Track finder based on triplets of rows. More...

#include <RowTripletBasedTrackFinderProcessor.h>

Inheritance diagram for marlintpc::RowTripletBasedTrackFinderProcessor:

Public Member Functions
virtual Processor *	newProcessor ()

	RowTripletBasedTrackFinderProcessor ()
	Construct processor. More...

virtual void	init ()
	Initialize processor. More...

virtual void	processRunHeader (EVENT::LCRunHeader *run)

virtual void	processEvent (EVENT::LCEvent *evt)
	Process event. More...

virtual void	check (EVENT::LCEvent *evt)

virtual void	end ()

Protected Attributes
std::string	_inputColName
	Name of the input collection. More...

std::string	_outputColName
	Name of the output collection. More...

double	_bfieldScaleFactor
	scale factor for magnetic field (default: 1.0) More...

double	_distCut
	Coarse cut on XY and Z residuals for triplet preselection. More...

double	_trpCut
	Chi2 cut for triplet definition on XY and Z residuals. More...

double	_posCut
	Chi2 cut for triplet position matching in XY and Z. More...

double	_dirCut
	Chi2 cut for triplet direction matching in XY and Z. More...

double	_segCut
	Chi2/Ndf cut for segment matching (Ndf=4 for B off, 5 for B on) More...

double	_unusedCut
	Chi2 cut for matching unused hits in XY and Z. More...

int	_maxGap
	Cut for (row) distance to segment for matching unused hits in XY and Z. More...

bool	_encodedModuleID
	Module ID is encoded in CellID0. More...

bool	_refAtPCA
	Use Pca as reference point (else 1. hit) More...

Private Member Functions
bool	areNeighbourModules (gear::TPCModule , gear::TPCModule , bool)
	Check if modules are neighbours. More...

Private Attributes
double	_Bzc
	magnetic field strength (Bz*c) More...

std::map< int, std::vector< int > >	_modNeighbours
	neighbour modules More...

double	_Xcenter
	TPC center, X coordinate. More...

double	_Ycenter
	TPC center, Y coordinate. More...

Detailed Description

Track finder based on triplets of rows.

Inspired by H1 pattern recognition by V. Blobel (Univ. Hamburg).

Input are the (position, measurement direction and errors) of the TPC hits and module parameters (offset and extend) from GEAR.

In each module (with hits):

Triplets of hits in adjacent even or odd rows are constructed
Triplets matching in position and direction are connected to segments
Segments with compatible track parameters are merged
Unused hits are added to matching segments

Segments from each module are combined with compatible segments from the corresponding neighbouring modules to build track candidates. As reference point for the track canidates the first hit is used (optional: PCA).

The hits on the track candidates are ordered by row number, no multiple hits in a row are allowed. All matching criteria use chi2 cuts based on the hit measurement errors. The calculation of the measurement (pad) direction in XY uses "module.getLocalPadLayout().getCoordinateType()" to select polar or cartesian pad row geometry.

Parameters

"InputHits":string	The name of the input collection of TPC hits (default: "TPCHits")
"OutputTracks":string	The name of the output collection with the found tracks (default: "TripletTracks")
"BFieldScaleFactor":double	`Optional` parameter, scales magnetic field (map), use 1.0 (default) for field ON or 0.0 for field OFF
"TripletPreSelectionDistCut":double	`Optional` parameter, coarse cut on XY and Z residuals for triplet preselection (default 10.)
"TripletDefinitionChi2Cut":double	`Optional` parameter, Chi2 cut for triplet definition on XY and Z residuals (default 20.)
"TripletPositionMatchingChi2Cut":double	`Optional` parameter, Chi2 cut for triplet position matching in XY and Z (default 20.)
"TripletDirectionMatchingChi2Cut":double	`Optional` parameter, Chi2 cut for triplet direction matching in XY and Z (default 20.)
"SegmentMatchingChi2Cut":double	`Optional` parameter, Chi2/Ndf cut for segment matching (Ndf=4 for B off, 5 for B on) (default 30.)
"UnusedHitMatchingChi2Cut":double	`Optional` parameter, Chi2 cut for matching unused hits in XY and Z (default 20.)
"UnusedHitMaxGapCut:int	`Optional` parameter, maximal (row) gap for matching unused hits in XY and Z (default 4)
"EncodedModuleID":bool	`Optional` parameter, flag for encoding of module ID in CellID0 (default true)
"ReferencePointAtPca":bool	`Optional` parameter, use PCA as reference point, else 1. hit (default false)

Author: C. Kleinwort (130729)

Todo:

definition of module neighbourhood from POLAR module extend ?
better resolve equivalent (indirectly matching) overlapping segments ?

A detailed description is available as lcnote LC-TOOL-2014-004. Changes with respect to this note:

Triplet measurement direction is average of outer hits instead of center hit (, already used for doublets).
Segment fit is iterated as weights depend on track direction (due to radial hit error).

