Track finder based on Fast Hough Transformation. More...

#include <RowBasedFastHoughTransformationProcessor.h>

Inheritance diagram for marlintpc::RowBasedFastHoughTransformationProcessor:

Public Member Functions
virtual Processor *	newProcessor ()

	RowBasedFastHoughTransformationProcessor ()
	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...

bool	_useXY
	Use XY (anode plane) measurement. More...

bool	_useXZ
	Use XZ (drift time) measurement. More...

double	_centerXY
	Center of XY (anode plane) measurement. More...

double	_rangeXY
	Range of XY (anode plane) measurement. More...

double	_centerXZ
	Center of XZ (drift time) measurement. More...

double	_rangeXZ
	Range of XZ (drift time) measurement. More...

int	_minRow
	Minimal number of (correlated) rows. More...

float	_fracRow
	Relative minimum cube content. More...

int	_maxRowDiff
	Row correation parameter. More...

int	_maxCube
	Maximum number of (hyper) cubes to check. More...

int	_minLevel
	Minimum number of (hyper) cubes splittings. More...

int	_maxLevel
	Maximum number of (hyper) cubes splittings. More...

float	_effCut
	Minimum hit density (hits/tracklength) More...

float	_purCut
	Maximum hit density (hits/tracklength) More...

int	_maxHitsPerRow
	Maximum number hits per row. 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...

bool	_timePixFlag
	Is timepix data. More...

Private Attributes
int	_scaleBits
	number of scale bits (2^(_scaleBits) = 1.0) More...

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

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

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

Detailed Description

Track finder based on Fast Hough Transformation.

Fast Hough transformation to construct tracks from space points.

The average track direction is in (local) X direction. The measured coordinates have to be shifted and rescaled to: X->u in [-1, +1], Y,Z -> v,w in [-0.5, 0.5]. The resolution in v and w should be comparable. The track projections v(u), w(u) are parametrized by series of Legendre polynomials L_i, in the (XY) bending plane up to order 2 and in the (XZ) plane with order 1.:

v(u) = a_0 * L_0(u) + a_1 * L_1(u) (+ a_2 *L_2(u))
w(u) = b_0 * L_0(u) + b_1 * L_1(u)
with L_0(u) = 1., L_1(u) = u, L_2(u) = 1.5*u*u - 0.5

The track parameters a_i, b_i are in [-0.5, +0.5] (the initial hypercube). Each space point defines 2 hyperplanes (v(u)-v_meas=0, w(u)-w_meas=0) in the 5 (or 4) dimensional parameter space (a_i, b_i) with normal vectors (L_i(u), 0.) and (0., L_i(u)). The unit normal vector is used to calculate the distance of a hyperplane to the center of a hypercube. They intersect if the absolute value of the distance times the largest component of the unit normal vector is smaller than 0.5. The root cube is recursivly split for each dimension in two child cubes. Only childs containing a minimum number of rows are considered further until the hit density in a cube is compatible with a single track. The search stops with the first found track candidate.

Extended for timepix data (allow multiple hits per row).

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: "FHTTracks")
"CenterXYMeasurement":double	Center of XY (anode plane) measurement (default 60.)
"RangeXYMeasurement":double	Range of XY (anode plane) measurement (default 200.)
"CenterXZMeasurement":double	Center of XY (drift time) measurement (default 300.)
"RangeXZMeasurement":double	Range of XY (drift time) measurement (default 600.)
"BFieldScaleFactor":double	`Optional` parameter, scales magnetic field (map), use 1.0 (default) for field ON or 0.0 for field OFF
"UseXYMeasurement":bool	`Optional` parameter, flag for using XY (anode plane) measurement (default true)
"UseXZMeasurement":bool	`Optional` parameter, flag for using XZ (drift time) measurement (default true)
"MinimumRows":int	`Optional` parameter, minimal number of (correlated) rows (default 8)
"MaximumRowDifference":int	`Optional` parameter, row correation parameter (max. distance of correlated rows) (default 1)
"FractionOfRows":float	`Optional` parameter, relative minimum cube content (rows >= fraction * (correlated) rows) (default 0.8)
"MaximumCubes":int	`Optional` parameter, maximum number of (hyper) cubes to check (default 250)
"MinimumLevel":int	`Optional` parameter, minimum number of (hyper) cubes splittings (default 5)
"MaximumLevel":int	`Optional` parameter, maximum number of (hyper) cubes splittings (default 8)
"EfficienyCut":float	`Optional` parameter, minimum hit density (hits/tracklength) (default 0.8)
"PurityCut":float	`Optional` parameter, maximum hit density (hits/tracklength) (default 1.1)
"MaxHitsPerRow":int	`Optional` parameter, mximum number of hits per row (default 1)
"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)
"TimePixFlag":bool	`Optional` parameter, is timepix data(default false)

Author: C. Kleinwort (140205)

Todo:

(average) track direction different from X direction ?
hit cleaning for segment creation ?
replace hard coded radial row number for timepix data ?

