org.lcsim.fit.helicaltrack

Class StereoHitMaker

java.lang.Object

org.lcsim.fit.helicaltrack.StereoHitMaker

public class StereoHitMaker
extends Object

This class forms stereo hits (HelicalTrackCross) from pairs of hits in parallel sensor layers.

Version:

$Id: StereoHitMaker.java,v 1.14 2013/02/09 00:41:09 omoreno Exp $

Author:

Richard Partridge

Field Summary

Fields

Modifier and Type	Field and Description
private double	_epsParallel
private double	_epsStereoAngle
private double	_maxsep
private double	_tolerance
(package private) static boolean	debug

Constructor Summary

Constructors

Constructor and Description
StereoHitMaker() Creates a new instance of StereoHitMaker with default parameters: MaxSeparation = 10 mm Tolerance = 2
StereoHitMaker(double tolerance, double maxsep) Fully qualified constructor for StereoHitMaker.

Method Summary

Methods

Modifier and Type	Method and Description
private boolean	CheckCross(HelicalTrackStrip strip1, HelicalTrackStrip strip2) Check a pair of hits to see if we can make a valid cross hit.
private HelicalTrackCross	MakeHit(HelicalTrackStrip strip1, HelicalTrackStrip strip2) Try to form a cross hit from two HelicalTrackStrips.
List<HelicalTrackCross>	MakeHits(List<HelicalTrackStrip> stripcol) Create cross hits from a list of HelicalTrackStrip hits.
List<HelicalTrackCross>	MakeHits(List<HelicalTrackStrip> slist1, List<HelicalTrackStrip> slist2) Create cross hits from two lists of HelicalTrackStrip hits.
void	setEpsParallel(double _epsParallel)
void	setEpsStereoAngle(double _epsStereoAngle)
void	setMaxSeparation(double maxsep) Set the maximum separation between sensor planes in the direction normal to the sensor.
void	setTolerance(double tolerance) Set the tolerance parameter, which is a dimensionless parameter that characterizes the maximum angle between a track and the sensor for high efficiency.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

debug

static final boolean debug

See Also:

Constant Field Values

_tolerance

private double _tolerance

_maxsep

private double _maxsep

_epsParallel

private double _epsParallel

_epsStereoAngle

private double _epsStereoAngle

Constructor Detail

StereoHitMaker

public StereoHitMaker()

Creates a new instance of StereoHitMaker with default parameters: MaxSeparation = 10 mm Tolerance = 2

StereoHitMaker

public StereoHitMaker(double tolerance,
              double maxsep)

Fully qualified constructor for StereoHitMaker. The tolerance is a dimensionless parameter characterizes the maximum angle between a track and the sensor for high efficiency. A tolerance near unity will allow hits to be found even for steeply inclined tracks. The maximum separation sets the maximum distance between sensor planes when forming paired hits.

Parameters:

tolerance - dimensionless tolerance parameter

maxsep - maximum separation between sensor planes (units are mm)

Method Detail

MakeHits

public List<HelicalTrackCross> MakeHits(List<HelicalTrackStrip> slist1,
                               List<HelicalTrackStrip> slist2)

Create cross hits from two lists of HelicalTrackStrip hits. The cross hits are found by making pairs of hits, taking one hit from each list, that are compatible with forming crosses.

Parameters:

slist1 - list of HelicalTrackStrips in first sensor plane

slist2 - list of HelicalTrackStrips in second sensor plane

Returns:

list of HelicalTrackCross hits

MakeHits

public List<HelicalTrackCross> MakeHits(List<HelicalTrackStrip> stripcol)

Create cross hits from a list of HelicalTrackStrip hits. Each pair of hits is checked for consistency with forming a cross hit. Pairs are only formed from strips with the same detector name, layer number, and BarrelEndcapFlag.

Parameters:

stripcol - list of HelicalTrackStrips

Returns:

list of HelicalTrackCross hits

setMaxSeparation

public void setMaxSeparation(double maxsep)

Set the maximum separation between sensor planes in the direction normal to the sensor.

Parameters:

maxsep - maximum sensor seperation (units are mm)

setTolerance

public void setTolerance(double tolerance)

Set the tolerance parameter, which is a dimensionless parameter that characterizes the maximum angle between a track and the sensor for high efficiency. A tolerance near unity will allow hits to be found even for steeply inclined tracks.

Parameters:

tolerance - tolerance parameter

MakeHit

private HelicalTrackCross MakeHit(HelicalTrackStrip strip1,
                        HelicalTrackStrip strip2)

Try to form a cross hit from two HelicalTrackStrips. Returns null if these two strips don't form a valid cross.

Parameters:

strip1 - first strip

strip2 - second strip

Returns:

cross hit (or null if a valid cross hit cannot be made)

CheckCross

private boolean CheckCross(HelicalTrackStrip strip1,
                 HelicalTrackStrip strip2)

Check a pair of hits to see if we can make a valid cross hit. Checks include requiring the sensors to be parallel with a separation less than the maximum separation, that the two strips are not collinear, and that the intersection assuming a normal trajectory gives unmeasured coordinates that are consistent with the strip limits (or if outside the strip limits, are within the allowed tolerance).

Parameters:

strip1 - first strip

strip2 - second strip

Returns:

setEpsParallel

public void setEpsParallel(double _epsParallel)

setEpsStereoAngle

public void setEpsStereoAngle(double _epsStereoAngle)