CIRCLECENTERXY_NAME< PointType > Class Template Reference

calculates the center of the circle for 3 hits in the XY plane and returns a B2Vector3 with the result (z=0). More...

#include <CircleCenterXY.h>

Inheritance diagram for CIRCLECENTERXY_NAME< PointType >:

Public Types
typedef B2Vector3D	variableType
	Type of the returned object.
typedef PointType	argumentType
	Type of the argument object.
typedef FunctionOf< Nargs, variableType, constargumentType & >::functionType	functionType
	Type of the function returning the value.

Public Member Functions
	BELLE2_DEFINE_EXCEPTION (Straight_Line, "The hits are on a straight Line (or indistinguishably near to being on it).")
	this exception is thrown by the CircleFit and occurs when the track is too straight.
	PUT_NAME_FUNCTION (CIRCLECENTERXY_NAME)
	is replaced by "static const std:string name(void)" frunction which returns name of the Class

Static Public Member Functions
static B2Vector3D	value (const PointType &a, const PointType &b, const PointType &c)
	calculates an estimation of circleCenter position, result is returned as the x and y value of the B2Vector3.
static variableType	value (const PointType &arg1, const PointType &arg2)
	Static method that return the variable associated to:

Static Public Attributes
static const size_t	c_Nargs
	Number of arguments.

Detailed Description

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

calculates the center of the circle for 3 hits in the XY plane and returns a B2Vector3 with the result (z=0).

WARNING this method throws an exception!

Definition at line 27 of file CircleCenterXY.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,constargumentType&>::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 B2Vector3D 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 B2Vector3D value ( const PointType &  a, const PointType &  b, const PointType &  c  )

inlinestatic

calculates an estimation of circleCenter position, result is returned as the x and y value of the B2Vector3.

Definition at line 36 of file CircleCenterXY.h.

    {
      // calculates the intersection point using Cramer's rule.
      // x_1+s*n_1==x_2+t*n_2 --> n_1 *s - n_2 *t == x_2 - x_1 --> http://en.wikipedia.org/wiki/Cramer%27s_rule
      double inX = b.X() - c.X(); // x value of the normal vector of the inner segment (b-c)
      double inY = b.Y() - c.Y(); // y value of the normal vector of the inner segment (b-c)
      double outX = a.X() - b.X(); // x value of the normal vector of the outer segment (a-b)
      double outY = a.Y() - b.Y(); // y value of the normal vector of the outer segment (a-b)
 
      //searching solution for Ax = b, aij are the matrix elements of A, bi are elements of b
      double a11 = inY;
      double a12 = -inX;
      double a21 = -outY;
      double a22 = outX;
      double b1 = b.X() + outX * 0.5 - (c.X() + inX * 0.5);
      double b2 = b.Y() + outY * 0.5 - (c.Y() + inY * 0.5);
 
      if (a11 * a22 == a12 * a21) { throw Straight_Line(); }
 
      double s = (b1 * a22 - b2 * a21) / (a11 * a22 - a12 * a21); //the determinant is zero if the three hits are on a line in (x,y).
 
      return B2Vector3D(c.X() + inX * 0.5 + s * inY, c.Y() + inY * 0.5 - s * inX, 0.);
    }

value() [2/2]

static variableType value ( const PointType &  arg1, const PointType &  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.

Member Data Documentation

c_Nargs

const size_t c_Nargs

staticinherited

Number of arguments.

Definition at line 91 of file SelectionVariable.h.

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

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