A detailed description is available as lcnote LC-TOOL-2014-006.

Definition at line 92 of file RowBasedFastHoughTransformationProcessor.h.

Constructor & Destructor Documentation

◆ RowBasedFastHoughTransformationProcessor()

marlintpc::RowBasedFastHoughTransformationProcessor::RowBasedFastHoughTransformationProcessor ( )

Construct processor.

Definition at line 42 of file RowBasedFastHoughTransformationProcessor.cc.

References _bfieldScaleFactor, _centerXY, _centerXZ, _effCut, _encodedModuleID, _fracRow, _inputColName, _maxCube, _maxGap, _maxHitsPerRow, _maxLevel, _maxRowDiff, _minLevel, _minRow, _outputColName, _purCut, _rangeXY, _rangeXZ, _refAtPCA, _timePixFlag, _unusedCut, _useXY, and _useXZ.

Referenced by newProcessor().

Member Function Documentation

◆ check()

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

virtual

Definition at line 408 of file RowBasedFastHoughTransformationProcessor.cc.

Referenced by newProcessor().

◆ end()

void marlintpc::RowBasedFastHoughTransformationProcessor::end ( )

virtual

Definition at line 412 of file RowBasedFastHoughTransformationProcessor.cc.

Referenced by newProcessor().

◆ init()

void marlintpc::RowBasedFastHoughTransformationProcessor::init ( )

virtual

Initialize processor.

Definition at line 97 of file RowBasedFastHoughTransformationProcessor.cc.

Referenced by newProcessor().

◆ newProcessor()

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

inlinevirtual

Definition at line 95 of file RowBasedFastHoughTransformationProcessor.h.

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

◆ processEvent()

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

virtual

Process event.

Prepare input: map of rows with vectors of hits
While sufficient input (unused (correlated) rows)

From unused hits get x range and number of (correlated) rows (row <= lastRow + _maxRowDiff)
Build hyperplanes, root cube entries (distances)
Subdivide root cube
Process candidate

Fill output collection.

Definition at line 107 of file RowBasedFastHoughTransformationProcessor.cc.

References _bfieldScaleFactor, _Bzc, _centerXY, _centerXZ, _effCut, _encodedModuleID, _fracRow, _inputColName, _maxCube, _maxGap, _maxHitsPerRow, _maxLevel, _maxRowDiff, _minLevel, _minRow, _outputColName, _purCut, _rangeXY, _rangeXZ, _refAtPCA, _scaleBits, _timePixFlag, _unusedCut, _useXY, _useXZ, _Xcenter, _Ycenter, marlintpc::rb_Segment::addHit(), marlintpc::rb_HyperCube::divide(), marlintpc::rb_Segment::fillRowMap(), marlintpc::rb_Segment::getFirstRow(), marlintpc::rb_Segment::getHitList(), marlintpc::rb_Segment::getLastRow(), marlintpc::rb_Segment::getNdf(), and marlintpc::rb_Segment::match().

Referenced by newProcessor().

◆ processRunHeader()

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

virtual

Definition at line 102 of file RowBasedFastHoughTransformationProcessor.cc.

Referenced by newProcessor().

Member Data Documentation

◆ _bfieldScaleFactor

double marlintpc::RowBasedFastHoughTransformationProcessor::_bfieldScaleFactor

protected

scale factor for magnetic field (default: 1.0)

Definition at line 115 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _Bzc

double marlintpc::RowBasedFastHoughTransformationProcessor::_Bzc

private

magnetic field strength (Bz*c)

Definition at line 139 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent().

◆ _centerXY

double marlintpc::RowBasedFastHoughTransformationProcessor::_centerXY

protected

Center of XY (anode plane) measurement.

Definition at line 118 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _centerXZ

double marlintpc::RowBasedFastHoughTransformationProcessor::_centerXZ

protected

Center of XZ (drift time) measurement.

Definition at line 120 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _effCut

float marlintpc::RowBasedFastHoughTransformationProcessor::_effCut

protected

Minimum hit density (hits/tracklength)

Definition at line 128 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _encodedModuleID

bool marlintpc::RowBasedFastHoughTransformationProcessor::_encodedModuleID

protected

Module ID is encoded in CellID0.

