CMSSW Reference Manual

00001 #include "RecoVertex/KalmanVertexFit/interface/KalmanVertexTrackUpdator.h"
00002 #include "TrackingTools/TrajectoryState/interface/FreeTrajectoryState.h"
00003 //#include "Utilities/GenUtil/interface/ReferenceCountingPointer.h"
00004 #include "RecoVertex/VertexPrimitives/interface/VertexTrack.h"
00005 #include "RecoVertex/VertexPrimitives/interface/CachingVertex.h"
00006 #include "RecoVertex/VertexPrimitives/interface/VertexException.h"
00007 
00008 
00009 template <unsigned int N>
00010 typename CachingVertex<N>::RefCountedVertexTrack
00011 KalmanVertexTrackUpdator<N>::update
00012         (const CachingVertex<N> & vertex , RefCountedVertexTrack track) const
00013 
00014 {
00015   trackMatrixPair thePair = 
00016         trackRefit(vertex.vertexState(), track->linearizedTrack(), track->weight() );
00017 
00018   VertexState rVert = updator.positionUpdate (vertex.vertexState(), track->linearizedTrack(),
00019                         track->weight(), -1);
00020 
00021   float smoothedChi2 = helper.vertexChi2(rVert, vertex.vertexState()) +
00022         helper.trackParameterChi2(track->linearizedTrack(), thePair.first);
00023 
00024   return theVTFactory.vertexTrack(track->linearizedTrack(),
00025         vertex.vertexState(), thePair.first, smoothedChi2, thePair.second,
00026         track->weight());
00027 }
00028 
00029 template <unsigned int N>
00030 typename KalmanVertexTrackUpdator<N>::trackMatrixPair
00031 KalmanVertexTrackUpdator<N>::trackRefit(const VertexState & vertex,
00032          KalmanVertexTrackUpdator<N>::RefCountedLinearizedTrackState linTrackState,
00033          float weight) const
00034 
00035 {
00036   typedef ROOT::Math::SVector<double,N> AlgebraicVectorN;
00037   typedef ROOT::Math::SVector<double,N-2> AlgebraicVectorM;
00038   typedef ROOT::Math::SMatrix<double,N,3,ROOT::Math::MatRepStd<double,N,3> > AlgebraicMatrixN3;
00039   typedef ROOT::Math::SMatrix<double,N,N-2,ROOT::Math::MatRepStd<double,N,N-2> > AlgebraicMatrixNM;
00040   typedef ROOT::Math::SMatrix<double,N-2,3,ROOT::Math::MatRepStd<double,N-2,3> > AlgebraicMatrixM3;
00041   typedef ROOT::Math::SMatrix<double,N,N,ROOT::Math::MatRepSym<double,N> > AlgebraicSymMatrixNN;
00042   typedef ROOT::Math::SMatrix<double,N+1,N+1,ROOT::Math::MatRepSym<double,N+1> > AlgebraicSymMatrixOO;
00043   typedef ROOT::Math::SMatrix<double,N+1,N+1,ROOT::Math::MatRepStd<double,N+1,N+1> > AlgebraicMatrixOO;
00044   typedef ROOT::Math::SMatrix<double,N-2,N-2,ROOT::Math::MatRepSym<double,N-2> > AlgebraicSymMatrixMM;
00045 
00046   //Vertex position 
00047   GlobalPoint vertexPosition = vertex.position();
00048 
00049   AlgebraicVector3 vertexCoord;
00050   vertexCoord(0) = vertexPosition.x();
00051   vertexCoord(1) = vertexPosition.y();
00052   vertexCoord(2) = vertexPosition.z();
00053   AlgebraicSymMatrix33 vertexErrorMatrix = vertex.error().matrix_new();
00054 
00055 //track information
00056   const AlgebraicMatrixN3 & a = linTrackState->positionJacobian();
00057   const AlgebraicMatrixNM & b = linTrackState->momentumJacobian();
00058 
00059 //   AlgebraicVectorN trackParameters = 
00060 //      linTrackState->predictedStateParameters();
00061 
00062   AlgebraicSymMatrixNN trackParametersWeight = 
00063         linTrackState->predictedStateWeight();
00064 
00065   AlgebraicSymMatrixMM s = ROOT::Math::SimilarityT(b,trackParametersWeight);
00066   
00067   int ifail = ! s.Invert();
00068   if(ifail !=0) throw VertexException
00069         ("KalmanVertexTrackUpdator::S matrix inversion failed");
00070    
00071   AlgebraicVectorM newTrackMomentumP =  s * (ROOT::Math::Transpose(b)) * trackParametersWeight * 
00072     (linTrackState->predictedStateParameters() - linTrackState->constantTerm() - a*vertexCoord);
00073 
00074   AlgebraicMatrix3M refittedPositionMomentumConvariance = 
00075     -vertexErrorMatrix * (ROOT::Math::Transpose(a)) * trackParametersWeight * b * s;
00076 
00077   AlgebraicSymMatrixMM refittedMomentumConvariance = s/weight +  
00078      ROOT::Math::SimilarityT(refittedPositionMomentumConvariance, vertex.weight().matrix_new());
00079 
00080   
00081  // int matrixSize = 3+3; //refittedMomentumConvariance.num_col();
00082   AlgebraicMatrixOO  covMatrix; //(matrixSize, matrixSize);
00083   covMatrix.Place_at(refittedPositionMomentumConvariance, 0, 3);
00084   covMatrix.Place_at(ROOT::Math::Transpose(refittedPositionMomentumConvariance), 3, 0);
00085   covMatrix.Place_at(vertexErrorMatrix, 0, 0);
00086   covMatrix.Place_at(refittedMomentumConvariance, 3 ,3);
00087 
00088   AlgebraicSymMatrixOO covSymMatrix(covMatrix.LowerBlock());
00089 
00090   RefCountedRefittedTrackState refittedTrackState = linTrackState->
00091         createRefittedTrackState(vertexPosition, newTrackMomentumP, covSymMatrix);
00092 
00093   return pair<RefCountedRefittedTrackState, AlgebraicMatrix3M>
00094                 (refittedTrackState, refittedPositionMomentumConvariance);
00095 } 
00096 
00097 template class KalmanVertexTrackUpdator<5>;
00098 template class KalmanVertexTrackUpdator<6>;
KalmanVertexTrackUpdator.cc