Definition at line 77 of file RowTripletBasedTrackFinderProcessor.h.

Constructor & Destructor Documentation

◆ RowTripletBasedTrackFinderProcessor()

marlintpc::RowTripletBasedTrackFinderProcessor::RowTripletBasedTrackFinderProcessor ( )

Construct processor.

Definition at line 38 of file RowTripletBasedTrackFinderProcessor.cc.

References _bfieldScaleFactor, _dirCut, _distCut, _encodedModuleID, _inputColName, _maxGap, _outputColName, _posCut, _refAtPCA, _segCut, _trpCut, and _unusedCut.

Referenced by newProcessor().

Member Function Documentation

◆ areNeighbourModules()

bool marlintpc::RowTripletBasedTrackFinderProcessor::areNeighbourModules	(	gear::TPCModule *	mod1,
		gear::TPCModule *	mod2,
		bool	cartesian
	)

private

Check if modules are neighbours.

Parameters

[in]	mod1	first module
[in]	mod2	second module
[in]	cartesian	flag for cartesian coordinates

Returns: flag

Todo:: implement non cartesian (=polar) case

Use getModuleExtent to define module center and extension, cut on distance normalized to (projected) extension (squared)

Definition at line 438 of file RowTripletBasedTrackFinderProcessor.cc.

Referenced by init().

◆ check()

void marlintpc::RowTripletBasedTrackFinderProcessor::check ( EVENT::LCEvent * evt )

virtual

Definition at line 422 of file RowTripletBasedTrackFinderProcessor.cc.

Referenced by newProcessor().

◆ end()

void marlintpc::RowTripletBasedTrackFinderProcessor::end ( )

virtual

Definition at line 426 of file RowTripletBasedTrackFinderProcessor.cc.

Referenced by newProcessor().

◆ init()

void marlintpc::RowTripletBasedTrackFinderProcessor::init ( )

virtual

Initialize processor.

Definition at line 76 of file RowTripletBasedTrackFinderProcessor.cc.

References _modNeighbours, _Xcenter, _Ycenter, and areNeighbourModules().

Referenced by newProcessor().

◆ newProcessor()

virtual Processor* marlintpc::RowTripletBasedTrackFinderProcessor::newProcessor ( )

inlinevirtual

Definition at line 80 of file RowTripletBasedTrackFinderProcessor.h.

References check(), end(), init(), processEvent(), processRunHeader(), and RowTripletBasedTrackFinderProcessor().

◆ processEvent()

void marlintpc::RowTripletBasedTrackFinderProcessor::processEvent ( EVENT::LCEvent * evt )

virtual

Process event.

Prepare input: map of modules with maps of rows with vectors of hits
For each module independently build track segments from triplets.

Look for triplets.
Look for segments = triplet chains.
Link segments (in module).
Link unused hits to segments.

Link segments between modules.
Fill output collection.

Definition at line 104 of file RowTripletBasedTrackFinderProcessor.cc.

References _bfieldScaleFactor, _Bzc, _dirCut, _distCut, _encodedModuleID, _inputColName, _maxGap, _modNeighbours, _outputColName, _posCut, _refAtPCA, _segCut, _trpCut, _unusedCut, _Xcenter, _Ycenter, marlintpc::simpleEquiClasses::addIndex(), marlintpc::simpleEquiClasses::addMatch(), marlintpc::simpleEquiClasses::getClasses(), marlintpc::rb_Segment::getNdf(), and marlintpc::rb_Doublet::match().

Referenced by newProcessor().

◆ processRunHeader()

void marlintpc::RowTripletBasedTrackFinderProcessor::processRunHeader ( EVENT::LCRunHeader * run )

virtual

Definition at line 99 of file RowTripletBasedTrackFinderProcessor.cc.

Referenced by newProcessor().

Member Data Documentation

◆ _bfieldScaleFactor

double marlintpc::RowTripletBasedTrackFinderProcessor::_bfieldScaleFactor

protected

scale factor for magnetic field (default: 1.0)

Definition at line 100 of file RowTripletBasedTrackFinderProcessor.h.

Referenced by processEvent(), and RowTripletBasedTrackFinderProcessor().

◆ _Bzc

double marlintpc::RowTripletBasedTrackFinderProcessor::_Bzc

private

magnetic field strength (Bz*c)

Definition at line 113 of file RowTripletBasedTrackFinderProcessor.h.

Referenced by processEvent().

◆ _dirCut

double marlintpc::RowTripletBasedTrackFinderProcessor::_dirCut

protected

Chi2 cut for triplet direction matching in XY and Z.

Definition at line 104 of file RowTripletBasedTrackFinderProcessor.h.

Referenced by processEvent(), and RowTripletBasedTrackFinderProcessor().

