#include <SeedFromConsecutiveHitsCreator.h>

Inheritance diagram for SeedFromConsecutiveHitsCreator:

Public Member Functions
	SeedFromConsecutiveHitsCreator (const edm::ParameterSet &cfg)
	SeedFromConsecutiveHitsCreator (const std::string &propagator="PropagatorWithMaterial", double seedMomentumForBOFF=-5.0, double aOriginTransverseErrorMultiplier=1.0, double aMinOneOverPtError=1.0)
virtual const TrajectorySeed *	trajectorySeed (TrajectorySeedCollection &seedCollection, const SeedingHitSet &ordered, const TrackingRegion &region, const edm::EventSetup &es, const SeedComparitor *filter)
virtual	~SeedFromConsecutiveHitsCreator ()
Protected Member Functions
virtual const TrajectorySeed *	buildSeed (TrajectorySeedCollection &seedCollection, const SeedingHitSet &hits, const FreeTrajectoryState &fts, const edm::EventSetup &es, const SeedComparitor *filter) const
virtual bool	checkHit (const TrajectoryStateOnSurface &tsos, const TransientTrackingRecHit::ConstRecHitPointer &hit, const edm::EventSetup &es, const SeedComparitor *filter) const
virtual CurvilinearTrajectoryError	initialError (const TrackingRegion &region, float sinTheta) const
virtual GlobalTrajectoryParameters	initialKinematic (const SeedingHitSet &hits, const TrackingRegion &region, const edm::EventSetup &es, const SeedComparitor *filter, bool &passesFilter) const
virtual TransientTrackingRecHit::RecHitPointer	refitHit (const TransientTrackingRecHit::ConstRecHitPointer &hit, const TrajectoryStateOnSurface &state) const
Protected Attributes
double	theBOFFMomentum
double	theMinOneOverPtError
double	theOriginTransverseErrorMultiplier
std::string	thePropagatorLabel

Detailed Description

Definition at line 10 of file SeedFromConsecutiveHitsCreator.h.

Constructor & Destructor Documentation

SeedFromConsecutiveHitsCreator::SeedFromConsecutiveHitsCreator ( const edm::ParameterSet & cfg ) [inline]

Definition at line 13 of file SeedFromConsecutiveHitsCreator.h.

                                                              :
    thePropagatorLabel(cfg.getParameter<std::string>("propagator")),
    theBOFFMomentum(cfg.existsAs<double>("SeedMomentumForBOFF") ? cfg.getParameter<double>("SeedMomentumForBOFF") : 5.0),
    theOriginTransverseErrorMultiplier(cfg.existsAs<double>("OriginTransverseErrorMultiplier") ? cfg.getParameter<double>("OriginTransverseErrorMultiplier") : 1.0),
    theMinOneOverPtError(cfg.existsAs<double>("MinOneOverPtError") ? cfg.getParameter<double>("MinOneOverPtError") : 1.0)
      {}

SeedFromConsecutiveHitsCreator::SeedFromConsecutiveHitsCreator	(	const std::string &	propagator = `"PropagatorWithMaterial"`,
		double	seedMomentumForBOFF = `-5.0`,
		double	aOriginTransverseErrorMultiplier = `1.0`,
		double	aMinOneOverPtError = `1.0`
	)		`[inline]`

Definition at line 20 of file SeedFromConsecutiveHitsCreator.h.

    : thePropagatorLabel(propagator), theBOFFMomentum(seedMomentumForBOFF), 
    theOriginTransverseErrorMultiplier(aOriginTransverseErrorMultiplier), theMinOneOverPtError(aMinOneOverPtError) { }

virtual SeedFromConsecutiveHitsCreator::~SeedFromConsecutiveHitsCreator ( ) [inline, virtual]

Definition at line 26 of file SeedFromConsecutiveHitsCreator.h.

{}

Member Function Documentation

const TrajectorySeed * SeedFromConsecutiveHitsCreator::buildSeed	(	TrajectorySeedCollection &	seedCollection,
		const SeedingHitSet &	hits,
		const FreeTrajectoryState &	fts,
		const edm::EventSetup &	es,
		const SeedComparitor *	filter
	)		const `[protected, virtual]`

Definition at line 104 of file SeedFromConsecutiveHitsCreator.cc.

