Simple Helix. More...

#include <SimpleHelixTrackModel.h>

Public Member Functions
	simpleHelix (const double, const double, const double, const double, const double, const double *, const double)
	Constructor. More...

	simpleHelix (const double , const double , const double)
	Constructor. More...

void	dump () const
	Dump helix. More...

double	getArcLengthXY (const double *) const
	Get (2D) arc length for given point. More...

void	getZSDirection (double *) const
	Get ZS direction (cosLambda, sinLambda). More...

void	getPosAtArcLength (const double, double *) const
	Get position (on helix) at arc length. More...

bool	getExpectedPlanePos (const double *, const double, double &, double &, double &, double &, double &) const
	Get expected position (and direction) in plane. More...

TMatrixD	analyticalHelixJacobian (const double, const double) const
	Get analytical helix propagator (in constant solenoidal magnetic field) More...

TMatrixD	simplifiedHelixJacobian (const double, const double) const
	Get simplified helix propagator (in constant solenoidal magnetic field) More...

TMatrixD	curvilinearToPerigeeJacobian () const
	Get transformation from curivilinear to perigee track parameters (at reference point) More...

TMatrixD	perigeeToILDJacobian () const
	Get transformation from perigee to L3/ILD track parameters (at reference point) More...

TMatrixD	perigeeToLCIOJacobian () const
	Get transformation from helix to LCIO track parameters (at reference point) More...

TMatrixD	helixToLCIOJacobian () const
	Get transformation from helix to LCIO track parameters (at reference point) More...

void	moveTo (const double, const double, const double, double *)
	Change reference point. More...

void	getStateAt (const double, const double, const double, TMatrixDSym &, TVectorD &, TMatrixDSym &)
	Get state (parameters, covariance matrix) at point. More...

Protected Attributes
const double	_xref
	X of reference point. More...

const double	_yref
	Y of reference point. More...

const double	_zref
	Z of reference point. More...

const double	_bzc
	Z component of magnetic field (*c) More...

const double	_rinv
	1/R More...

const double	_phi0
	flight direction at point of closest approach (in XY) More...

const double	_dca
	distance of closest approach in (XY) More...

const double	_dzds
	dZ/ds More...

const double	_z0
	Z position at distance of closest approach. More...

const double	_xRelCenter
	XY circle parameter: X position of center / R. More...

const double	_yRelCenter
	XY circle parameter: Y position of center / R. More...

const double	_eps
	cut off for straight line approximation (\|relevent scale / R\| < _eps) More...

Detailed Description

Simple Helix.

Utilities for simple helix track model build from perigee parameters, assuming constant magnetic field in Z-direction.

Propagation and transformation jacobians according to Strandlie & Wittek (NIM A 566(2006) 687-698)

Author: C. Kleinwort, DESY (130801)

Definition at line 22 of file SimpleHelixTrackModel.h.

Constructor & Destructor Documentation

◆ simpleHelix() [1/2]

marlintpc::simpleHelix::simpleHelix	(	const double	rinv,
		const double	phi0,
		const double	dca,
		const double	dzds,
		const double	z0,
		const double *	refPoint,
		const double	Bzc
	)

Constructor.

Definition at line 125 of file SimpleHelixTrackModel.cc.

◆ simpleHelix() [2/2]

marlintpc::simpleHelix::simpleHelix	(	const double *	parameters,
		const double *	refPoint,
		const double	Bzc
	)

Constructor.

Definition at line 132 of file SimpleHelixTrackModel.cc.

Member Function Documentation

◆ analyticalHelixJacobian()

TMatrixD marlintpc::simpleHelix::analyticalHelixJacobian	(	const double	phi1,
		const double	ds
	)		const

Get analytical helix propagator (in constant solenoidal magnetic field)

For curvilinear track parameters (q/p,lambda,phi,x_t,y_t).

Parameters

[in]	phi1	azimutal direction at start point
[in]	ds	(3D) arc length to end point

Returns: (5*5) propagation matrix

Definition at line 255 of file SimpleHelixTrackModel.cc.

References _bzc, _dzds, _rinv, and marlintpc::localHelixAnalyticalJacobian().

Referenced by marlintpc::SimpleHelixGeneralBrokenLineInterfaceProcessor::processEvent().

