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KalmanChiSquare Class Reference

#include <RecoVertex/AdaptiveVertexFit/interface/KalmanChiSquare.h>

List of all members.

Public Types
typedef ReferenceCountingPointer < LinearizedTrackState< 5 > >	RefCountedLinearizedTrackState
typedef ReferenceCountingPointer < VertexTrack< 5 > >	RefCountedVertexTrack
	A chi-2 criterion that relies on the Kalman formalism, exploiting data stored in LinearizedTrackState.
Public Member Functions
float	estimate (const GlobalPoint &, RefCountedLinearizedTrackState) const

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Detailed Description

Definition at line 9 of file KalmanChiSquare.h.

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Member Typedef Documentation

typedef ReferenceCountingPointer<LinearizedTrackState<5> > KalmanChiSquare::RefCountedLinearizedTrackState

Definition at line 18 of file KalmanChiSquare.h.

typedef ReferenceCountingPointer<VertexTrack<5> > KalmanChiSquare::RefCountedVertexTrack

A chi-2 criterion that relies on the Kalman formalism, exploiting data stored in LinearizedTrackState.

It needs only a VertexState, not a full

Definition at line 17 of file KalmanChiSquare.h.

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Member Function Documentation

float KalmanChiSquare::estimate	(	const GlobalPoint &	vertex,
		RefCountedLinearizedTrackState	lt
	)			const

Definition at line 6 of file KalmanChiSquare.cc.

References a, b, s, PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().

Referenced by AdaptiveVertexFitter::weightTracks().

{
  AlgebraicVector3 vtxposV;
  vtxposV[0] = vertex.x();
  vtxposV[1] = vertex.y();
  vtxposV[2] = vertex.z();

  AlgebraicMatrix53 a = lt->positionJacobian();
  AlgebraicMatrix53 b = lt->momentumJacobian();

  // track information
  AlgebraicVector5 trackParameters =
      lt->predictedStateParameters();

  AlgebraicSymMatrix55 trackParametersWeight =
      lt->predictedStateWeight();

  AlgebraicSymMatrix33 s = ROOT::Math::SimilarityT(b,trackParametersWeight);
  bool ret = s.Invert(); 
  if(!ret) throw VertexException
                       ("[KalmanChiSquare] S matrix inversion failed");

  AlgebraicVector5 residual = lt->constantTerm();
  AlgebraicVector3 newTrackMomentumP =  s * ROOT::Math::Transpose(b) * trackParametersWeight *
     (trackParameters - residual - a*vtxposV);

  AlgebraicVector5 rtp = ( residual +  a * vtxposV + b * newTrackMomentumP);

  AlgebraicVector5 parameterResiduals = trackParameters - rtp;
  lt->checkParameters(parameterResiduals);

  return ROOT::Math::Similarity(parameterResiduals, trackParametersWeight);
}

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

• RecoVertex/AdaptiveVertexFit/interface/KalmanChiSquare.h
• RecoVertex/AdaptiveVertexFit/src/KalmanChiSquare.cc

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