References alongMomentum, checkHit(), SeedComparitor::compatible(), TrackingRecHit::geographicalId(), edm::EventSetup::get(), TrajectoryStateOnSurface::isValid(), trajectoryStateTransform::persistentState(), Propagator::propagate(), LargeD0_PixelPairStep_cff::propagator, edm::OwnVector< T, P >::push_back(), DetId::rawId(), refitHit(), SeedingHitSet::size(), thePropagatorLabel, patCandidatesForDimuonsSequences_cff::tracker, and KFUpdator::update().

Referenced by trajectorySeed().

{
  // get tracker
  edm::ESHandle<TrackerGeometry> tracker;
  es.get<TrackerDigiGeometryRecord>().get(tracker);
  
  // get propagator
  edm::ESHandle<Propagator>  propagatorHandle;
  es.get<TrackingComponentsRecord>().get(thePropagatorLabel, propagatorHandle);
  const Propagator*  propagator = &(*propagatorHandle);
  
  // get updator
  KFUpdator  updator;
  
  // Now update initial state track using information from seed hits.
  
  TrajectoryStateOnSurface updatedState;
  edm::OwnVector<TrackingRecHit> seedHits;
  
  const TrackingRecHit* hit = 0;
  for ( unsigned int iHit = 0; iHit < hits.size(); iHit++) {
    hit = hits[iHit]->hit();
    TrajectoryStateOnSurface state = (iHit==0) ? 
      propagator->propagate(fts,tracker->idToDet(hit->geographicalId())->surface())
      : propagator->propagate(updatedState, tracker->idToDet(hit->geographicalId())->surface());
    if (!state.isValid()) return 0;
    
    TransientTrackingRecHit::ConstRecHitPointer tth = hits[iHit]; 
    
    TransientTrackingRecHit::RecHitPointer newtth = refitHit( tth, state);
    
    if (!checkHit(state,newtth,es,filter)) return 0;

    updatedState =  updator.update(state, *newtth);
    if (!updatedState.isValid()) return 0;
    
    seedHits.push_back(newtth->hit()->clone());
  } 

  
  PTrajectoryStateOnDet const & PTraj = 
      trajectoryStateTransform::persistentState(updatedState, hit->geographicalId().rawId());
  TrajectorySeed seed(PTraj,std::move(seedHits),alongMomentum); 
  if (filter != 0 && !filter->compatible(seed)) return 0;
  seedCollection.push_back(seed);
  return &seedCollection.back();
}

bool SeedFromConsecutiveHitsCreator::checkHit	(	const TrajectoryStateOnSurface &	tsos,
		const TransientTrackingRecHit::ConstRecHitPointer &	hit,
		const edm::EventSetup &	es,
		const SeedComparitor *	filter
	)		const `[protected, virtual]`

Definition at line 165 of file SeedFromConsecutiveHitsCreator.cc.

References SeedComparitor::compatible().

Referenced by buildSeed().

{ 
    return (filter ? filter->compatible(tsos,hit) : true); 
}

CurvilinearTrajectoryError SeedFromConsecutiveHitsCreator::initialError	(	const TrackingRegion &	region,
		float	sinTheta
	)		const `[protected, virtual]`

Definition at line 83 of file SeedFromConsecutiveHitsCreator.cc.

References funct::C, max(), TrackingRegion::originRBound(), TrackingRegion::originZBound(), TrackingRegion::ptMin(), funct::sqr(), theMinOneOverPtError, and theOriginTransverseErrorMultiplier.

Referenced by trajectorySeed().

