;
}

associateSimToReco() [2/2]

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

inlineoverride

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

Definition at line 84 of file TrackAssociatorByChi2Impl.h.

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

Member Data Documentation

beamSpot_

const reco::BeamSpot* TrackAssociatorByChi2Impl::beamSpot_

private

Definition at line 92 of file TrackAssociatorByChi2Impl.h.

chi2cut_

double TrackAssociatorByChi2Impl::chi2cut_

private

Definition at line 93 of file TrackAssociatorByChi2Impl.h.

mF_

const MagneticField* TrackAssociatorByChi2Impl::mF_

private

Definition at line 91 of file TrackAssociatorByChi2Impl.h.

onlyDiagonal_

bool TrackAssociatorByChi2Impl::onlyDiagonal_

private

Definition at line 94 of file TrackAssociatorByChi2Impl.h.

productGetter_

edm::EDProductGetter const* TrackAssociatorByChi2Impl::productGetter_

private

Definition at line 90 of file TrackAssociatorByChi2Impl.h.