#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	dR12
double	dS12
double	dZ12
double	sqr_errorXY12
double	sqr_errorXY2
double	theCurvature
double	theErrorZ1
double	theErrorZ2
double	theNSigma
GlobalPoint	thePoint2

Detailed Description

Definition at line 9 of file ThirdHitZPrediction.h.

Member Typedef Documentation

typedef PixelRecoRange<float> ThirdHitZPrediction::Range

Definition at line 11 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.`
	)		`[inline]`

Definition at line 12 of file ThirdHitZPrediction.h.

References abs, dR12, dS12, dZ12, alignCSCRings::e, p1, and theCurvature.

                                                             : 
    thePoint2(p2),
    sqr_errorXY12(erroRPhi1*erroRPhi1+erroRPhi2*erroRPhi2),
    sqr_errorXY2(erroRPhi2*erroRPhi2),
    theErrorZ1(errorZ1),
    theErrorZ2(errorZ2),
    theCurvature(curvature), theNSigma(nSigma){
    auto d = p2-p1;
    dR12 = d.perp();   if (dR12 < 1.e-5) dR12 = 1.e-5;
    dS12 = std::abs(0.5*dR12*theCurvature) <1 ? std::asin(0.5*dR12*theCurvature) : 1.;
    dZ12 = d.z();
  }

Member Function Documentation

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

Definition at line 8 of file ThirdHitZPrediction.cc.

References abs, dR12, dS12, dZ12, alignCSCRings::e, error, perp(), slope, funct::sqr(), sqr_errorXY12, sqr_errorXY2, mathSSE::sqrt(), theCurvature, theErrorZ1, theErrorZ2, theNSigma, thePoint2, and PV3DBase< T, PVType, FrameType >::z().

{
  double dR23 = (thePoint3-thePoint2).perp();

  double slope = dR23/dR12;
  if (    (theCurvature > 1.e-4) 
          && (std::abs(0.5*dR23*theCurvature) < 1.) 
          ) slope = std::asin(0.5*dR23*theCurvature)/dS12;

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

  double sqr_errorXY23 = sqr_errorXY2+sqr(erroRPhi3);
  double error = sqrt( sqr( (1+dR23/dR12)*theErrorZ2 )
                       + sqr( dR23/dR12 * theErrorZ1 )
                       + sqr(dZ12/dR12 )*sqr_errorXY23 
                       + sqr((dZ12/dR12)*(dR23/dR12))*sqr_errorXY12
                       );
  error *= theNSigma;
  return Range(z3-error,z3+error);
}