MuonKinkFinder Class Reference

#include <MuonKinkFinder.h>

Public Member Functions
bool	fillTrkKink (reco::MuonQuality &quality, const Trajectory &trajectory) const
bool	fillTrkKink (reco::MuonQuality &quality, const reco::Track &track) const
void	init (const edm::EventSetup &iSetup)
	MuonKinkFinder (const edm::ParameterSet &iConfig)
	~MuonKinkFinder ()

Private Member Functions
void	cropAndInvert (AlgebraicSymMatrix55 &cov) const
double	getChi2 (const TrajectoryStateOnSurface &start, const TrajectoryStateOnSurface &other) const

Private Attributes
bool	diagonalOnly_
	use only on-diagonal terms of the covariance matrices More...
TrackTransformer	refitter_
	Track Transformer. More...
bool	usePosition_
	if true, use full 5x5 track state; if false, use only the track direction More...

Detailed Description

Definition at line 7 of file MuonKinkFinder.h.

Constructor & Destructor Documentation

MuonKinkFinder::MuonKinkFinder

(

const edm::ParameterSet &

iConfig

)

Definition at line 5 of file MuonKinkFinder.cc.

                                                             :
    diagonalOnly_(iConfig.getParameter<bool>("diagonalOnly")),
    usePosition_(iConfig.getParameter<bool>("usePosition")),
    refitter_(iConfig)
{ 
}

MuonKinkFinder::~MuonKinkFinder

(

)

Definition at line 12 of file MuonKinkFinder.cc.

{ }

Member Function Documentation

void MuonKinkFinder::cropAndInvert ( AlgebraicSymMatrix55 &  cov ) const

private

Definition at line 59 of file MuonKinkFinder.cc.

References diagonalOnly_, i, j, and usePosition_.

Referenced by getChi2().

                                                                  {
    if (usePosition_) {
        if (diagonalOnly_) {
            for (size_t i = 0; i < 5; ++i) { for (size_t j = i+1; j < 5; ++j) {
                cov(i,j) = 0;
            } }
        }
        cov.Invert();
    } else {
        // get 3x3 covariance
        AlgebraicSymMatrix33 momCov = cov.Sub<AlgebraicSymMatrix33>(0,0); // get 3x3 matrix
        if (diagonalOnly_) { momCov(0,1) = 0; momCov(0,2) = 0; momCov(1,2) = 0; }
        // invert        
        momCov.Invert();
        // place it
        cov.Place_at(momCov,0,0);
        // zero the rest
        for (size_t i = 3; i < 5; ++i) { for (size_t j = i; j < 5; ++j) { 
            cov(i,j) = 0;
        } }
    }
}

bool MuonKinkFinder::fillTrkKink	(	reco::MuonQuality &	quality,
		const Trajectory &	trajectory
	)		const

Definition at line 28 of file MuonKinkFinder.cc.

References newFWLiteAna::found, getChi2(), TrajectoryStateOnSurface::isValid(), Trajectory::measurements(), reco::MuonQuality::tkKink_position, reco::MuonQuality::trkKink, PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().

Referenced by fillTrkKink().

                                                                                              {
    const std::vector<TrajectoryMeasurement> &tms = trajectory.measurements();
    quality.trkKink = -1.0;
    quality.tkKink_position = math::XYZPoint(0,0,0);
    bool found = false; 
    for (int itm = 3, nm = tms.size() - 3;  itm < nm; ++itm) {
        TrajectoryStateOnSurface pre  = tms[itm].forwardPredictedState();
        TrajectoryStateOnSurface post = tms[itm].backwardPredictedState();
        if (!pre.isValid() || !post.isValid()) continue;
        found = true;
        double c2f = getChi2(pre,post);
        if (c2f > quality.trkKink) { 
            quality.trkKink = c2f; 
            GlobalPoint pos = (tms[itm].updatedState().isValid() ? tms[itm].updatedState() : pre).globalPosition();
            quality.tkKink_position = math::XYZPoint(pos.x(), pos.y(), pos.z());
        }
    }
    if (!found) quality.trkKink = 999;
    return found;
}

bool MuonKinkFinder::fillTrkKink	(	reco::MuonQuality &	quality,
		const reco::Track &	track
	)		const

Definition at line 18 of file MuonKinkFinder.cc.

References fillTrkKink(), refitter_, reco::MuonQuality::tkKink_position, TrackTransformer::transform(), and reco::MuonQuality::trkKink.

                                                                                        {
    std::vector<Trajectory> traj  = refitter_.transform(track);
    if (traj.size() != 1) {
        quality.trkKink = 999;
        quality.tkKink_position = math::XYZPoint(0,0,0);
        return false;
    }
    return fillTrkKink(quality, traj.front());
}

double MuonKinkFinder::getChi2 ( const TrajectoryStateOnSurface &  start, const TrajectoryStateOnSurface &  other  ) const

private

Definition at line 49 of file MuonKinkFinder.cc.

References cropAndInvert(), diffTreeTool::diff, TrajectoryStateOnSurface::hasError(), TrajectoryStateOnSurface::localError(), TrajectoryStateOnSurface::localParameters(), LocalTrajectoryError::matrix(), and LocalTrajectoryParameters::mixedFormatVector().

Referenced by fillTrkKink().

                                                                                                                 {
    if (!start.hasError() && !other.hasError()) throw cms::Exception("LogicError") << "At least one of the two states must have errors to make chi2s.\n";
    AlgebraicSymMatrix55 cov;
    if (start.hasError()) cov += start.localError().matrix();
    if (other.hasError()) cov += other.localError().matrix();
    cropAndInvert(cov);
    AlgebraicVector5 diff(start.localParameters().mixedFormatVector() - other.localParameters().mixedFormatVector());
    return ROOT::Math::Similarity(diff, cov);
}

void MuonKinkFinder::init

(

const edm::EventSetup &

iSetup

)

Definition at line 14 of file MuonKinkFinder.cc.

References refitter_, and TrackTransformer::setServices().

                                                     { 
    refitter_.setServices(iSetup);
}

Member Data Documentation

bool MuonKinkFinder::diagonalOnly_

private

use only on-diagonal terms of the covariance matrices

Definition at line 23 of file MuonKinkFinder.h.

Referenced by cropAndInvert().

TrackTransformer MuonKinkFinder::refitter_

private

Track Transformer.

Definition at line 28 of file MuonKinkFinder.h.

Referenced by fillTrkKink(), and init().

bool MuonKinkFinder::usePosition_

private

if true, use full 5x5 track state; if false, use only the track direction

Definition at line 25 of file MuonKinkFinder.h.

Referenced by cropAndInvert().