SeedMatcher Class Reference

#include <SeedMatcher.h>

Static Public Member Functions
static std::vector< int >	matchRecHitCombinations (const TrajectorySeed &seed, const FastTrackerRecHitCombinationCollection &recHitCombinationCollection, const std::vector< SimTrack > &simTrackCollection, double maxMatchEstimator, const Propagator &propagator, const MagneticField &magneticField, const TrackerGeometry &trackerGeometry)
static double	matchSimTrack (const TrajectoryStateOnSurface &seedState, const SimTrack &simTrack, const Propagator &propagator, const MagneticField &magneticField)

Detailed Description

Definition at line 14 of file SeedMatcher.h.

Member Function Documentation

std::vector< int32_t > SeedMatcher::matchRecHitCombinations ( const TrajectorySeed &  seed, const FastTrackerRecHitCombinationCollection &  recHitCombinationCollection, const std::vector< SimTrack > &  simTrackCollection, double  maxMatchEstimator, const Propagator &  propagator, const MagneticField &  magneticField, const TrackerGeometry &  trackerGeometry  )

static

Definition at line 14 of file SeedMatcher.cc.

References PTrajectoryStateOnDet::detId(), Exception, TrackerGeometry::idToDet(), matchSimTrack(), mps_fire::result, simTrackMatching_cfi::simTrack, TrajectorySeed::startingState(), and trajectoryStateTransform::transientState().

Referenced by TrackCandidateProducer::produce().

{

    // container for result
    std::vector<int32_t> result;
    
    // seed state
    PTrajectoryStateOnDet ptod =seed.startingState();
    DetId seedState_detId(ptod.detId());
    const GeomDet * seedState_det = trackerGeometry.idToDet(seedState_detId);
    const Surface * seedState_surface=&seedState_det->surface();
    TrajectoryStateOnSurface seedState(trajectoryStateTransform::transientState(ptod,seedState_surface,&magneticField));
    
    // find matches
    int nSimTracks = simTrackCollection.size();
    for(unsigned recHitCombinationIndex = 0;recHitCombinationIndex < recHitCombinationCollection.size(); recHitCombinationIndex++)
    {
    const auto & recHitCombination = recHitCombinationCollection[recHitCombinationIndex];
    int simTrackIndex = recHitCombination.back()->simTrackId(0);
    if(simTrackIndex < 0 || simTrackIndex >= nSimTracks)
    {
        throw cms::Exception("SeedMatcher") << "SimTrack index out of range: " << simTrackIndex << std::endl;
    }
    const auto & simTrack = simTrackCollection[recHitCombination.back()->simTrackId(0)];
    double matchEstimator = matchSimTrack(seedState,simTrack,propagator,magneticField);
    if(matchEstimator < maxMatchEstimator)
    {
        result.push_back(recHitCombinationIndex);
    }
    }
    return result;
}

double SeedMatcher::matchSimTrack ( const TrajectoryStateOnSurface &  seedState, const SimTrack &  simTrack, const Propagator &  propagator, const MagneticField &  magneticField  )

static

Definition at line 53 of file SeedMatcher.cc.

References PV3DBase< T, PVType, FrameType >::basicVector(), CoreSimTrack::charge(), Basic3DVector< T >::dot(), relativeConstraints::error, TrajectoryStateOnSurface::globalMomentum(), TrajectoryStateOnSurface::globalPosition(), TrajectoryStateOnSurface::isValid(), TrajectoryStateOnSurface::localError(), TrajectoryStateOnSurface::localParameters(), seedCreatorFromRegionConsecutiveHitsEDProducer_cff::magneticField, LocalTrajectoryError::matrix(), Propagator::propagate(), TrajectoryStateOnSurface::surface(), SimTrack::trackerSurfaceMomentum(), SimTrack::trackerSurfacePosition(), and LocalTrajectoryParameters::vector().

Referenced by matchRecHitCombinations().

{
    
    // simtrack and simvertex at tracker surface
    GlobalPoint simTrack_atTrackerSurface_position(simTrack.trackerSurfacePosition().x(),
                           simTrack.trackerSurfacePosition().y(),
                           simTrack.trackerSurfacePosition().z());    
    GlobalVector simTrack_atTrackerSurface_momentum(simTrack.trackerSurfaceMomentum().x(),
                            simTrack.trackerSurfaceMomentum().y(),
                            simTrack.trackerSurfaceMomentum().z());
    
    // no match if seedstate and simtrack in oposite direction
    if ( simTrack_atTrackerSurface_position.basicVector().dot(simTrack_atTrackerSurface_momentum.basicVector() ) 
     * seedState.globalPosition().basicVector().dot(seedState.globalMomentum().basicVector()) <0. )
    {
    return 9999.;
    }
    
    // find simtrack state on surface of seed state
    GlobalTrajectoryParameters simTrack_atTrackerSurface_parameters(simTrack_atTrackerSurface_position,
                                    simTrack_atTrackerSurface_momentum,
                                    simTrack.charge(),
                                    &magneticField);
    FreeTrajectoryState simtrack_atTrackerSurface_state(simTrack_atTrackerSurface_parameters);
    TrajectoryStateOnSurface simtrack_atSeedStateSurface_state = propagator.propagate(simtrack_atTrackerSurface_state,seedState.surface());
    
    // simtrack does not propagate to surface of seed state
    if (!simtrack_atSeedStateSurface_state.isValid())
    {
    return 9999.;
    }
    
    // simtrack and seed state have opposite direction
    if ( simtrack_atSeedStateSurface_state.globalPosition().basicVector().dot(simtrack_atSeedStateSurface_state.globalMomentum().basicVector()) 
     * seedState.globalPosition().basicVector().dot(seedState.globalMomentum().basicVector()) <0. )
    {
    return 9999.;
    }

    AlgebraicVector5 difference(seedState.localParameters().vector() - simtrack_atSeedStateSurface_state.localParameters().vector());
    AlgebraicSymMatrix55 error(seedState.localError().matrix());
    if(!error.Invert())
    {
    edm::LogWarning("FastSim SeedToSimTrackMatcher") <<"Cannot invert seed state error matrix => no match...";
    return 9999.;
    }

    return ROOT::Math::Similarity(difference,error);
}