Trk::SequentialVertexFitter Class Reference

An iterative vertex fitter, updating the vertex estimate with a single at the time. More...

#include <SequentialVertexFitter.h>

Inheritance diagram for Trk::SequentialVertexFitter:

Collaboration diagram for Trk::SequentialVertexFitter:

Public Member Functions
virtual StatusCode	initialize () override
virtual StatusCode	finalize () override
	SequentialVertexFitter (const std::string &t, const std::string &n, const IInterface *p)
	constructor
virtual	~SequentialVertexFitter ()
	destructor
virtual std::unique_ptr< xAOD::Vertex >	fit (const EventContext &ctx, const std::vector< const xAOD::TrackParticle * > &vectorTrk, const std::vector< const xAOD::NeutralParticle * > &vectorNeut, const Amg::Vector3D &startingPoint) const override
	Interface for xAOD::TrackParticle and xAOD::NeutralParticle with starting point.
virtual std::unique_ptr< xAOD::Vertex >	fit (const EventContext &ctx, const std::vector< const xAOD::TrackParticle * > &vectorTrk, const Amg::Vector3D &startingPoint) const override
	Interface for xAOD::TrackParticle with starting point.
virtual std::unique_ptr< xAOD::Vertex >	fit (const EventContext &ctx, const std::vector< const xAOD::TrackParticle * > &vectorTrk, const std::vector< const xAOD::NeutralParticle * > &vectorNeut, const xAOD::Vertex &constraint) const override
	Interface for xAOD::TrackParticle and xAOD::NeutralParticle with vertex constraint the position of the constraint is ALWAYS the starting point.
virtual std::unique_ptr< xAOD::Vertex >	fit (const EventContext &ctx, const std::vector< const xAOD::TrackParticle * > &vectorTrk, const xAOD::Vertex &constraint) const override
	Interface for xAOD::TrackParticle with vertex constraint the position of the constraint is ALWAYS the starting point.
virtual std::unique_ptr< xAOD::Vertex >	fit (const EventContext &ctx, const std::vector< const Trk::TrackParameters * > &perigeeList, const std::vector< const Trk::NeutralParameters * > &neutralPerigeeList, const Amg::Vector3D &startingPoint) const override
	Vertex fit from list of track and neutral parameters and a starting point.
virtual std::unique_ptr< xAOD::Vertex >	fit (const EventContext &ctx, const std::vector< const Trk::TrackParameters * > &paramList, const Amg::Vector3D &startingPoint) const override
	Vertex fit from list of track and parameters and a starting point.
virtual std::unique_ptr< xAOD::Vertex >	fit (const EventContext &ctx, const std::vector< const Trk::TrackParameters * > &perigeeList, const std::vector< const Trk::NeutralParameters * > &neutralPerigeeList, const xAOD::Vertex &constraint) const override
	Vertex fit from the vector of track and neutral parameters with a preliminary knowledge (vertex constraint).
virtual std::unique_ptr< xAOD::Vertex >	fit (const EventContext &ctx, const std::vector< const Trk::TrackParameters * > &perigeeList, const xAOD::Vertex &constraint) const override
virtual std::unique_ptr< xAOD::Vertex >	fit (const EventContext &ctx, const std::vector< const Trk::TrackParameters * > &perigeeList, const std::vector< const Trk::NeutralParameters * > &neutralPerigeeList) const override
	Additional fit methods.
virtual std::unique_ptr< xAOD::Vertex >	fit (const EventContext &ctx, const std::vector< const Trk::TrackParameters * > &perigeeList) const override

Private Member Functions
std::vector< Trk::VxTrackAtVertex >	linearizeTracks (const std::vector< const Trk::TrackParameters * > &perigeeList, const std::vector< const Trk::NeutralParameters * > &neutralPerigeeList, const xAOD::Vertex &vrt) const
	Internal method related to the linearization of tracks (initial linearization).
void	reLinearizeTracks (std::vector< Trk::VxTrackAtVertex > &tracks, const Amg::Vector3D &vrt) const
	Relinearization on iterations.

Private Attributes
ToolHandle< IVertexUpdator >	m_Updator
ToolHandle< IVertexSmoother >	m_Smoother
ToolHandle< Trk::IVertexLinearizedTrackFactory >	m_LinTrkFactory
bool	m_doSmoothing
	Flag controlling optional smoothing.
unsigned int	m_maxStep
	Max number of iterations to perform (in case of no convergence).
float	m_maxShift
	Max shift (represents the convergence criterion).
bool	m_useLooseConvergence
	Use loose convergence criterium (maxShift) or hard (+maxDeltaChi2).
float	m_maxDeltaChi2
	Max DeltaChi2 allowed in hard convergence criterium.
double	m_maxR
double	m_maxZ

Detailed Description

An iterative vertex fitter, updating the vertex estimate with a single at the time.

