PaTrack Class Reference

#include <PaTrack.h>

Public Member Functions
float	Zmax () const
	Z coordinate of the most downstram detector of the track.
float	Zmin () const
	Z coordinate of the most upstream detector of the track.
float	ZLast () const
	Z of the last measured point.
float	ZFirst () const
	Z of the first measured point.
int	CountNHits ()
	Count NHits in hit pattern and store it in "nhits" data member.
int	NHits () const
	Number of hits.
const float &	Chi2tot () const
	Total $\chi^2$ .
int	Ndf () const
	Number degrees of freedom.
const float &	MeanTime () const
	Track time (with respect to trigger time) in [ns].
const float &	SigmaTime () const
	Error of track time calculated from approximate errors of individual hits' times (0 if track time is unknown).
const float &	XX0 () const
	Track pass in units of rafiation lengthes (X/X0).
int	NTPar () const
	Number of trajectory parameters.
const PaTPar &	vTPar (int i) const
	Trajectory parameter # i.
bool	Extrapolate (double Z, PaTPar &Hout) const
	Extrapolate track to position Z.
bool	Extrap (double Z, PaTPar &Hout) const
	The same as Extrapolate but without multiple scattering and energy losses.
int	Q () const
	charge
bool	HasMom () const
	"true" if momentum had been defined
float	qP () const
	track momentum with sign (charge*\|P\|)
int	NRichInf () const
	Rich information array size.
const float &	RichInf (int i) const
	Rich information array element # i.
TBits	HitsExpected () const
	"Expected" hit pattern
TBits	HitsFound () const
	"Found" hit pattern
int	NHitsFoundInDetect (string str) const
	returns number of found hits in detectors with name begins on substring "str" (e.g. NHitsFoundInDetect("FI") gives number of hits in SciFi)
int	NHitsFoundInRange (double Zmin, double Zmax) const
	returns number of found hits in detectors with Z positions within specified range [Zmin; Zmax]
const vector< Int_t > &	vHitRef () const
	References to PaHits of this track (not stored in "standard" mDST).
float	FieldInteg (float &r) const
	Estimation of the field integral [T*m] "accumulated" by this track.
bool	QuickKF (int dir, int mode)
	Quick (no mult. scattering corrections) Kalman fit through already found hits.
bool	FullKF (int dir)
	Kalman fit through already found hits (no hits re-assignment) with use of material maps (if switched ON).
double	GetSmoothed (PaTPar &Hout, string detname, bool flg)
	Calculate "smoothed" track parameters on the detector with name "detname" and returns Chi2/ndf. (function returns "-1" if this track do not cross detector "detname").
double	GetSmoothed (PaTPar &Hout, int ipl, bool flg)
	Calculate "smoothed" track parameters on the plane # ipl and returns Chi2/ndf. (function returns "-1" value in the case of problem).
double	GetSmoothed (PaTPar &Hout, double Z)
	Calculate "smoothed" track parameters at given Z and returns Chi2/ndf. If track do not cross plane X, returns "-1".
bool	KFdone ()
	return "true" if Kalman fit had been done in both directions for this track.
int	iHit (string detname)
	return hit reference to the track's hit on the detector "detname" or "-1" if there is no hit associated to track on this detector
int	KeepOnly (const list< string > &detectors)
	Remove all hits from the track excluding hits of detectors with names specified in "detectors" (only few first letters of detector names are allowed).
bool	CanBeMuon () const
	Check if the track is a possibly misidentified muon.
bool	CrossYokeSM2 (bool strict=true) const
	Check if the track passes through the SM2 yoke.
bool	PointsHodoscopes () const
	Check if the track points to a trigger that fired. It is checked that a track goes through the active area of one of the trigger hodoscope pairs that gave the trigger.
int	iMCtrack () const
	corresponding MC track index (or -1 in not associated)
int	iParticle () const
	corresponding Particle index
const UInt_t *	FoundHitsBitMap () const
	return "Found hits" bitmap as plane array (size = HIT_MAP_SIZE defined in PaSetup.h)
void	SetMCtrack (int i)
	Set corresponding MC track index.

Detailed Description

Track.

Reconstructed charged track.
This class contains information, that normally is not needed for physical analysis but for various kinds of performance studies only. For physics, use PaParticle instead.

Author:: Sergei.Gerassimov@cern.ch

Member Function Documentation

bool PaTrack::CanBeMuon ( void ) const

Check if the track is a possibly misidentified muon.

