The class 'ThreeHitFilters' bundles filter methods using 3 hits which are stored in TVector3s. More...

#include <ThreeHitFilters.h>

Collaboration diagram for ThreeHitFilters:

Public Member Functions
	ThreeHitFilters ()
	Empty constructor. More...

	ThreeHitFilters (const TVector3 &outerHit, const TVector3 &centerHit, const TVector3 &innerHit, const double magneticFieldStrength=1.5)
	Constructor. More...

	~ThreeHitFilters ()
	Destructor.

void	resetValues (const TVector3 &outerHit, const TVector3 &centerHit, const TVector3 &innerHit)
	Overrides Constructor-Setup. More...

void	resetMagneticField (const double magneticFieldStrength=1.5)
	Overrides Constructor-Setup for magnetic field. More...

double	getMagneticField ()
	returns the set value of the magnetic field in Tesla

double	filterNan (double value)
	returns zero if value is nan or inf

double	calcAngle3D ()
	calculates the angle between the hits/vectors (3D), returning unit: none (calculation for degrees is incomplete, if you want readable numbers, use fullAngle3D instead)

double	fullAngle3D ()
	calculates the angle between the hits/vectors (3D), returning unit: angle in degrees

double	calcAngleXY ()
	calculates the angle between the hits/vectors (XY), returning unit: none (calculation for degrees is incomplete, if you want readable numbers, use fullAngleXY instead)

double	fullAngleXY ()
	calculates the angle between the hits/vectors (XY), returning unit: angle in degrees

double	calcAngleRZ ()
	calculates the angle between the hits/vectors (RZ), returning unit: none (calculation for degrees is incomplete, if you want readable numbers, use fullAngleRZ instead)

double	fullAngleRZ ()
	calculates the angle between the hits/vectors (RZ), returning unit: angle in degrees

double	calcCircleDist2IP ()
	calculates the distance of the point of closest approach of circle to the IP, returning unit: cm

double	calcPt ()
	calculates the estimation of the transverse momentum of the 3-hit-tracklet, returning unit: GeV/c

double	calcPt (double radius)
	calculates the estimation of the transverse momentum of given radius using defined strength of magnetic field, returning unit: GeV/c

double	calcDeltaSlopeRZ ()
	calculates deviations in the slope of the inner segment and the outer segment, returning unit: none

double	calcDeltaSOverZ ()
	calculates the helixparameter describing the deviation in arc length per unit in z. More...

double	calcDeltaSlopeZOverS ()
	compares the "slopes" z over arc length. More...

double	calcHelixParameterFit ()
	calculates the helixparameter describing the deviation in z per unit angle, returning unit: none

double	calcHelixFit ()
	reverse compatibility, calls calcHelixParameterFit

double	calcAngle2D (const TVector3 &vecA, const TVector3 &vecB)
	calculates the angle between the hits/vectors (2D), generalized, returning unit: none. More...

double	fullAngle2D (const TVector3 &vecA, const TVector3 &vecB)
	calculates the angle between the hits/vectors (2D), generalized, returning unit: angle in radians WARNING it is radians, which is incompatible to fullAngle3D (°))

double	calcRadius (const TVector3 &a, const TVector3 &b, const TVector3 &c, const TVector3 &circleCenter)
	calculates an estimation of the radius of given hits and existing estimation of circleCenter, returning unit: radius in [cm] (positive value)

void	calcCircleCenter (const TVector3 &a, const TVector3 &b, const TVector3 &c, TVector3 &circleCenter)
	calculates an estimation of circleCenter position, result is written into the 4th input-parameter

int	calcSign (const TVector3 &a, const TVector3 &b, const TVector3 &c)
	calculates calculates the sign of the curvature of given 3-hit-tracklet. More...

int	calcSign (const TVector3 &a, const TVector3 &b, const TVector3 &c, const TVector3 &sigma_a, const TVector3 &sigma_b, const TVector3 &sigma_c)
	calculates calculates the sign of the curvature of given 3-hit-tracklet. More...

Protected Member Functions
void	checkCalcCircleCenter ()
	checks whether the calcCircleCenter()-Member has been executed already and executes it if not

void	checkCalcRadius ()
	checks whether the calcRadius()-Member has been executed already and executes it if not

void	sanityCheckRadius (double radius)
	check Radius for bad values and throw exception if the value is bad

Protected Attributes
TwoHitFilters	m_twoHitFilter
	instance of TwoHitFilters-class used for some internal calculations

bool	m_circleCenterCalculated
	initially set to false, will be set true if calcCircleCenter() is used at least once

bool	m_radiusCalculated
	initially set to false, will be set true if calcInvCurvature() is used at least once

double	m_radius
	radius[cm] of a circle in r-phi-plane formed by the 3 hits

double	m_x2
	internal intermediate value storing x^2, no enduser-relevance

double	m_y2
	internal intermediate value storing y^2, no enduser-relevance

double	m_z2
	internal intermediate value storing z^2, no enduser-relevance

double	m_magneticFieldFactor
	is factor containing speed of light (c), the magnetic field (b) and the scaling factor s for conversion of meter in cm : cb/100 = cb*s

TVector3	m_centerABC
	center position of a circle in r-phi-plane formed by the 3 hits

TVector3	m_hitA
	outer hit (position relevant for useful filter calculation) used for the filter calculation

TVector3	m_hitB
	center hit (position relevant for useful filter calculation) used for the filter calculation

TVector3	m_hitC
	inner hit (position relevant for useful filter calculation) used for the filter calculation

TVector3	m_vecAB
	vector pointing from center hit to outer hit (outer segment)

TVector3	m_vecBC
	vector pointing from inner hit to center hit (inner segment)

Detailed Description

The class 'ThreeHitFilters' bundles filter methods using 3 hits which are stored in TVector3s.