{
  // Set initial uncertainty on track parameters, using only P.V. constraint and no hit
  // information.
  AlgebraicSymMatrix55 C = ROOT::Math::SMatrixIdentity();

// FIXME: minC00. Prevent apriori uncertainty in 1/P from being too small, 
// to avoid instabilities.
// N.B. This parameter needs optimising ...
  // Probably OK based on quick study: KS 22/11/12.
  float sin2th = sqr(sinTheta);
  float minC00 = sqr(theMinOneOverPtError);
  C[0][0] = std::max(sin2th/sqr(region.ptMin()), minC00);
  float zErr = sqr(region.originZBound());
  float transverseErr = sqr(theOriginTransverseErrorMultiplier*region.originRBound());
  C[3][3] = transverseErr;
  C[4][4] = zErr*sin2th + transverseErr*(1-sin2th);

  return CurvilinearTrajectoryError(C);
}

GlobalTrajectoryParameters SeedFromConsecutiveHitsCreator::initialKinematic	(	const SeedingHitSet &	hits,
		const TrackingRegion &	region,
		const edm::EventSetup &	es,
		const SeedComparitor *	filter,
		bool &	passesFilter
	)		const `[protected, virtual]`

Reimplemented in SeedFromConsecutiveHitsStraightLineCreator, and SeedFromConsecutiveHitsTripletOnlyCreator.

Definition at line 44 of file SeedFromConsecutiveHitsCreator.cc.

References abs, GlobalTrajectoryParameters::charge(), SeedComparitor::compatible(), alignCSCRings::e, edm::EventSetup::get(), GlobalTrajectoryParameters::momentum(), TrackingRegion::origin(), GlobalTrajectoryParameters::position(), theBOFFMomentum, and Vector3DBase< T, FrameTag >::unit().

Referenced by trajectorySeed().

{
  edm::ESHandle<MagneticField> bfield;
  es.get<IdealMagneticFieldRecord>().get(bfield);

  GlobalTrajectoryParameters kine;

  TransientTrackingRecHit::ConstRecHitPointer tth1 = hits[0];
  TransientTrackingRecHit::ConstRecHitPointer tth2 = hits[1];
  const GlobalPoint& vertexPos = region.origin();

  FastHelix helix(tth2->globalPosition(), tth1->globalPosition(), vertexPos, es);
  if (helix.isValid()) {
    kine = helix.stateAtVertex().parameters();
  } else {
    GlobalVector initMomentum(tth2->globalPosition() - vertexPos);
    initMomentum *= (100./initMomentum.perp()); 
    kine = GlobalTrajectoryParameters(vertexPos, initMomentum, 1, &*bfield);
  } 

  bool isBOFF = ( std::abs(bfield->inTesla(GlobalPoint(0,0,0)).z()) < 1e-3 );
  if (isBOFF && (theBOFFMomentum > 0)) {
    kine = GlobalTrajectoryParameters(kine.position(),
                              kine.momentum().unit() * theBOFFMomentum,
                              kine.charge(),
                              &*bfield);
  }
  passesFilter = (filter ? filter->compatible(hits, kine, helix, region) : true); 
  return kine;
}

TransientTrackingRecHit::RecHitPointer SeedFromConsecutiveHitsCreator::refitHit	(	const TransientTrackingRecHit::ConstRecHitPointer &	hit,
		const TrajectoryStateOnSurface &	state
	)		const `[protected, virtual]`

Definition at line 157 of file SeedFromConsecutiveHitsCreator.cc.

Referenced by buildSeed().

{
  return hit->clone(state);
}

const TrajectorySeed * SeedFromConsecutiveHitsCreator::trajectorySeed	(	TrajectorySeedCollection &	seedCollection,
		const SeedingHitSet &	ordered,
		const TrackingRegion &	region,
		const edm::EventSetup &	es,
		const SeedComparitor *	filter
	)		`[virtual]`

Implements SeedCreator.

Definition at line 22 of file SeedFromConsecutiveHitsCreator.cc.

References buildSeed(), error, initialError(), initialKinematic(), GlobalTrajectoryParameters::momentum(), funct::sin(), SeedingHitSet::size(), and PV3DBase< T, PVType, FrameType >::theta().

{
  if ( hits.size() < 2) return 0;

  bool passesFilter = true;
  GlobalTrajectoryParameters kine = initialKinematic(hits, region, es, filter, passesFilter);
  if (!passesFilter) return 0;

  float sinTheta = sin(kine.momentum().theta());

  CurvilinearTrajectoryError error = initialError(region,  sinTheta);
  FreeTrajectoryState fts(kine, error);

  return buildSeed(seedCollection,hits,fts,es,filter); 
}