It is checked if the track goes through the hole of COMPASS absorber system.

Author:: Konrad.Klimaszewski@cern.ch

References PaSetup::Detector(), PaTPar::Extrapolate(), PaSetup::iDetector(), PaDetect::InActive(), PaTPar::Mom(), NTPar(), Q(), PaSetup::Ref(), Phast::Ref(), PaEvent::RunNum(), vTPar(), PaDetect::Z(), and ZLast().

Referenced by PaVertex::iMuPrim().

const float& PaTrack::Chi2tot ( ) const [inline]

Total $\chi^2$ .

Estimation of total $\chi^2$ as $\Sigma \delta\chi^2_i$ of every update step on backward Kalman fit of the track

Referenced by FullKF(), and QuickKF().

bool PaTrack::CrossYokeSM2 ( bool strict = true ) const

Check if the track passes through the SM2 yoke.

Parameters:

strict

- take into account the extrapolation error

Author:: Konrad.Klimaszewski@cern.ch

References PaTPar::Extrapolate(), PaField::getMagInfo(), NTPar(), PaSetup::Ref(), vTPar(), and ZLast().

Referenced by PaVertex::iMuPrim().

bool PaTrack::Extrapolate	(	double	Z,
		PaTPar &	Hout
	)			const

Extrapolate track to position Z.

Takes track parameters (PaTPar) closest to desired Z position (if more than 1 is stored) and extrapolate it. If track has it's parameters only in the first measured point, then this PaTPar is used.
Extrapolated track parameters are returned via "Hout".
Function returns "false" if extrapolation had failed.

References PaTPar::Extrapolate(), NTPar(), and vTPar().

float PaTrack::FieldInteg ( float & r ) const

Estimation of the field integral [T*m] "accumulated" by this track.

Parameters:

r

- ratio of field intergal in Z range [1-st track point; 1000cm] to full field integral

References NTPar(), vTPar(), and ZLast().

bool PaTrack::FullKF ( int dir )

Kalman fit through already found hits (no hits re-assignment) with use of material maps (if switched ON).

Accumulated fraction of rad. lengthes is stored into radLenFr datamember

Parameters:

dir

- fit direction

  
  Input:
  
  dir =  1 - fit in  forward direction (resulting helix is last  element of vecTPar)
  dir = -1 - fit in backward direction (resulting helix is first element of vecTPar)

Kalman fit through already found hits (no hits re-assignment) with use of material maps (if switched ON) Accumulated fraction of rad. lengthes is stored into radLenFr datamember

Parameters:

dir

- fit direction

  
  Input:
  
  dir =  1 - fit in  forward direction (resulting helix is last  element of vecTPar)
  dir = -1 - fit in backward direction (resulting helix is first element of vecTPar)

References PaTPar::AddNoise(), Chi2tot(), PaSetup::Detector(), PaTPar::DirCos(), PaTPar::Extrapolate(), PaTPar::HasMom(), PaTPar::HitChi2(), PaDetect::InActive(), PaMaterialMaps::InMaterialMap(), PaSetup::MaterialMaps(), PaDetect::Name(), PaTPar::Path(), PaEvent::Print(), PaHit::Print(), PaTPar::Print(), QuickKF(), PaDetect::RadLen(), PaTPar::RadLenFr(), Phast::Ref(), PaSetup::Ref(), PaTPar::Update(), and PaDetect::Z().

double PaTrack::GetSmoothed	(	PaTPar &	Hout,
		double	Z
	)

Calculate "smoothed" track parameters at given Z and returns Chi2/ndf. If track do not cross plane X, returns "-1".

Parameters:

	Hout	- output smoothed helix
	Z	- input: coordinate along the beam, where smoothed track parameters has to be calculated

References PaTPar::Extrapolate(), PaTPar::Print(), and PaTPar::Update().

double PaTrack::GetSmoothed	(	PaTPar &	Hout,
		int	ipl,
		bool	flg
	)

Calculate "smoothed" track parameters on the plane # ipl and returns Chi2/ndf. (function returns "-1" value in the case of problem).

Parameters:

	Hout	- output smoothed helix
	ipl	- input: plane number where smoothed track parameters has to be calculated
	flg	- input: if == false, measurement on the current plane is excluded. If there is no hit on the plane ipl, this flag has no effect.