Definition at line 23 of file ThreeHitFilters.h.

Constructor & Destructor Documentation

◆ ThreeHitFilters() [1/2]

ThreeHitFilters ( )

inline

Empty constructor.

For initialisation only, an object generated this way is useless unless resetValues(a, b) is called at least once

Definition at line 27 of file ThreeHitFilters.h.

                      :
       m_circleCenterCalculated(false),
       m_radiusCalculated(false),
       m_radius(0.),
       m_x2(0.),
       m_y2(0.),
       m_z2(0.)
     {
       m_hitA.SetXYZ(0., 0., 0.);
       m_hitB.SetXYZ(0., 0., 0.);
       m_hitC.SetXYZ(0., 0., 0.);
       m_vecAB.SetXYZ(0., 0., 0.);
       m_vecBC.SetXYZ(0., 0., 0.);
       resetMagneticField(1.5);
     }

◆ ThreeHitFilters() [2/2]

ThreeHitFilters	(	const TVector3 &	outerHit,
		const TVector3 &	centerHit,
		const TVector3 &	innerHit,
		const double	magneticFieldStrength = `1.5`
	)

inline

Constructor.

needs the first parameter is outer hit, second is center hit, third is inner hit. Parameters in TVector3-format, Optional parameter is the strength of the magnetic field in Tesla

x-part of m_vecAB.Dot(m_vecBC)

y-part of m_vecAB.Dot(m_vecBC)

z-part of m_vecAB.Dot(m_vecBC)

Definition at line 44 of file ThreeHitFilters.h.

Member Function Documentation

◆ calcAngle2D()

double calcAngle2D	(	const TVector3 &	vecA,
		const TVector3 &	vecB
	)

inline

calculates the angle between the hits/vectors (2D), generalized, returning unit: none.

used by calcAngleRZ and calcHelixFit (angleXY could use it too, but this one profits from other optimizations instead)

Definition at line 264 of file ThreeHitFilters.h.

◆ calcDeltaSlopeZOverS()

double calcDeltaSlopeZOverS ( )

inline

compares the "slopes" z over arc length.

calcDeltaSlopeZOverS is invariant under rotations in the r-z plane.

Definition at line 228 of file ThreeHitFilters.h.

◆ calcDeltaSOverZ()

double calcDeltaSOverZ ( )

inline

calculates the helixparameter describing the deviation in arc length per unit in z.

returning unit: radians*cm

Definition at line 211 of file ThreeHitFilters.h.

◆ calcSign() [1/2]

int calcSign	(	const TVector3 &	a,
		const TVector3 &	b,
		const TVector3 &	c
	)

calculates calculates the sign of the curvature of given 3-hit-tracklet.

a positive value represents a left-oriented curvature, a negative value means having a right-oriented curvature. first vector should be outer hit, second = center hit, third is inner hit

Definition at line 19 of file ThreeHitFilters.cc.

 {
   TVector3 ba = a - b; ba.SetZ(0.);
   TVector3 bc = b - c; bc.SetZ(0.);
   return sign(bc.Orthogonal() * ba); //normal vector of m_vecBC times segment of ba
 }

◆ calcSign() [2/2]

int calcSign	(	const TVector3 &	a,
		const TVector3 &	b,
		const TVector3 &	c,
		const TVector3 &	sigma_a,
		const TVector3 &	sigma_b,
		const TVector3 &	sigma_c
	)

inline

calculates calculates the sign of the curvature of given 3-hit-tracklet.

+1 represents a left-oriented curvature, -1 means having a right-oriented curvature. 0 means it is approximately straight. first vector should be outer hit, second = center hit, third is inner hit

Definition at line 323 of file ThreeHitFilters.h.

◆ resetMagneticField()

void resetMagneticField ( const double magneticFieldStrength = 1.5 )

inline

Overrides Constructor-Setup for magnetic field.

If no value is given, magnetic field is assumed to be Belle2-Detector standard of 1.5T. pT[GeV/c] = 0.299710*B[T]*r[m] = 0.299710*B[T]*r[cm]/100 = 0.00299710B[T]*r[cm]

Definition at line 89 of file ThreeHitFilters.h.

◆ resetValues()

void resetValues	(	const TVector3 &	outerHit,
		const TVector3 &	centerHit,
		const TVector3 &	innerHit
	)

inline

Overrides Constructor-Setup.

Needed if you want to reuse the instance instead of recreating one

x-part of m_vecAB.Dot(m_vecBC)

y-part of m_vecAB.Dot(m_vecBC)

z-part of m_vecAB.Dot(m_vecBC)

Definition at line 66 of file ThreeHitFilters.h.

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

tracking/vxdCaTracking/include/ThreeHitFilters.h
tracking/vxdCaTracking/src/ThreeHitFilters.cc

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ ThreeHitFilters() [1/2]

◆ ThreeHitFilters() [2/2]

Member Function Documentation

◆ calcAngle2D()

◆ calcDeltaSlopeZOverS()

◆ calcDeltaSOverZ()

◆ calcSign() [1/2]

◆ calcSign() [2/2]

◆ resetMagneticField()

◆ resetValues()