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TrajectoryStateAccessor Class Reference

Helper class to obtain the uncertainty on specific trajectory parameters. More...

#include <TrackingTools/TrajectoryState/interface/TrajectoryStateAccessor.h>

List of all members.

Public Member Functions
double	inversePtError () const
	TrajectoryStateAccessor (const FreeTrajectoryState &fts)
Private Attributes
const FreeTrajectoryState &	theFts

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Detailed Description

Helper class to obtain the uncertainty on specific trajectory parameters.

Definition at line 10 of file TrajectoryStateAccessor.h.

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Constructor & Destructor Documentation

TrajectoryStateAccessor::TrajectoryStateAccessor

(

const FreeTrajectoryState &

fts

)

[inline]

Definition at line 13 of file TrajectoryStateAccessor.h.

                                                           :
    theFts(fts) {}

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Member Function Documentation

double TrajectoryStateAccessor::inversePtError

(

)

const

Definition at line 5 of file TrajectoryStateAccessor.cc.

References funct::cos(), FreeTrajectoryState::curvilinearError(), CurvilinearTrajectoryError::matrix(), FreeTrajectoryState::momentum(), PV3DBase< T, PVType, FrameType >::perp(), funct::sin(), funct::sqrt(), theFts, and PV3DBase< T, PVType, FrameType >::theta().

{
  GlobalVector momentum = theFts.momentum();
  AlgebraicSymMatrix55 errMatrix = theFts.curvilinearError().matrix();
  
  float SinTheta=sin(momentum.theta());
  float CosTheta=cos(momentum.theta());
  float ptRec=momentum.perp();
  float InvpErr=errMatrix(0,0);
  float thetaErr=errMatrix(1,1);
  float corr=errMatrix(0,1);
  float invPtErr2 = 1/(SinTheta*SinTheta)*
    (InvpErr + 
     ((CosTheta*CosTheta)/(ptRec*ptRec))*thetaErr - 
     2*(CosTheta/ptRec)*corr);
  return sqrt(invPtErr2);
}

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Member Data Documentation

const FreeTrajectoryState& TrajectoryStateAccessor::theFts [private]

Definition at line 20 of file TrajectoryStateAccessor.h.

Referenced by inversePtError().

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

• TrackingTools/TrajectoryState/interface/TrajectoryStateAccessor.h
• TrackingTools/TrajectoryState/src/TrajectoryStateAccessor.cc

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