HelicalTrackHit (LCSim 3.1.7 API)

java.lang.Object
- org.lcsim.fit.helicaltrack.HelicalTrackHit

All Implemented Interfaces:

Comparable, TrackerHit

Direct Known Subclasses:

HelicalTrack2DHit, HelicalTrack3DHit, HelicalTrackCross
```
public class HelicalTrackHit
extends Object
implements Comparable, TrackerHit
```
Encapsulate the hit information needed by HelicalTrackFitter. To account for situations where the best estimate of the hit position and covariance matrix are subject to corrections, both nominal and corrected values of these quantities are stored. The nominal and corrected values are initially identical, but the protected methods setCorrectedPosition and setCorrectedCovMatrix can be used to update the corrected values. Currently, this feature is only used for stereo hits, where the hit position and covariance matrix depend on the track direction.

Version:

$Id$

Author:

Richard Partridge

Field Summary

Fields
Modifier and Type	Field and Description
`private BarrelEndcapFlag`	`_beflag`
`private double`	`_chisq`
`private SymmetricMatrix`	`_cov`
`private SymmetricMatrix`	`_covcor`
`private double`	`_dEdx`
`private String`	`_detname`
`private double`	`_dr`
`private double`	`_drphi`
`protected double`	`_eps`
`protected double`	`_epsParallel`
`protected double`	`_epsStereoAngle`
`private int`	`_layer`
`private List<MCParticle>`	`_mcplist`
`private double`	`_phi`
`private double[]`	`_pos`
`private Hep3Vector`	`_poscor`
`private double`	`_r`
`private List<RawTrackerHit>`	`_rawhits`
`private double`	`_time`
`private int`	`_type`
`protected long`	`id`

Constructor Summary

Constructors
Constructor and Description
`HelicalTrackHit()` Create a new instance of
`HelicalTrackHit(Hep3Vector pos, SymmetricMatrix cov, double dEdx, double time, int type, List rawhits, String detname, int layer, BarrelEndcapFlag beflag)` Create a new instance of

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addMCParticle(MCParticle mcp)` Associate an MCParticle with this hit.
`protected void`	`addRawHit(RawTrackerHit rawhit)`
`BarrelEndcapFlag`	`BarrelEndcapFlag()` Return the BarrelEndcapFlag appropriate for this hit
`double`	`chisq()` Return chi^2 penalty for the hit (used by cross hits when one or both of the unmeasured coordinates is beyond its allowed range).
`int`	`compareTo(Object hit2)` Implement comparable interface to allow hits to be sorted by their corrected z coordinate
`String`	`Detector()`
`double`	`dr()` Return the corrected uncertainty in the radial coordinate r
`protected double`	`drcalc(Hep3Vector pos, SymmetricMatrix cov)`
`double`	`drphi()` Return the corrected uncertainty in the azimuthal coordinate r*phi
`protected double`	`drphicalc(Hep3Vector pos, SymmetricMatrix cov)`
`long`	`getCellID()` Get the cell ID.
`SymmetricMatrix`	`getCorrectedCovMatrix()` Return the corrected covariance matrix.
`Hep3Vector`	`getCorrectedPosition()` Return the corrected hit position.
`double[]`	`getCovMatrix()` Return the nominal (uncorrected) covariance matrix.
`double`	`getdEdx()` Return the energy deposit for this hit.
`double`	`getEdepError()` The measured edep error [GeV].
`double`	`getEpsParallel()`
`String`	`getLayerIdentifier()` Return the layer identifier string.
`List<MCParticle>`	`getMCParticles()` Returns a list of MCParticles belonging to this hit.
`double[]`	`getPosition()` Return the nominal (uncorrected) hit position.
`int`	`getQuality()` The quality of the hit.
`List`	`getRawHits()` Return a list of raw hits for this hit.
`double`	`getTime()` Return the time for this hit.
`int`	`getType()` Return the hit type.
`void`	`init(Hep3Vector pos, SymmetricMatrix cov, double dEdx, double time, int type, List rawhits, String detname, int layer, BarrelEndcapFlag beflag)` Initialize the `HelicalTrackHit`.
`int`	`Layer()`
`double`	`phi()` Return the corrected azimuthal coordinate of the hit
`double`	`r()` Return the corrected radius of the hit (i.e., distance from the z axis)
`protected void`	`setChisq(double chisq)` Set the chi^2 penalty for the hit (used by cross hits when one or both of the unmeasured coordinates is beyond its allowed range).
`protected void`	`setCorrectedCovMatrix(SymmetricMatrix covcor)` Set the corrected covariance matrix.
`protected void`	`setCorrectedPosition(Hep3Vector poscor)` Set the corrected hit position.
`void`	`setEpsParallel(double _epsParallel)`
`void`	`setEpsStereoAngle(double _epsStereoAngle)`
`private void`	`setPolarVariables()` Calculate the polar coordinates _r, _phi from the cartesian coordinates _x, _y and cache them in this object since we expect them to be used repeatedly by the track finding code.
`void`	`setPosition(double[] position)` Set the hit position.
`String`	`toString()` Return a string describing the hit.
`double`	`x()` Return the corrected x coordinate of the HelicalTrackHit
`double`	`y()` Return the corrected y coordinate of the HelicalTrackHit
`double`	`z()` Return the corrected z coordinate of the HelicalTrackHit