References KFdone(), PaEvent::Print(), PaTPar::Print(), and PaTPar::Update().

double PaTrack::GetSmoothed	(	PaTPar &	Hout,
		string	detname,
		bool	flg
	)

Calculate "smoothed" track parameters on the detector with name "detname" and returns Chi2/ndf. (function returns "-1" if this track do not cross detector "detname").

Parameters:

	Hout	- output smoothed helix
	detname	- input: detector name where smoothed track parameters has to be calculated
	flg	- input: if == false, measurement on the current plane is excluded. If there is no hit on the detector detname, this flag has no effect.

References PaSetup::iDetector(), and PaSetup::Ref().

int PaTrack::KeepOnly ( const list< string > & detectors )

Remove all hits from the track excluding hits of detectors with names specified in "detectors" (only few first letters of detector names are allowed).

Returns number of left over hits.

Example: If list contains 2 elements "FI" and "SI" all hits excluding hits in silicon detectors and SciFi will be removed.

References CountNHits(), PaSetup::Detector(), PaDetect::Name(), PaSetup::NDetectors(), and PaSetup::Ref().

int PaTrack::Ndf ( ) const [inline]

Number degrees of freedom.

Number degrees of freedom of the track fit.

References HasMom(), and NHits().

bool PaTrack::PointsHodoscopes ( ) const

Check if the track points to a trigger that fired. It is checked that a track goes through the active area of one of the trigger hodoscope pairs that gave the trigger.

Author:: Konrad.Klimaszewski@cern.ch

References PaSetup::Detector(), PaTPar::Extrapolate(), PaField::getMagInfo(), PaSetup::iDetector(), NTPar(), PaSetup::Ref(), Phast::Ref(), PaEvent::RunNum(), PaEvent::TrigMask(), vTPar(), PaTPar::X(), PaTPar::Y(), and PaEvent::Year().

Referenced by PaVertex::iMuPrim().

int PaTrack::Q ( ) const [inline]

charge

Warning:: If the momentum of track is unknown, this function prints a message and returns 999

Referenced by CanBeMuon(), and PaVertex::iMuPrim().

bool PaTrack::QuickKF	(	int	dir,
		int	mode
	)

Quick (no mult. scattering corrections) Kalman fit through already found hits.

Parameters:

	dir	- fit direction
	mode	- defines how to fit

    Input:
    
    dir =  1 - fit in downstream direction (resulting helix is last  element of vecTPar)
    dir = -1 - fit in upstream direction   (resulting helix is first element of vecTPar)
    
    mode =  0 - straight line fit
    mode =  1 - starts from known (in the first approximation) helix 
            (first or last, depending on direction).
             Scale up covariance matrix and do the fit
    mode =  2 - start from fully uncertain (except of momentum) helix (for debug only)

References Chi2tot(), PaSetup::Detector(), PaTPar::HasMom(), PaTPar::HitChi2(), PaDetect::Name(), PaEvent::Print(), PaHit::Print(), PaTPar::Print(), Phast::Ref(), PaSetup::Ref(), PaTPar::Update(), and PaDetect::Z().

Referenced by FullKF().

const PaTPar& PaTrack::vTPar ( int i ) const [inline]

Trajectory parameter # i.

In "standard" mDST only parameters 2 exists (first and last measured point).
(In productions of 2006 and earlier only PaTPar in the first measured point was stored)

Warning:: For beam tracks (tracks ending before the target) order or track parameters is reversed, so vTPar(0) are parameters at the point closest to target.

References NTPar().

Referenced by CanBeMuon(), CrossYokeSM2(), Extrap(), Extrapolate(), FieldInteg(), PaPid::LikePid(), PointsHodoscopes(), and PaPid::SecondLike().

float PaTrack::ZFirst ( ) const

Z of the first measured point.

This function returns Z of the first track parameter: vTPar(0)

Warning:: As for beam tracks (tracks ending before the target) order of parameters is reversed, i.e. first track parameters is closest to the target.

float PaTrack::ZLast ( ) const [inline]

Z of the last measured point.

This finction return Z coordinate of the last hitted detectors (corresponding to last bit of HitsFound()).

References Zmax().

Referenced by CanBeMuon(), CrossYokeSM2(), FieldInteg(), and PaVertex::iMuPrim().

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

lib/PaTrack.h
lib/PaTrack.cc
lib/PaTrackFullKF.cc
lib/PaTrackGetSmoothed.cc
lib/PaTrackQuickKF.cc

PaTrack Class Reference

Public Member Functions

Detailed Description

Member Function Documentation