◆ curvilinearToPerigeeJacobian()

TMatrixD marlintpc::simpleHelix::curvilinearToPerigeeJacobian ( ) const

Get transformation from curivilinear to perigee track parameters (at reference point)

(q/p, lambda, phi, x_t, y_t) -> (kappa, theta, phi, epsilon, z_p)

Returns: (5*5) transformation matrix

Definition at line 294 of file SimpleHelixTrackModel.cc.

References _bzc, _dzds, _phi0, and _rinv.

Referenced by marlintpc::SimpleHelixGeneralBrokenLineInterfaceProcessor::processEvent(), and marlintpc::StepWiseHelixGeneralBrokenLineInterfaceProcessor::processEvent().

◆ dump()

void marlintpc::simpleHelix::dump ( ) const

Dump helix.

Definition at line 139 of file SimpleHelixTrackModel.cc.

References _dca, _dzds, _phi0, _rinv, _xref, _xRelCenter, _yref, _yRelCenter, _z0, and _zref.

◆ getArcLengthXY()

double marlintpc::simpleHelix::getArcLengthXY ( const double * position ) const

Get (2D) arc length for given point.

Arc length from dca to point on circle on intersection with line from circle center to given point

Parameters

[in] position (XY) Position

Returns: (2D) arc length from dca to point on circle

Definition at line 153 of file SimpleHelixTrackModel.cc.

References _eps, _phi0, _rinv, _xref, _xRelCenter, _yref, and _yRelCenter.

Referenced by marlintpc::pb_Seed::_fitSeed(), marlintpc::rb_Segment::fitSegment(), marlintpc::SimpleHelixGeneralBrokenLineInterfaceProcessor::processEvent(), marlintpc::StepWiseHelixGeneralBrokenLineInterfaceProcessor::processEvent(), and marlintpc::tp_PixelSegment::tp_PixelSegment().

◆ getExpectedPlanePos()

bool marlintpc::simpleHelix::getExpectedPlanePos	(	const double *	point,
		const double	measPhi,
		double &	xyPos,
		double &	zPos,
		double &	sArc,
		double &	phi,
		double &	lambda
	)		const

Get expected position (and direction) in plane.

Plane is defined by point and direction in XY and Z axis. Intersection of circle (or straight line) and straight line in XY.

Parameters

[in]	point	point (XYZ) (defining origin of plane)
[in]	measPhi	measurement direction in (XY) plane
[out]	xyPos	position in plane along (XY) measurement direction (relative to point).
[out]	zPos	position in plane along Z direction (relative to point).
[out]	sArc	arc-length at intersection
[out]	phi	phi (flight direction) at intersection
[out]	lambda	lambda (flight direction) at intersection

Returns: success (intersection exists)

Definition at line 207 of file SimpleHelixTrackModel.cc.

References _dca, _dzds, _eps, _phi0, _rinv, _xref, _xRelCenter, _yref, _yRelCenter, _z0, and _zref.

Referenced by marlintpc::rb_Segment::match(), marlintpc::RowBasedPadPulseRoadSearchProcessor::processEvent(), and marlintpc::pb_Seed::roadSearch().

◆ getPosAtArcLength()

void marlintpc::simpleHelix::getPosAtArcLength	(	const double	sArc,
		double *	position
	)		const

Get position (on helix) at arc length.

Parameters

[in]	sArc	(2D) arc length
[out]	position	(XYZ) Position

Definition at line 179 of file SimpleHelixTrackModel.cc.

References _dca, _dzds, _eps, _phi0, _rinv, _xref, _xRelCenter, _yref, _yRelCenter, _z0, and _zref.

Referenced by marlintpc::StepWiseHelixGeneralBrokenLineInterfaceProcessor::processEvent().

◆ getStateAt()

void marlintpc::simpleHelix::getStateAt	(	const double	posX,
		const double	posY,
		const double	posZ,
		TMatrixDSym &	refCov,
		TVectorD &	newPar,
		TMatrixDSym &	newCov
	)

Get state (parameters, covariance matrix) at point.

Parameters

[in]	posX	point (X coordinate)
[in]	posY	point (Y coordinate)
[in]	posZ	point (Z coordinate)
[in]	refCov	covariance matrix at reference point
[out]	newPar	parameter vector at point
[out]	newCov	covariance matrix at point

Definition at line 444 of file SimpleHelixTrackModel.cc.