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - _pos
```
private double[] _pos
```
  - _poscor
```
private Hep3Vector _poscor
```
  - _cov
```
private SymmetricMatrix _cov
```
  - _covcor
```
private SymmetricMatrix _covcor
```
  - _dEdx
```
private double _dEdx
```
  - _time
```
private double _time
```
  - _type
```
private int _type
```
  - _rawhits
```
private List<RawTrackerHit> _rawhits
```
  - _detname
```
private String _detname
```
  - _layer
```
private int _layer
```
  - _beflag
```
private BarrelEndcapFlag _beflag
```
  - _mcplist
```
private List<MCParticle> _mcplist
```
  - _r
```
private double _r
```
  - _phi
```
private double _phi
```
  - _drphi
```
private double _drphi
```
  - _dr
```
private double _dr
```
  - _chisq
```
private double _chisq
```
  - _eps
```
protected double _eps
```
  - _epsParallel
```
protected double _epsParallel
```
  - _epsStereoAngle
```
protected double _epsStereoAngle
```
  - id
```
protected long id
```
- Constructor Detail
  - HelicalTrackHit
```
public HelicalTrackHit()
```
    Create a new instance of
  - HelicalTrackHit
```
public HelicalTrackHit(Hep3Vector pos,
               SymmetricMatrix cov,
               double dEdx,
               double time,
               int type,
               List rawhits,
               String detname,
               int layer,
               BarrelEndcapFlag beflag)
```
    Create a new instance of
- Method Detail
  - init
```
public void init(Hep3Vector pos,
        SymmetricMatrix cov,
        double dEdx,
        double time,
        int type,
        List rawhits,
        String detname,
        int layer,
        BarrelEndcapFlag beflag)
```
    Initialize the HelicalTrackHit.
  - setEpsParallel
```
public void setEpsParallel(double _epsParallel)
```
  - getEpsParallel
```
public double getEpsParallel()
```
  - setEpsStereoAngle
```
public void setEpsStereoAngle(double _epsStereoAngle)
```
  - x
```
public double x()
```
    Return the corrected x coordinate of the HelicalTrackHit
    
    Returns:
    x coordinate
  - y
```
public double y()
```
    Return the corrected y coordinate of the HelicalTrackHit
    
    Returns:
    y coordinate
  - z
```
public double z()
```
    Return the corrected z coordinate of the HelicalTrackHit
    
    Returns:
    z coordinate
  - r
```
public double r()
```
    Return the corrected radius of the hit (i.e., distance from the z axis)
    
    Returns:
    radial coordinate
  - phi
```
public double phi()
```
    Return the corrected azimuthal coordinate of the hit
    
    Returns:
    azimuthal coordinate
  - drphi
```
public double drphi()
```
    Return the corrected uncertainty in the azimuthal coordinate r*phi
    
    Returns:
    uncertainty in r*phi
  - dr
```
public double dr()
```
    Return the corrected uncertainty in the radial coordinate r
    
    Returns:
    uncertainty in r
  - chisq
```
public double chisq()
```
    Return chi^2 penalty for the hit (used by cross hits when one or both of the unmeasured coordinates is beyond its allowed range).
    
    Returns:
    chi^2 penalty
  - BarrelEndcapFlag
```
public BarrelEndcapFlag BarrelEndcapFlag()
```
    Return the BarrelEndcapFlag appropriate for this hit
    
    Returns:
    BarrelEndcapFlag for this hit
  - compareTo
```
public int compareTo(Object hit2)
```
    Implement comparable interface to allow hits to be sorted by their corrected z coordinate
    
    Specified by:
    
    compareTo in interface Comparable
    
    Parameters:
    hit2 - HelicalTrackHit to be compared against this instance
    
    Returns:
    1 if the z for this hit is greater than for hit2
  - addMCParticle
```
public void addMCParticle(MCParticle mcp)
```
    Associate an MCParticle with this hit.
    
    Parameters:
    mcp - MCParticle that is associated with this hit
  - getMCParticles
```
public List<MCParticle> getMCParticles()
```
    Returns a list of MCParticles belonging to this hit. null is returned if no list can be found.
    
