trkf::KFTrackState Class Reference

Extension of a TrackState to perform KalmanFilter calculations. More...

#include <KFTrackState.h>

Public Member Functions
	KFTrackState (const SVector5 &trackStatePar, const SMatrixSym55 &trackStateCov, const Plane &plane, bool trackAlongPlaneDir, int pid)
	KFTrackState (TrackState &&trackState)
bool	updateWithHitState (const HitState &hitstate)
	Update the TrackState given a HitState (they need to be on the same plane) More...
bool	combineWithTrackState (const TrackState &trackstate)
	Combine the TrackState given another TrackState (they need to be on the same plane) More...
const TrackState &	trackState () const
	Get the (const reference to the) TrackState. More...
void	setTrackState (TrackState &&s)
	Set the TrackState. More...
std::ostream &	dump (std::ostream &out=std::cout) const
	Printout information. More...
const SVector5 &	parameters () const
	This function calls the homonymous function of the stored TrackState. More...
const SMatrixSym55 &	covariance () const
const Plane &	plane () const
const Point_t &	position () const
const Vector_t &	momentum () const
int	pID () const
double	mass () const
const SVector6	parameters6D () const
bool	isTrackAlongPlaneDir () const
double	residual (const HitState &hitstate) const
double	combinedError2 (const HitState &hitstate) const
double	combinedError (const HitState &hitstate) const
double	chi2 (const HitState &hitstate) const
void	setCovariance (const SMatrixSym55 &trackStateCov)
void	setParameters (const SVector5 &trackStatePar)

Private Attributes
TrackState	fTrackState

Detailed Description

Extension of a TrackState to perform KalmanFilter calculations.

Author

G. Cerati (FNAL, MicroBooNE)

Date

2017

Version

1.0

This class extends the concept of TrackState, providing functionalities for Kalman Filter-specific calculations such as 'update' and 'combine'. It holds a TrackState by value, which is modified in place when updating or combining.

Definition at line 21 of file KFTrackState.h.

Constructor & Destructor Documentation

trkf::KFTrackState::KFTrackState ( const SVector5 &  trackStatePar, const SMatrixSym55 &  trackStateCov, const Plane &  plane, bool  trackAlongPlaneDir, int  pid  )

inline

Definition at line 24 of file KFTrackState.h.

    : fTrackState(trackStatePar, trackStateCov, plane, trackAlongPlaneDir, pid) {}

trkf::KFTrackState::KFTrackState ( TrackState &&  trackState )

inline

Definition at line 26 of file KFTrackState.h.

    : fTrackState(std::move(trackState)) { }

Member Function Documentation

double trkf::KFTrackState::chi2 ( const HitState &  hitstate ) const

inline

Definition at line 55 of file KFTrackState.h.

{ return fTrackState.chi2(hitstate); }

double trkf::KFTrackState::combinedError ( const HitState &  hitstate ) const

inline

Definition at line 54 of file KFTrackState.h.

{ return fTrackState.combinedError(hitstate); }

double trkf::KFTrackState::combinedError2 ( const HitState &  hitstate ) const

inline

Definition at line 53 of file KFTrackState.h.

{ return fTrackState.combinedError2(hitstate); }

bool KFTrackState::combineWithTrackState

(

const TrackState &

trackstate

)

Combine the TrackState given another TrackState (they need to be on the same plane)

Definition at line 17 of file KFTrackState.cxx.

                                                                     {
  // if tracks not on same plane do not update and return false
  if ( (trackstate.plane().position()-fTrackState.plane().position()).Mag2()>10e-6   ) return false;
  if ( (trackstate.plane().direction()-fTrackState.plane().direction()).Mag2()>10e-6 ) return false;
  // compute the weighted average of the two states
  const SVector5& par1 = fTrackState.parameters();
  const SVector5& par2 = trackstate.parameters();
  const SMatrixSym55& cov1 = fTrackState.covariance();
  const SMatrixSym55& cov2 = trackstate.covariance();
  SMatrixSym55&& cov = cov1 + cov2;
  bool success = cov.Invert();
  if (!success) return false;
  SMatrix55 K = cov1 * cov;
  fTrackState.setParameters( par1 + K*(par2 - par1) );
  K = K*cov2;
  fTrackState.setCovariance( K.LowerBlock() );
  return true;
}

const SMatrixSym55& trkf::KFTrackState::covariance ( ) const

inline

Definition at line 43 of file KFTrackState.h.