Definition at line 133 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _fracRow

float marlintpc::RowBasedFastHoughTransformationProcessor::_fracRow

protected

Relative minimum cube content.

Definition at line 123 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _inputColName

std::string marlintpc::RowBasedFastHoughTransformationProcessor::_inputColName

protected

Name of the input collection.

Definition at line 113 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _maxCube

int marlintpc::RowBasedFastHoughTransformationProcessor::_maxCube

protected

Maximum number of (hyper) cubes to check.

Definition at line 125 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _maxGap

int marlintpc::RowBasedFastHoughTransformationProcessor::_maxGap

protected

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

Definition at line 132 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _maxHitsPerRow

int marlintpc::RowBasedFastHoughTransformationProcessor::_maxHitsPerRow

protected

Maximum number hits per row.

Definition at line 130 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _maxLevel

int marlintpc::RowBasedFastHoughTransformationProcessor::_maxLevel

protected

Maximum number of (hyper) cubes splittings.

Definition at line 127 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _maxRowDiff

int marlintpc::RowBasedFastHoughTransformationProcessor::_maxRowDiff

protected

Row correation parameter.

Definition at line 124 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _minLevel

int marlintpc::RowBasedFastHoughTransformationProcessor::_minLevel

protected

Minimum number of (hyper) cubes splittings.

Definition at line 126 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _minRow

int marlintpc::RowBasedFastHoughTransformationProcessor::_minRow

protected

Minimal number of (correlated) rows.

Definition at line 122 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _outputColName

std::string marlintpc::RowBasedFastHoughTransformationProcessor::_outputColName

protected

Name of the output collection.

Definition at line 114 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _purCut

float marlintpc::RowBasedFastHoughTransformationProcessor::_purCut

protected

Maximum hit density (hits/tracklength)

Definition at line 129 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _rangeXY

double marlintpc::RowBasedFastHoughTransformationProcessor::_rangeXY

protected

Range of XY (anode plane) measurement.

Definition at line 119 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _rangeXZ

double marlintpc::RowBasedFastHoughTransformationProcessor::_rangeXZ

protected

Range of XZ (drift time) measurement.

Definition at line 121 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _refAtPCA

bool marlintpc::RowBasedFastHoughTransformationProcessor::_refAtPCA

protected

Use Pca as reference point (else 1. hit)

Definition at line 134 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _scaleBits

int marlintpc::RowBasedFastHoughTransformationProcessor::_scaleBits

private

number of scale bits (2^(_scaleBits) = 1.0)

Definition at line 138 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent().

◆ _timePixFlag

bool marlintpc::RowBasedFastHoughTransformationProcessor::_timePixFlag

protected

Is timepix data.

Definition at line 135 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _unusedCut

double marlintpc::RowBasedFastHoughTransformationProcessor::_unusedCut

protected

Chi2 cut for matching unused hits in XY and Z.

Definition at line 131 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _useXY

bool marlintpc::RowBasedFastHoughTransformationProcessor::_useXY

protected

Use XY (anode plane) measurement.

Definition at line 116 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _useXZ

bool marlintpc::RowBasedFastHoughTransformationProcessor::_useXZ

protected

Use XZ (drift time) measurement.

Definition at line 117 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent(), and RowBasedFastHoughTransformationProcessor().

◆ _Xcenter

double marlintpc::RowBasedFastHoughTransformationProcessor::_Xcenter

private

TPC center, X coordinate.

Definition at line 140 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent().

◆ _Ycenter

double marlintpc::RowBasedFastHoughTransformationProcessor::_Ycenter

private

TPC center, Y coordinate.

Definition at line 141 of file RowBasedFastHoughTransformationProcessor.h.

Referenced by processEvent().

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

Public Member Functions

Protected Attributes

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ RowBasedFastHoughTransformationProcessor()

Member Function Documentation

◆ check()

◆ end()

◆ init()

◆ newProcessor()

◆ processEvent()

◆ processRunHeader()

Member Data Documentation

◆ _bfieldScaleFactor

◆ _Bzc

◆ _centerXY

◆ _centerXZ

◆ _effCut

◆ _encodedModuleID

◆ _fracRow

◆ _inputColName

◆ _maxCube

◆ _maxGap

◆ _maxHitsPerRow

◆ _maxLevel

◆ _maxRowDiff

◆ _minLevel

◆ _minRow

◆ _outputColName

◆ _purCut

◆ _rangeXY

◆ _rangeXZ

◆ _refAtPCA

◆ _scaleBits

◆ _timePixFlag

◆ _unusedCut

◆ _useXY

◆ _useXZ

◆ _Xcenter

◆ _Ycenter