SIGNCURVATUREXYERROR_NAME< PointType > Class Template Reference

calculates the sign of the curvature for three hits More...

#include <SignCurvatureXYError.h>

Inheritance diagram for SIGNCURVATUREXYERROR_NAME< PointType >:

Collaboration diagram for SIGNCURVATUREXYERROR_NAME< PointType >:

Public Types
typedef int	variableType
	Type of the returned object. More...
typedef PointType	argumentType
	Type of the argument object. More...
typedef FunctionOf< Nargs, variableType, const argumentType & >::functionType	functionType
	Type of the function returning the value. More...

Public Member Functions
	PUT_NAME_FUNCTION (SIGNCURVATUREXYERROR_NAME)
	is replaced by "static const std:string name(void)" frunction which returns name of the Class

Static Public Member Functions
static int	value (const PointType &a, const PointType &b, const PointType &c)
	calculates calculates the sign of the curvature of given 3-hit-tracklet. More...
static variableType	value (const PointType &arg1, const PointType &arg2)
	Static method that return the variable associated to: More...

Static Public Attributes
static const size_t	c_Nargs
	Number of arguments.

Detailed Description

template<typename PointType>
class Belle2::SIGNCURVATUREXYERROR_NAME< PointType >

calculates the sign of the curvature for three hits

Definition at line 28 of file SignCurvatureXYError.h.

Member Typedef Documentation

argumentType

typedef PointType argumentType

inherited

Type of the argument object.

Needed for SFINAE in Filter.hh

Definition at line 84 of file SelectionVariable.h.

functionType

typedef FunctionOf<Nargs, variableType, const argumentType&>::functionType functionType

inherited

Type of the function returning the value.

Needed for the automated training

Definition at line 88 of file SelectionVariable.h.

variableType

typedef int variableType

inherited

Type of the returned object.

Needed for SFINAE in Filter.hh

Definition at line 81 of file SelectionVariable.h.

Member Function Documentation

value() [1/2]

static int value ( const PointType &  a, const PointType &  b, const PointType &  c  )

inlinestatic

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 38 of file SignCurvatureXYError.h.

    {
      B2Vector3<double> sigma_a = a.getPositionError();
      B2Vector3<double> sigma_b = b.getPositionError();
      B2Vector3<double> sigma_c = c.getPositionError();
 
      B2Vector3<double> c2b(b.X() - c.X(), b.Y() - c.Y(), 0.0);
      B2Vector3<double> b2a(a.X() - b.X(), a.Y() - b.Y(), 0.0);
      //TODO: check if acos of the dot product is better (faster)
      double angle = atan2(b2a[0], b2a[1]) - atan2(c2b[0], c2b[1]);
      //TODO 1/3...mean of the sigmas. Possible improvement: Use a parameter instead, and determine with simulated events.
      double sigmaan = (sigma_a.Mag() + sigma_b.Mag() + sigma_c.Mag()) / (3.*(c2b.Mag() + b2a.Mag()));
      if (angle < (-sigmaan)) { return -1; }
      else if (angle > sigmaan)  {return 1; }
      else  { return 0; }
    }

value() [2/2]

static variableType value ( const templateArgumentType &  arg1, const templateArgumentType &  arg2  )

inlinestaticinherited

Static method that return the variable associated to:

Parameters

arg1	first object of the pair
arg2	second object of the pair

N.B. this method must be static.

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

• tracking/trackFindingVXD/filterMap/threeHitVariables/include/SignCurvatureXYError.h