The measurement equation is relinearized with the position of the resulting estimate and the vertex is refit The iterations are performed until the vertex position improves or the maximal niumber of iterations is reached. Smoothing (refit of tracks with the knowledge of the vertex position) is then performed on request.

The fitter can be used with arbitrary VertexUpdator, VertexSmoother and LinearizedTrackFactory

Author

Kirill Prokofiev, November 2005

---

Changes:

David Shope david.nosp@m..ric.nosp@m.hard..nosp@m.shop.nosp@m.e@cer.nosp@m.n.ch (2016-04-19) EDM Migration to xAOD - from Trk::VxCandidate to xAOD::Vertex, from Trk::RecVertex to xAOD::Vertex, from Trk::Vertex to Amg::Vector3D

Definition at line 55 of file SequentialVertexFitter.h.

Constructor & Destructor Documentation

SequentialVertexFitter()

Trk::SequentialVertexFitter::SequentialVertexFitter	(	const std::string &	t,
		const std::string &	n,
		const IInterface *	p )

constructor

Definition at line 58 of file SequentialVertexFitter.cxx.

                                                                                                           :
    base_class(t,n,p),
    m_Updator("Trk::KalmanVertexUpdator", this),
    
//    m_Smoother("Trk::KalmanVertexSmoother"),
    m_Smoother("Trk::DummyVertexSmoother",this),
    m_LinTrkFactory("Trk::FullPerigeeLinearizedTrackFactory",this),
    m_doSmoothing(true),
    m_maxStep(20),
    m_maxShift(0.0001),
    m_useLooseConvergence(false),
    m_maxDeltaChi2(1e-3),
    m_maxR(1150.),//max R of ID
    m_maxZ(2727.)
{
//convergence stuff 
  declareProperty("MaxIterations",m_maxStep);
  declareProperty("MaxShift",m_maxShift);
  declareProperty("useLooseConvergence",m_useLooseConvergence);
  declareProperty("maxDeltaChi2",m_maxDeltaChi2);
 
//updator-related stuff  
  declareProperty("VertexUpdator",m_Updator);
  
//smoother-related stuff 
  declareProperty("DoSmoothing",m_doSmoothing);
  declareProperty("VertexSmoother",m_Smoother);
  
  declareProperty("ID_maxR",m_maxR);
  declareProperty("ID_maxZ",m_maxZ);
 
//linearizedTrackFactory-related stuff  
  declareProperty("LinearizedTrackFactory", m_LinTrkFactory);
 }

~SequentialVertexFitter()

Trk::SequentialVertexFitter::~SequentialVertexFitter ( )

virtualdefault

destructor

Member Function Documentation

finalize()

StatusCode Trk::SequentialVertexFitter::finalize ( )

overridevirtual

Definition at line 52 of file SequentialVertexFitter.cxx.

 {
  return StatusCode::SUCCESS;
 }

fit() [1/10]

virtual std::unique_ptr< xAOD::Vertex > Trk::SequentialVertexFitter::fit ( const EventContext & ctx, const std::vector< const Trk::TrackParameters * > & paramList, const Amg::Vector3D & startingPoint ) const

inlineoverridevirtual

Vertex fit from list of track and parameters and a starting point.

Definition at line 122 of file SequentialVertexFitter.h.

       {return fit(ctx, paramList, std::vector<const Trk::NeutralParameters*>(), startingPoint);};

fit() [2/10]

virtual std::unique_ptr< xAOD::Vertex > Trk::SequentialVertexFitter::fit ( const EventContext & ctx, const std::vector< const Trk::TrackParameters * > & perigeeList ) const

inlineoverridevirtual

Definition at line 154 of file SequentialVertexFitter.h.

       {return fit(ctx, perigeeList, std::vector<const Trk::NeutralParameters*>());};

fit() [3/10]

std::unique_ptr< xAOD::Vertex > Trk::SequentialVertexFitter::fit ( const EventContext & ctx, const std::vector< const Trk::TrackParameters * > & perigeeList, const std::vector< const Trk::NeutralParameters * > & neutralPerigeeList ) const

overridevirtual

Additional fit methods.

These will later work with selected finder.. So far these methods work with default (0,0,0) starting point and "huge" diagonal error matrix

Definition at line 136 of file SequentialVertexFitter.cxx.

