Track

All Superinterfaces:

Cloneable, LCObject

All Known Implementing Classes:

ITrack
```
public interface Track
extends LCObject
```
The LCIO track class. The helix parameterization follows that of the L3 experiment at LEP. A detailed description of the track parameters is given in the LC-Note LC-DET-2006-004 "Track Parameters in LCIO" (pdf).

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`float`	`getChi2()` Chi^2 of the track fit.
`TrackState`	`getClosestTrackState(float x, float y, float z)` Returns track state closest to the given point.
`float[]`	`getCovMatrix()` Covariance matrix of the track parameters.
`float`	`getD0()` Impact paramter of the track in (r-phi).
`float`	`getdEdx()` dEdx of the track.
`float`	`getdEdxError()` Error of dEdx.
`int`	`getNdf()` Number of degrees of freedom of the track fit.
`float`	`getOmega()` Omega is the signed curvature of the track in [1/mm].
`float`	`getPhi()` Phi of the track at the reference point.
`float`	`getRadiusOfInnermostHit()` The radius of the innermost hit that has been used in the track fit.
`float[]`	`getReferencePoint()` Reference point of the track parameters.
`int[]`	`getSubdetectorHitNumbers()` A vector that holds the number of hits in particular subdetectors.
`float`	`getTanLambda()` Lambda is the dip angle of the track in r-z at the reference point.
`List`	`getTrackerHits()` Optionaly ( check/set flag(LCIO::TRBIT_HITS)==1) return the hits that have been used to create this track.
`List`	`getTracks()` The tracks that have been combined to this track.
`TrackState`	`getTrackState(int location)` Returns track state for the given location - or NULL if not found.
`List`	`getTrackStates()` Returns track states associtated to this track.
`int`	`getType()` Flagword that defines the type of track.
`float`	`getZ0()` Impact paramter of the track in (r-z).

- Method Detail
  - getType
```
int getType()
```
    Flagword that defines the type of track. Bits 0-15 can be used to denote the subdetectors that have contributed hits used in the track fit. For the definition of the bits check/Set the collection variables TrackTypeBitNames and TrackTypeBitIndices.
    Bits 16-31 are used internally.
  - getD0
```
float getD0()
```
    Impact paramter of the track in (r-phi). Information is stored in the first TrackState of this Track, @see TrackState.
  - getPhi
```
float getPhi()
```
    Phi of the track at the reference point. @see getReferencePoint Information is stored in the first TrackState of this Track, @see TrackState.
  - getOmega
```
float getOmega()
```
    Omega is the signed curvature of the track in [1/mm]. The sign is that of the particle's charge. Information is stored in the first TrackState of this Track, @see TrackState.
  - getZ0
```
float getZ0()
```
    Impact paramter of the track in (r-z). Information is stored in the first TrackState of this Track, @see TrackState.
  - getTanLambda
```
float getTanLambda()
```
    Lambda is the dip angle of the track in r-z at the reference point. @see getReferencePoint Information is stored in the first TrackState of this Track, @see TrackState.
  - getCovMatrix
```
float[] getCovMatrix()
```
    Covariance matrix of the track parameters. Stored as lower triangle matrix where the order of parameters is: d0, phi, omega, z0, tan(lambda). So we have cov(d0,d0), cov( phi, d0 ), cov( phi, phi), ... Information is stored in the first TrackState of this Track, @see TrackState.
  - getReferencePoint
```
float[] getReferencePoint()
```
    Reference point of the track parameters. The default for the reference point is the point of closest approach. Information is stored in the first TrackState of this Track, @see TrackState.
  - getChi2
```
float getChi2()
```
    Chi^2 of the track fit.
  - getNdf
```
int getNdf()
```
    Number of degrees of freedom of the track fit.
  - getdEdx
```
float getdEdx()
```
    dEdx of the track.
  - getdEdxError
```
float getdEdxError()
```
    Error of dEdx.
  - getRadiusOfInnermostHit
```
float getRadiusOfInnermostHit()
```
    The radius of the innermost hit that has been used in the track fit. Helps to detect V0 tracks with small impact paramters or heavy mesons. To be used as convenient information or if hits are not stored in the data set, e.g. DST or FastMC.
  - getSubdetectorHitNumbers
```
int[] getSubdetectorHitNumbers()
```
    A vector that holds the number of hits in particular subdetectors. The mapping of indices to subdetectors is implementation dependent. To be used as convenient information or if hits are not stored in the data set, e.g. DST or FastMC. Check/set collection variable TrackSubdetectorNames for decoding the indices.
  - getTracks
```
List getTracks()
```
    The tracks that have been combined to this track.
  - getTrackStates
```
List getTrackStates()
```
    Returns track states associtated to this track. @see TrackState.
  - getClosestTrackState
```
TrackState getClosestTrackState(float x,
                                float y,
                                float z)
```
    Returns track state closest to the given point. @see TrackState.
  - getTrackState
```
TrackState getTrackState(int location)
```
    Returns track state for the given location - or NULL if not found. @see TrackState. location can be: TrackState::AtIP, TrackState::AtFirstHit, TrackState::AtLastHit, TrackState::AtCalorimeter, TrackState::AtVertex, TrackState::AtOther
  - getTrackerHits
```
List getTrackerHits()
```
    Optionaly ( check/set flag(LCIO::TRBIT_HITS)==1) return the hits that have been used to create this track.

Interface Track

Method Summary

Method Detail

getType

getD0

getPhi

getOmega

getZ0

getTanLambda

getCovMatrix

getReferencePoint

getChi2

getNdf

getdEdx

getdEdxError

getRadiusOfInnermostHit

getSubdetectorHitNumbers

getTracks

getTrackStates

getClosestTrackState

getTrackState

getTrackerHits