References _dca, _dzds, _eps, _phi0, _rinv, _xref, _yref, _z0, and _zref.

Referenced by marlintpc::rb_Segment::getLCIOStateAtRefPoint(), marlintpc::tp_PixelSegment::getLCIOStateAtRefPoint(), marlintpc::rb_Segment::match(), marlintpc::tp_PixelSegment::match(), and marlintpc::rb_Segment::rb_Segment().

◆ getZSDirection()

void marlintpc::simpleHelix::getZSDirection ( double * direction ) const

Get ZS direction (cosLambda, sinLambda).

Definition at line 167 of file SimpleHelixTrackModel.cc.

References _dzds.

◆ helixToLCIOJacobian()

TMatrixD marlintpc::simpleHelix::helixToLCIOJacobian ( ) const

Get transformation from helix to LCIO track parameters (at reference point)

(rinv, phi0, dca, dzds, z0) -> ( d0, phi0, Omega, z0, tanLambda)

d0 = -dca, phi0 = phi0, omega = -rinv, , z0 = z0, tan(lambda) = dzds

Returns: (5*5) transformation matrix

Definition at line 384 of file SimpleHelixTrackModel.cc.

Referenced by marlintpc::rb_Segment::getLCIOStateAtRefPoint(), and marlintpc::tp_PixelSegment::getLCIOStateAtRefPoint().

◆ moveTo()

void marlintpc::simpleHelix::moveTo	(	const double	newRefX,
		const double	newRefY,
		const double	newRefZ,
		double *	newPar
	)

Change reference point.

Parameters

[in]	newRefX	new reference point (X coordinate)
[in]	newRefY	new reference point (Y coordinate)
[in]	newRefZ	new reference point (Z coordinate)
[out]	newPar	new helix parameter array[5]

Definition at line 403 of file SimpleHelixTrackModel.cc.

References _dca, _dzds, _eps, _phi0, _rinv, _xref, _yref, _z0, and _zref.

◆ perigeeToILDJacobian()

TMatrixD marlintpc::simpleHelix::perigeeToILDJacobian ( ) const

Get transformation from perigee to L3/ILD track parameters (at reference point)

(kappa, theta, phi, epsilon, z_p) -> (omega, tan(lambda), phi, d0, z0)

omega = -kappa, lambda = pi/2 - theta, d0 = -epsilon, z0 = z_p

Returns: (5*5) transformation matrix

Definition at line 345 of file SimpleHelixTrackModel.cc.

References _dzds.

◆ perigeeToLCIOJacobian()

TMatrixD marlintpc::simpleHelix::perigeeToLCIOJacobian ( ) const

Get transformation from helix to LCIO track parameters (at reference point)

(kappa, theta, phi, epsilon, z_p) -> ( d0, phi0, Omega, z0, tanLambda)

d0 = -epsilon, phi0 = phi, omega = -kappa, , z0 = z_p, lambda = pi/2 - theta

Returns: (5*5) transformation matrix

Definition at line 364 of file SimpleHelixTrackModel.cc.

References _dzds.

Referenced by marlintpc::SimpleHelixGeneralBrokenLineInterfaceProcessor::processEvent(), and marlintpc::StepWiseHelixGeneralBrokenLineInterfaceProcessor::processEvent().

◆ simplifiedHelixJacobian()

TMatrixD marlintpc::simpleHelix::simplifiedHelixJacobian	(	const double	phi1,
		const double	ds
	)		const

Get simplified helix propagator (in constant solenoidal magnetic field)

Parabola with curvilinear track parameters (q/p,lambda,phi,x_t,y_t).

Parameters

[in]	phi1	azimutal direction at start point
[in]	ds	(3D) arc length to end point

Returns: (5*5) propagation matrix

Definition at line 277 of file SimpleHelixTrackModel.cc.

References _bzc, and _dzds.

Member Data Documentation

◆ _bzc

const double marlintpc::simpleHelix::_bzc

protected

Z component of magnetic field (*c)

Definition at line 48 of file SimpleHelixTrackModel.h.

Referenced by analyticalHelixJacobian(), curvilinearToPerigeeJacobian(), and simplifiedHelixJacobian().

◆ _dca

const double marlintpc::simpleHelix::_dca

protected

distance of closest approach in (XY)

Definition at line 54 of file SimpleHelixTrackModel.h.