  {    
   
    //this method will later be modifyed to use the a finder
    //uses a default starting point so  far.
    const Amg::Vector3D start_point(0.,0.,0.);
    return fit(ctx, perigeeList, neutralPerigeeList, start_point);
 
  }

fit() [4/10]

std::unique_ptr< xAOD::Vertex > Trk::SequentialVertexFitter::fit ( const EventContext & ctx, const std::vector< const Trk::TrackParameters * > & perigeeList, const std::vector< const Trk::NeutralParameters * > & neutralPerigeeList, const Amg::Vector3D & startingPoint ) const

overridevirtual

Vertex fit from list of track and neutral parameters and a starting point.

Definition at line 98 of file SequentialVertexFitter.cxx.

  {
    xAOD::Vertex constraint;
    constraint.makePrivateStore();
    constraint.setPosition( startingPoint );
    constraint.setCovariancePosition( AmgSymMatrix(3)::Zero(3,3) );
    constraint.setFitQuality( 0.,0.);
    std::unique_ptr<xAOD::Vertex> FittedVertex = fit(ctx, perigeeList, neutralPerigeeList, constraint);
   
    //setting the initial perigees  
    if(FittedVertex !=nullptr )
    {
      if(FittedVertex->vxTrackAtVertexAvailable())
      {
        if(!FittedVertex->vxTrackAtVertex().empty())
        {
          for(unsigned int i = 0; i <perigeeList.size(); ++i)
          {
            const Trk::TrackParameters* iPer = perigeeList[i];
            (FittedVertex->vxTrackAtVertex())[i].setInitialPerigee(iPer);
          }
          //same for neutrals
          for(unsigned int i = 0; i <neutralPerigeeList.size(); ++i)      {
            const Trk::NeutralParameters* iPer = neutralPerigeeList[i];
            (FittedVertex->vxTrackAtVertex())[perigeeList.size()+i].setInitialPerigee(iPer);
          }
        } //end of protection against unsuccessfull updates (no tracks or neutrals were added)
      }
    }
 
    return FittedVertex; 
  
  }

fit() [5/10]

std::unique_ptr< xAOD::Vertex > Trk::SequentialVertexFitter::fit ( const EventContext & ctx, const std::vector< const Trk::TrackParameters * > & perigeeList, const std::vector< const Trk::NeutralParameters * > & neutralPerigeeList, const xAOD::Vertex & constraint ) const

overridevirtual

Vertex fit from the vector of track and neutral parameters with a preliminary knowledge (vertex constraint).

Definition at line 150 of file SequentialVertexFitter.cxx.

  {
 
    //security check
    if(perigeeList.empty())
    {
      ATH_MSG_INFO( "Empty vector of tracks passed, returning 0" );
      return nullptr;
    }
 
    //identifying the input parameters of the fit
    //and making initial xAOD::Vertex to be updated with tracks
    const Amg::Vector3D& priorVertexPosition = constraint.position();
    const AmgSymMatrix(3)& initialVertexError = constraint.covariancePosition();
    AmgSymMatrix(3) priorErrorMatrix;
 
    double in_chi = 0.;
    double in_ndf = 0.;
 
    bool priorInfo=false;
 
    //checking whether the prior information has a defined error matrix:
    if(initialVertexError.trace() == 0.)
    {
 
      //no prior estimate, using the huge error method
      //creating a covariance matrix:
      float diag = 1000000.0;
      AmgSymMatrix(3) in_m;
      in_m.setIdentity();
      priorErrorMatrix = in_m * diag;
 
      //   we're  now working without prior knowledge,
      //   so the effective ndf is reduced by 3.
      in_ndf-=3.;
 
    } else {
      priorInfo=true;
      priorErrorMatrix = initialVertexError;
    }
    // creating an initial vertex to update
    std::unique_ptr<xAOD::Vertex> returnVertex = std::make_unique<xAOD::Vertex>();  
    returnVertex->makePrivateStore(); // xAOD::VertexContainer will take ownership of AuxStore when returnVertex is added to it
    returnVertex->setPosition( priorVertexPosition );
    returnVertex->setCovariancePosition( priorErrorMatrix );
    returnVertex->setFitQuality( in_chi, in_ndf );
    returnVertex->setVertexType( xAOD::VxType::NotSpecified ); // to mimic the initialization present in the old EDM constructor
 
    //converting the input perigee to the Vertex tracks
    std::vector<Trk::VxTrackAtVertex> tracks_to_fit = linearizeTracks(perigeeList, neutralPerigeeList, *returnVertex);
    std::vector<Trk::VxTrackAtVertex> fittedTracks(0);
    returnVertex->vxTrackAtVertex() = std::move(fittedTracks);
 
