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KalmanTrackToTrackCovCalculator< N > Class Template Reference

Calculates all the track-to-track covariance matrices using the Kalman filter algorithms after the vertex has been fit and the tracks refit. More...

#include <RecoVertex/KalmanVertexFit/interface/KalmanTrackToTrackCovCalculator.h>

Inheritance diagram for KalmanTrackToTrackCovCalculator< N >:

List of all members.

Public Types
typedef CachingVertex< N > ::RefCountedVertexTrack	RefCountedVertexTrack
Public Member Functions
KalmanTrackToTrackCovCalculator *	clone () const
	KalmanTrackToTrackCovCalculator ()
CachingVertex< N >::TrackToTrackMap	operator() (const CachingVertex< N > &vertex) const
	Calculates all the track-to-track covariance matrices.

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Detailed Description

template<unsigned int N>
class KalmanTrackToTrackCovCalculator< N >

Calculates all the track-to-track covariance matrices using the Kalman filter algorithms after the vertex has been fit and the tracks refit.

Definition at line 13 of file KalmanTrackToTrackCovCalculator.h.

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Member Typedef Documentation

template<unsigned int N>

typedef CachingVertex<N>::RefCountedVertexTrack KalmanTrackToTrackCovCalculator< N >::RefCountedVertexTrack

Definition at line 18 of file KalmanTrackToTrackCovCalculator.h.

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Constructor & Destructor Documentation

template<unsigned int N>

KalmanTrackToTrackCovCalculator< N >::KalmanTrackToTrackCovCalculator

(

)

[inline]

Definition at line 20 of file KalmanTrackToTrackCovCalculator.h.

Referenced by KalmanTrackToTrackCovCalculator< N >::clone().

{}

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Member Function Documentation

template<unsigned int N>

KalmanTrackToTrackCovCalculator* KalmanTrackToTrackCovCalculator< N >::clone

(

void

)

const [inline, virtual]

Implements TrackToTrackCovCalculator< N >.

Definition at line 31 of file KalmanTrackToTrackCovCalculator.h.

References KalmanTrackToTrackCovCalculator< N >::KalmanTrackToTrackCovCalculator().

 {
   return new KalmanTrackToTrackCovCalculator(* this);
 }

template<unsigned int N>

CachingVertex< N >::TrackToTrackMap KalmanTrackToTrackCovCalculator< N >::operator()

(

const CachingVertex< N > &

vertex

)

const [inline, virtual]

Calculates all the track-to-track covariance matrices.

Parameters:

vertex

The vertex whose track-to-track covariance matrices have to be calculated.

Returns:

The map containing the covariance matrices.

Implements TrackToTrackCovCalculator< N >.

Definition at line 7 of file KalmanTrackToTrackCovCalculator.cc.

References i, j, N, and tracks.

{
  typedef ROOT::Math::SMatrix<double,N,3,ROOT::Math::MatRepStd<double,N,3> > AlgebraicMatrixN3;
  typedef ROOT::Math::SMatrix<double,N,N-2,ROOT::Math::MatRepStd<double,N,N-2> > AlgebraicMatrixNM;
  typedef ROOT::Math::SMatrix<double,N-2,3,ROOT::Math::MatRepStd<double,N-2,3> > AlgebraicMatrixM3;
  typedef ROOT::Math::SMatrix<double,3,N-2,ROOT::Math::MatRepStd<double,3,N-2> > AlgebraicMatrix3M;
  typedef ROOT::Math::SMatrix<double,N,N,ROOT::Math::MatRepSym<double,N> > AlgebraicSymMatrixNN;
  typedef ROOT::Math::SMatrix<double,N-2,N-2,ROOT::Math::MatRepSym<double,N-2> > AlgebraicSymMatrixMM;
  typedef ROOT::Math::SMatrix<double,N-2,N-2,ROOT::Math::MatRepStd<double,N-2,N-2> > AlgebraicMatrixMM;

  typename CachingVertex<N>::TrackToTrackMap returnMap;
  int ifail = 0;
  vector<RefCountedVertexTrack> tracks = vertex.tracks();

//vertex initial data needed
  AlgebraicSymMatrix33 vertexC = vertex.error().matrix_new();

  for(typename vector<RefCountedVertexTrack>::iterator i = tracks.begin(); 
        i != tracks.end(); i++)
  {        
    const AlgebraicMatrixN3 & leftA = (*i)->linearizedTrack()->positionJacobian();
    const AlgebraicMatrixNM & leftB = (*i)->linearizedTrack()->momentumJacobian();
    AlgebraicSymMatrixNN leftG = (*i)->linearizedTrack()->predictedStateWeight();
    AlgebraicSymMatrixMM leftW = ROOT::Math::SimilarityT(leftB,leftG);

    ifail = ! leftW.Invert();
    if(ifail != 0) throw VertexException
        ("KalmanTrackToTrackCovarianceCalculator::leftW matrix inversion failed");
    AlgebraicMatrixM3 leftPart = leftW * (ROOT::Math::Transpose(leftB)) * leftG * leftA;
    typename CachingVertex<N>::TrackMap internalMap;
    for(typename vector<RefCountedVertexTrack>::iterator j = tracks.begin(); j != tracks.end(); j++)
    {

      if(*i < *j)
      {

        const AlgebraicMatrixN3 & rightA = (*j)->linearizedTrack()->positionJacobian();
        const AlgebraicMatrixNM & rightB = (*j)->linearizedTrack()->momentumJacobian();
        AlgebraicSymMatrixNN rightG = (*j)->linearizedTrack()->predictedStateWeight();
        AlgebraicSymMatrixMM rightW = ROOT::Math::SimilarityT(rightB,rightG);

        ifail = ! rightW.Invert();

        if(ifail != 0) throw VertexException
          ("KalmanTrackToTrackCovarianceCalculator::rightW matrix inversion failed");
        AlgebraicMatrix3M rightPart = (ROOT::Math::Transpose(rightA)) * rightG * rightB * rightW;
        AlgebraicMatrixMM covariance  = leftPart * vertexC * rightPart;
        internalMap[(*j)] = AlgebraicSymMatrixMM(covariance.LowerBlock());
      }       
    }        
    returnMap[*i] = internalMap;
  }
  return returnMap;
}

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

• RecoVertex/KalmanVertexFit/interface/KalmanTrackToTrackCovCalculator.h
• RecoVertex/KalmanVertexFit/src/KalmanTrackToTrackCovCalculator.cc

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