    Returns:
    A list of MCParticles, or null if none can be retrieved.
  - getPosition
```
public double[] getPosition()
```
    Return the nominal (uncorrected) hit position.
    
    Specified by:
    
    getPosition in interface TrackerHit
    
    Returns:
    nominal hit position
  - getCorrectedPosition
```
public Hep3Vector getCorrectedPosition()
```
    Return the corrected hit position.
    
    Returns:
    Corrected hit position
  - getCovMatrix
```
public double[] getCovMatrix()
```
    Return the nominal (uncorrected) covariance matrix.
    
    Specified by:
    
    getCovMatrix in interface TrackerHit
    
    Returns:
    nominal covariance matrix
  - getCorrectedCovMatrix
```
public SymmetricMatrix getCorrectedCovMatrix()
```
    Return the corrected covariance matrix.
    
    Returns:
    corrected covariance matrix
  - getdEdx
```
public double getdEdx()
```
    Return the energy deposit for this hit.
    
    Specified by:
    
    getdEdx in interface TrackerHit
    
    Returns:
    energy deposit
  - getTime
```
public double getTime()
```
    Return the time for this hit.
    
    Specified by:
    
    getTime in interface TrackerHit
    
    Returns:
    hit time
  - getType
```
public int getType()
```
    Return the hit type.
    
    Specified by:
    
    getType in interface TrackerHit
    
    Returns:
    hit type
  - getQuality
```
public int getQuality()
```
    Description copied from interface: TrackerHit
    
    The quality of the hit.
    
    Specified by:
    
    getQuality in interface TrackerHit
  - getEdepError
```
public double getEdepError()
```
    Description copied from interface: TrackerHit
    
    The measured edep error [GeV].
    
    Specified by:
    
    getEdepError in interface TrackerHit
  - getRawHits
```
public List getRawHits()
```
    Return a list of raw hits for this hit.
    
    Specified by:
    
    getRawHits in interface TrackerHit
    
    Returns:
    raw hit list
  - Detector
```
public String Detector()
```
  - Layer
```
public int Layer()
```
  - getLayerIdentifier
```
public String getLayerIdentifier()
```
    Return the layer identifier string.
    
    Returns:
    layer identifier
  - toString
```
public String toString()
```
    Return a string describing the hit.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    hit description
  - setPosition
```
public void setPosition(double[] position)
```
    Set the hit position.
    
    Parameters:
    position - : hit position
  - setCorrectedPosition
```
protected void setCorrectedPosition(Hep3Vector poscor)
```
    Set the corrected hit position.
    
    Parameters:
    poscor - corrected hit position
  - setCorrectedCovMatrix
```
protected void setCorrectedCovMatrix(SymmetricMatrix covcor)
```
    Set the corrected covariance matrix.
    
    Parameters:
    covcor - corrected covariance matrix
  - addRawHit
```
protected void addRawHit(RawTrackerHit rawhit)
```
  - setChisq
```
protected void setChisq(double chisq)
```
    Set the chi^2 penalty for the hit (used by cross hits when one or both of the unmeasured coordinates is beyond its allowed range).
    
    Parameters:
    chisq - chi^2 penalty
  - drphicalc
```
protected double drphicalc(Hep3Vector pos,
               SymmetricMatrix cov)
```
  - drcalc
```
protected double drcalc(Hep3Vector pos,
            SymmetricMatrix cov)
```
  - setPolarVariables
```
private void setPolarVariables()
```
    Calculate the polar coordinates _r, _phi from the cartesian coordinates _x, _y and cache them in this object since we expect them to be used repeatedly by the track finding code.
  - getCellID
```
public long getCellID()
```
    Description copied from interface: TrackerHit
    
    Get the cell ID.
    
    Specified by:
    
    getCellID in interface TrackerHit
    
    Returns:
    The cell ID.

Class HelicalTrackHit

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

_pos

_poscor

_cov

_covcor

_dEdx

_time

_type

_rawhits

_detname

_layer

_beflag

_mcplist

_r

_phi

_drphi

_dr

_chisq

_eps

_epsParallel

_epsStereoAngle

id

Constructor Detail

HelicalTrackHit

HelicalTrackHit

Method Detail

init

setEpsParallel

getEpsParallel

setEpsStereoAngle

x

y

z

r

phi

drphi

dr

chisq

BarrelEndcapFlag

compareTo

addMCParticle

getMCParticles

getPosition

getCorrectedPosition

getCovMatrix

getCorrectedCovMatrix

getdEdx

getTime

getType

getQuality

getEdepError

getRawHits

Detector

Layer

getLayerIdentifier

toString

setPosition

setCorrectedPosition

setCorrectedCovMatrix

addRawHit

setChisq

drphicalc

drcalc

setPolarVariables

getCellID