#include <ThirdHitZPrediction.h>

Public Types
typedef PixelRecoRange< float >	Range
Public Member Functions
Range	operator() (const GlobalPoint &p3, float erroRPhi3) const
	ThirdHitZPrediction (const GlobalPoint &p1, float erroRPhi1, float errorZ1, const GlobalPoint &p2, float erroRPhi2, float errorZ2, double curvature, double nSigma=3.)
Private Attributes
double	theCurvature
double	theErrorXY1
double	theErrorXY2
double	theErrorZ1
double	theErrorZ2
double	theNSigma
GlobalPoint	thePoint1
GlobalPoint	thePoint2

Detailed Description

Definition at line 8 of file ThirdHitZPrediction.h.

Member Typedef Documentation

typedef PixelRecoRange<float> ThirdHitZPrediction::Range

Definition at line 10 of file ThirdHitZPrediction.h.

Constructor & Destructor Documentation

ThirdHitZPrediction::ThirdHitZPrediction	(	const GlobalPoint &	p1,
		float	erroRPhi1,
		float	errorZ1,
		const GlobalPoint &	p2,
		float	erroRPhi2,
		float	errorZ2,
		double	curvature,
		double	nSigma = `3.`
	)

Definition at line 4 of file ThirdHitZPrediction.cc.

  :
    thePoint1(p1), thePoint2(p2),
    theErrorXY1(erroRPhi1), theErrorZ1(errorZ1),
    theErrorXY2(erroRPhi2), theErrorZ2(errorZ2),
    theCurvature(curvature), theNSigma(nSigma)
{}

Member Function Documentation

ThirdHitZPrediction::Range ThirdHitZPrediction::operator()	(	const GlobalPoint &	p3,
		float	erroRPhi3
	)		const

Definition at line 15 of file ThirdHitZPrediction.cc.

References alignCSCRings::e, error, perp(), slope, funct::sqr(), mathSSE::sqrt(), theCurvature, theErrorXY1, theErrorXY2, theErrorZ1, theErrorZ2, theNSigma, thePoint1, thePoint2, and PV3DBase< T, PVType, FrameType >::z().

{
  double dR12 = (thePoint2-thePoint1).perp();
  if (dR12 < 1.e-5) dR12 = 1.e-5;
  double dR23 = (thePoint3-thePoint2).perp();
  double dZ12 = thePoint2.z()-thePoint1.z();

  double slope = dR23/dR12;
  if (    (theCurvature > 1.e-4) 
       && (fabs(dR23/2.*theCurvature) < 1.) 
       && (fabs(dR12/2.*theCurvature) <1.) 
         ) slope = asin(dR23/2.*theCurvature)/asin(dR12/2.*theCurvature);

  double z3 = thePoint2.z() + dZ12*slope;

  double sqr_errorXY12 = sqr(theErrorXY1)+sqr(theErrorXY2);
  double sqr_errorXY23 = sqr(theErrorXY2)+sqr(erroRPhi3);
  double error = sqrt( sqr( (1+dR23/dR12)*theErrorZ2 )
                     + sqr( dR23/dR12 * theErrorZ1 )
                     + sqr(dZ12/dR12 )*sqr_errorXY23 
                     + sqr(dZ12*dR23/dR12/dR12)*sqr_errorXY12
                     );
  error *= theNSigma;
  return Range(z3-error,z3+error);
}