#include <GsfConstraintAtVertex.h>

Public Member Functions
TrajectoryStateOnSurface	constrainAtBeamSpot (const reco::GsfTrack &, const reco::BeamSpot &) const
	(multi)TSOS after including the beamspot More...

TrajectoryStateOnSurface	constrainAtPoint (const reco::GsfTrack &, const GlobalPoint &globalPosition, const GlobalError &globalError) const
	(multi)TSOS after including a point with covariance matrix More...

TrajectoryStateOnSurface	constrainAtVertex (const reco::GsfTrack &, const reco::Vertex &) const
	(multi)TSOS after include a vertex More...

	GsfConstraintAtVertex (const TrackerGeometry geometry, const MagneticField magField)

Private Attributes
const TrackerGeometry *	geometry_

GsfPropagatorAdapter	gsfPropagator_

GsfMultiStateUpdator	gsfUpdator_

const MagneticField *	magField_

MultiTrajectoryStateTransform	multiStateTransformer_

TransverseImpactPointExtrapolator	tipExtrapolator_

Detailed Description

Definition at line 23 of file GsfConstraintAtVertex.h.

Constructor & Destructor Documentation

GsfConstraintAtVertex::GsfConstraintAtVertex	(	const TrackerGeometry *	geometry,
		const MagneticField *	magField
	)

explicit

Definition at line 19 of file GsfConstraintAtVertex.cc.

     : geometry_(geometry),
       magField_(magField),
       gsfPropagator_(AnalyticalPropagator(magField, anyDirection)),
       tipExtrapolator_(gsfPropagator_) {}

Member Function Documentation

TrajectoryStateOnSurface GsfConstraintAtVertex::constrainAtBeamSpot	(	const reco::GsfTrack &	track,
		const reco::BeamSpot &	beamSpot
	)		const

(multi)TSOS after including the beamspot

Definition at line 25 of file GsfConstraintAtVertex.cc.

References constrainAtPoint(), reco::BeamSpot::rotatedCovariance3D(), reco::BeamSpot::x0(), reco::BeamSpot::y0(), and reco::BeamSpot::z0().

Referenced by GsfElectronAlgo::ElectronData::calculateTSOS().

                                                                                                         {
   //
   // Beamspot (global co-ordinates)
   //
   GlobalPoint bsPosGlobal(beamSpot.x0(), beamSpot.y0(), beamSpot.z0());
   GlobalError bsCovGlobal(beamSpot.rotatedCovariance3D());
   //
   return constrainAtPoint(track, bsPosGlobal, bsCovGlobal);
 }

TrajectoryStateOnSurface GsfConstraintAtVertex::constrainAtPoint	(	const reco::GsfTrack &	track,
		const GlobalPoint &	globalPosition,
		const GlobalError &	globalError
	)		const

(multi)TSOS after including a point with covariance matrix

Definition at line 47 of file GsfConstraintAtVertex.cc.

References TRecHit2DPosConstraint::build(), TransverseImpactPointExtrapolator::extrapolate(), geometry_, gsfUpdator_, MultiTrajectoryStateTransform::innerStateOnSurface(), TrajectoryStateOnSurface::isValid(), magField_, multiStateTransformer_, TrajectoryStateOnSurface::surface(), tipExtrapolator_, GloballyPositioned< T >::toLocal(), ErrorFrameTransformer::transform(), and GsfMultiStateUpdator::update().

Referenced by constrainAtBeamSpot(), and constrainAtVertex().

                                                                                                        {
   //
   // Track on TIP plane
   //
   TrajectoryStateOnSurface innerState = multiStateTransformer_.innerStateOnSurface(track, *geometry_, magField_);
   if (!innerState.isValid())
     return TrajectoryStateOnSurface();
   TrajectoryStateOnSurface tipState = tipExtrapolator_.extrapolate(innerState, globalPosition);
   if (!tipState.isValid())
     return TrajectoryStateOnSurface();
   //
   // RecHit from beam spot
   //
   LocalError bsCovLocal = ErrorFrameTransformer().transform(globalError, tipState.surface());
   auto bsHit =
       TRecHit2DPosConstraint::build(tipState.surface().toLocal(globalPosition), bsCovLocal, &tipState.surface());
   //
   // update with constraint
   //
   TrajectoryStateOnSurface updatedState = gsfUpdator_.update(tipState, *bsHit);
   if (!updatedState.isValid()) {
     edm::LogWarning("GsfConstraintAtVertex") << " GSF update with vertex constraint failed";
     return TrajectoryStateOnSurface();
   }
 
   return updatedState;
 }

TrajectoryStateOnSurface GsfConstraintAtVertex::constrainAtVertex	(	const reco::GsfTrack &	track,
		const reco::Vertex &	vertex
	)		const

(multi)TSOS after include a vertex

Definition at line 36 of file GsfConstraintAtVertex.cc.

References constrainAtPoint(), reco::Vertex::covariance(), and reco::Vertex::position().

                                                                                                   {
   //
   // Beamspot (global co-ordinates)
   //
   GlobalPoint vtxPosGlobal(vertex.position().x(), vertex.position().y(), vertex.position().z());
   GlobalError vtxCovGlobal(vertex.covariance());
   //
   return constrainAtPoint(track, vtxPosGlobal, vtxCovGlobal);
 }