Referenced by dump(), getExpectedPlanePos(), getPosAtArcLength(), getStateAt(), and moveTo().

◆ _dzds

const double marlintpc::simpleHelix::_dzds

protected

dZ/ds

Definition at line 56 of file SimpleHelixTrackModel.h.

Referenced by analyticalHelixJacobian(), curvilinearToPerigeeJacobian(), dump(), getExpectedPlanePos(), getPosAtArcLength(), getStateAt(), getZSDirection(), moveTo(), perigeeToILDJacobian(), perigeeToLCIOJacobian(), and simplifiedHelixJacobian().

◆ _eps

const double marlintpc::simpleHelix::_eps

protected

cut off for straight line approximation (|relevent scale / R| < _eps)

Definition at line 64 of file SimpleHelixTrackModel.h.

Referenced by getArcLengthXY(), getExpectedPlanePos(), getPosAtArcLength(), getStateAt(), and moveTo().

◆ _phi0

const double marlintpc::simpleHelix::_phi0

protected

flight direction at point of closest approach (in XY)

Definition at line 52 of file SimpleHelixTrackModel.h.

Referenced by curvilinearToPerigeeJacobian(), dump(), getArcLengthXY(), getExpectedPlanePos(), getPosAtArcLength(), getStateAt(), and moveTo().

◆ _rinv

const double marlintpc::simpleHelix::_rinv

protected

1/R

Definition at line 50 of file SimpleHelixTrackModel.h.

Referenced by analyticalHelixJacobian(), curvilinearToPerigeeJacobian(), dump(), getArcLengthXY(), getExpectedPlanePos(), getPosAtArcLength(), getStateAt(), and moveTo().

◆ _xref

const double marlintpc::simpleHelix::_xref

protected

X of reference point.

Definition at line 42 of file SimpleHelixTrackModel.h.

Referenced by dump(), getArcLengthXY(), getExpectedPlanePos(), getPosAtArcLength(), getStateAt(), and moveTo().

◆ _xRelCenter

const double marlintpc::simpleHelix::_xRelCenter

protected

XY circle parameter: X position of center / R.

Definition at line 60 of file SimpleHelixTrackModel.h.

Referenced by dump(), getArcLengthXY(), getExpectedPlanePos(), and getPosAtArcLength().

◆ _yref

const double marlintpc::simpleHelix::_yref

protected

Y of reference point.

Definition at line 44 of file SimpleHelixTrackModel.h.

Referenced by dump(), getArcLengthXY(), getExpectedPlanePos(), getPosAtArcLength(), getStateAt(), and moveTo().

◆ _yRelCenter

const double marlintpc::simpleHelix::_yRelCenter

protected

XY circle parameter: Y position of center / R.

Definition at line 62 of file SimpleHelixTrackModel.h.

Referenced by dump(), getArcLengthXY(), getExpectedPlanePos(), and getPosAtArcLength().

◆ _z0

const double marlintpc::simpleHelix::_z0

protected

Z position at distance of closest approach.

Definition at line 58 of file SimpleHelixTrackModel.h.

Referenced by dump(), getExpectedPlanePos(), getPosAtArcLength(), getStateAt(), and moveTo().

◆ _zref

const double marlintpc::simpleHelix::_zref

protected

Z of reference point.

Definition at line 46 of file SimpleHelixTrackModel.h.

Referenced by dump(), getExpectedPlanePos(), getPosAtArcLength(), getStateAt(), and moveTo().

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

Public Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ simpleHelix() [1/2]

◆ simpleHelix() [2/2]

Member Function Documentation

◆ analyticalHelixJacobian()

◆ curvilinearToPerigeeJacobian()

◆ dump()

◆ getArcLengthXY()

◆ getExpectedPlanePos()

◆ getPosAtArcLength()

◆ getStateAt()

◆ getZSDirection()

◆ helixToLCIOJacobian()

◆ moveTo()

◆ perigeeToILDJacobian()

◆ perigeeToLCIOJacobian()

◆ simplifiedHelixJacobian()

Member Data Documentation

◆ _bzc

◆ _dca

◆ _dzds

◆ _eps

◆ _phi0

◆ _rinv

◆ _xref

◆ _xRelCenter

◆ _yref

◆ _yRelCenter

◆ _z0

◆ _zref