◆ _distCut

double marlintpc::RowTripletBasedTrackFinderProcessor::_distCut

protected

Coarse cut on XY and Z residuals for triplet preselection.

Definition at line 101 of file RowTripletBasedTrackFinderProcessor.h.

Referenced by processEvent(), and RowTripletBasedTrackFinderProcessor().

◆ _encodedModuleID

bool marlintpc::RowTripletBasedTrackFinderProcessor::_encodedModuleID

protected

Module ID is encoded in CellID0.

Definition at line 108 of file RowTripletBasedTrackFinderProcessor.h.

Referenced by processEvent(), and RowTripletBasedTrackFinderProcessor().

◆ _inputColName

std::string marlintpc::RowTripletBasedTrackFinderProcessor::_inputColName

protected

Name of the input collection.

Definition at line 98 of file RowTripletBasedTrackFinderProcessor.h.

Referenced by processEvent(), and RowTripletBasedTrackFinderProcessor().

◆ _maxGap

int marlintpc::RowTripletBasedTrackFinderProcessor::_maxGap

protected

Cut for (row) distance to segment for matching unused hits in XY and Z.

Definition at line 107 of file RowTripletBasedTrackFinderProcessor.h.

Referenced by processEvent(), and RowTripletBasedTrackFinderProcessor().

◆ _modNeighbours

std::map<int, std::vector<int> > marlintpc::RowTripletBasedTrackFinderProcessor::_modNeighbours

private

neighbour modules

Definition at line 114 of file RowTripletBasedTrackFinderProcessor.h.

Referenced by init(), and processEvent().

◆ _outputColName

std::string marlintpc::RowTripletBasedTrackFinderProcessor::_outputColName

protected

Name of the output collection.

Definition at line 99 of file RowTripletBasedTrackFinderProcessor.h.

Referenced by processEvent(), and RowTripletBasedTrackFinderProcessor().

◆ _posCut

double marlintpc::RowTripletBasedTrackFinderProcessor::_posCut

protected

Chi2 cut for triplet position matching in XY and Z.

Definition at line 103 of file RowTripletBasedTrackFinderProcessor.h.

Referenced by processEvent(), and RowTripletBasedTrackFinderProcessor().

◆ _refAtPCA

bool marlintpc::RowTripletBasedTrackFinderProcessor::_refAtPCA

protected

Use Pca as reference point (else 1. hit)

Definition at line 109 of file RowTripletBasedTrackFinderProcessor.h.

Referenced by processEvent(), and RowTripletBasedTrackFinderProcessor().

◆ _segCut

double marlintpc::RowTripletBasedTrackFinderProcessor::_segCut

protected

Chi2/Ndf cut for segment matching (Ndf=4 for B off, 5 for B on)

Definition at line 105 of file RowTripletBasedTrackFinderProcessor.h.

Referenced by processEvent(), and RowTripletBasedTrackFinderProcessor().

◆ _trpCut

double marlintpc::RowTripletBasedTrackFinderProcessor::_trpCut

protected

Chi2 cut for triplet definition on XY and Z residuals.

Definition at line 102 of file RowTripletBasedTrackFinderProcessor.h.

Referenced by processEvent(), and RowTripletBasedTrackFinderProcessor().

◆ _unusedCut

double marlintpc::RowTripletBasedTrackFinderProcessor::_unusedCut

protected

Chi2 cut for matching unused hits in XY and Z.

Definition at line 106 of file RowTripletBasedTrackFinderProcessor.h.

Referenced by processEvent(), and RowTripletBasedTrackFinderProcessor().

◆ _Xcenter

double marlintpc::RowTripletBasedTrackFinderProcessor::_Xcenter

private

TPC center, X coordinate.

Definition at line 115 of file RowTripletBasedTrackFinderProcessor.h.

Referenced by init(), and processEvent().

◆ _Ycenter

double marlintpc::RowTripletBasedTrackFinderProcessor::_Ycenter

private

TPC center, Y coordinate.

Definition at line 116 of file RowTripletBasedTrackFinderProcessor.h.

Referenced by init(), and processEvent().

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

Public Member Functions

Protected Attributes

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ RowTripletBasedTrackFinderProcessor()

Member Function Documentation

◆ areNeighbourModules()

◆ check()

◆ end()

◆ init()

◆ newProcessor()

◆ processEvent()

◆ processRunHeader()

Member Data Documentation

◆ _bfieldScaleFactor

◆ _Bzc

◆ _dirCut

◆ _distCut

◆ _encodedModuleID

◆ _inputColName

◆ _maxGap

◆ _modNeighbours

◆ _outputColName

◆ _posCut

◆ _refAtPCA

◆ _segCut

◆ _trpCut

◆ _unusedCut

◆ _Xcenter

◆ _Ycenter