{ return fTrackState.covariance(); }

std::ostream& trkf::KFTrackState::dump ( std::ostream &  out = std::cout ) const

inline

Printout information.

Definition at line 62 of file KFTrackState.h.

                                                      {
      out << "KFTrackState with pID=" << pID() << " mass=" << mass()
          << "\npars=" << parameters() << " position=" << position() << " momentum=" << momentum()
          << "\ncov=\n" << covariance()
          << "\non plane with pos=" << plane().position() << " and dir=" << plane().direction() << " along=" << isTrackAlongPlaneDir() << "\n";
      return out;
    }

bool trkf::KFTrackState::isTrackAlongPlaneDir ( ) const

inline

Definition at line 50 of file KFTrackState.h.

{ return fTrackState.isTrackAlongPlaneDir(); }

double trkf::KFTrackState::mass ( ) const

inline

Definition at line 48 of file KFTrackState.h.

{ return fTrackState.mass(); }

const Vector_t& trkf::KFTrackState::momentum ( ) const

inline

Definition at line 46 of file KFTrackState.h.

{ return fTrackState.momentum(); }

const SVector5& trkf::KFTrackState::parameters ( ) const

inline

This function calls the homonymous function of the stored TrackState.

Definition at line 42 of file KFTrackState.h.

{ return fTrackState.parameters(); }

const SVector6 trkf::KFTrackState::parameters6D ( ) const

inline

Definition at line 49 of file KFTrackState.h.

{ return fTrackState.parameters6D(); }

int trkf::KFTrackState::pID ( ) const

inline

Definition at line 47 of file KFTrackState.h.

{ return fTrackState.pID(); }

const Plane& trkf::KFTrackState::plane ( ) const

inline

Definition at line 44 of file KFTrackState.h.

{ return fTrackState.plane(); }

const Point_t& trkf::KFTrackState::position ( ) const

inline

Definition at line 45 of file KFTrackState.h.

{ return fTrackState.position(); }

double trkf::KFTrackState::residual ( const HitState &  hitstate ) const

inline

Definition at line 52 of file KFTrackState.h.

{ return fTrackState.residual(hitstate); }

void trkf::KFTrackState::setCovariance ( const SMatrixSym55 &  trackStateCov )

inline

Definition at line 57 of file KFTrackState.h.

{ fTrackState.setCovariance(trackStateCov); }

void trkf::KFTrackState::setParameters ( const SVector5 &  trackStatePar )

inline

Definition at line 58 of file KFTrackState.h.

{ fTrackState.setParameters(trackStatePar); }

void trkf::KFTrackState::setTrackState ( TrackState &&  s )

inline

Set the TrackState.

Definition at line 38 of file KFTrackState.h.

{ fTrackState = std::move(s); }

const TrackState& trkf::KFTrackState::trackState ( ) const

inline

Get the (const reference to the) TrackState.

Definition at line 36 of file KFTrackState.h.

{ return fTrackState; }

bool KFTrackState::updateWithHitState

(

const HitState &

hitstate

)

Update the TrackState given a HitState (they need to be on the same plane)

Definition at line 5 of file KFTrackState.cxx.

                                                              {
  // if track and hit not on same plane do not update and return false
  if ( (hitstate.plane().position()-fTrackState.plane().position()).Mag2()>10e-6   ) return false;
  if ( (hitstate.plane().direction()-fTrackState.plane().direction()).Mag2()>10e-6 ) return false;
  // Kalman Filter update (simplified case: 1D measurement along the same coordinate as element 0 of the track parameters)
  SMatrixSym55 tmp;
  tmp(0,0) = 1./(hitstate.hitMeasErr2()+fTrackState.covariance()(0,0));
  fTrackState.setParameters( fTrackState.parameters() + fTrackState.covariance()*tmp.Col(0)*(hitstate.hitMeas() - fTrackState.parameters()(0)) );
  fTrackState.setCovariance( (fTrackState.covariance()-ROOT::Math::Similarity(fTrackState.covariance(),tmp)) );
  return true;
}

Member Data Documentation

TrackState trkf::KFTrackState::fTrackState

private

Definition at line 71 of file KFTrackState.h.

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The documentation for this class was generated from the following files:

• KFTrackState.h
• KFTrackState.cxx