    //the actual fitting loop
    Amg::Vector3D newPosition = returnVertex->position();
    Amg::Vector3D previousPreviousPosition = newPosition;
    Amg::Vector3D previousPosition = newPosition;
    double newChi2= returnVertex->chiSquared();
    double previousChi2{};
    unsigned int n_iter = 0;
    double deltaR{};
    bool fitFailed{false};
 
    std::vector<Trk::VxTrackAtVertex>::iterator tracksBegin = tracks_to_fit.begin();
    std::vector<Trk::VxTrackAtVertex>::iterator tracksEnd = tracks_to_fit.end();
    auto deltaChi2 = [](double chi1, double chi0){
      return std::abs((chi1-chi0)*2./(chi1+chi0+2.));
    };
    do {
      if (!priorInfo){
        returnVertex->setPosition( newPosition );
        returnVertex->setCovariancePosition( priorErrorMatrix );
        returnVertex->setFitQuality( in_chi, in_ndf );
      } else {
        returnVertex->setPosition( priorVertexPosition );
        returnVertex->setCovariancePosition( priorErrorMatrix );
        returnVertex->setFitQuality( in_chi, in_ndf );            
      }
 
      //optional relinearization
      if(n_iter !=0) {
        reLinearizeTracks(tracks_to_fit, returnVertex->position());
      }
      //loop over available tracks
 
      for(std::vector<Trk::VxTrackAtVertex>::iterator i = tracksBegin; i != tracksEnd;++i)
      {                  
        xAOD::Vertex *new_vertex = m_Updator->add(*returnVertex, *i);
        if (new_vertex != returnVertex.get()) {
            returnVertex.reset( new_vertex );
        }
      }//end of loop over available tracks
 
      //now the updated state that is stored in returnVertex
      previousPreviousPosition = previousPosition;
      previousPosition = newPosition;
      previousChi2 = newChi2;
      newPosition = returnVertex->position();
      newChi2 = returnVertex->chiSquared();
      ++n_iter;
      //the fit always fails if a negative chisquared was returned at some point or the z-coordinate of the vertex was outside ID
      fitFailed = (n_iter == m_maxStep) or (newChi2 <0.) or std::abs(returnVertex->z())>m_maxZ;
      deltaR = (previousPosition - newPosition).perp();
      // the rest after 'fitFailed' won't be evaluated if the fit failed, 
      // so hopefully no more FPE in the division
    } while ( (not fitFailed) && 
              ( ( deltaR > m_maxShift && m_useLooseConvergence )
                || ( !m_useLooseConvergence && deltaChi2(newChi2, previousChi2) > m_maxDeltaChi2 ) ) );
 
    if (fitFailed) {    
      ATH_MSG_DEBUG( " Fit failed. " );
      ATH_MSG_DEBUG( " Fit didn't converge after " << n_iter );
      ATH_MSG_DEBUG( " steps. Deltachi2: " << deltaChi2(newChi2, previousChi2) );            
      ATH_MSG_DEBUG( " DeltaR "  << deltaR); 
      returnVertex.reset();
      return nullptr;
    }
    //smoothing and related
    if(m_doSmoothing)m_Smoother->smooth(*returnVertex);
    
    //here the vertex is returned. It is foreseen that a vertex is _always_
    //returned (initial guess in worst case) unless there is a runtime crash
    return returnVertex;
 
  }//end of the actual fit method

fit() [6/10]

virtual std::unique_ptr< xAOD::Vertex > Trk::SequentialVertexFitter::fit ( const EventContext & ctx, const std::vector< const Trk::TrackParameters * > & perigeeList, const xAOD::Vertex & constraint ) const

inlineoverridevirtual

Definition at line 136 of file SequentialVertexFitter.h.

       {return fit(ctx, perigeeList, std::vector<const Trk::NeutralParameters*>(), constraint);};

fit() [7/10]

virtual std::unique_ptr< xAOD::Vertex > Trk::SequentialVertexFitter::fit ( const EventContext & ctx, const std::vector< const xAOD::TrackParticle * > & vectorTrk, const Amg::Vector3D & startingPoint ) const

inlineoverridevirtual

Interface for xAOD::TrackParticle with starting point.

Definition at line 86 of file SequentialVertexFitter.h.

       {return fit(ctx, vectorTrk, std::vector<const xAOD::NeutralParticle*>(), startingPoint);};

fit() [8/10]

std::unique_ptr< xAOD::Vertex > Trk::SequentialVertexFitter::fit ( const EventContext & ctx, const std::vector< const xAOD::TrackParticle * > & vectorTrk, const std::vector< const xAOD::NeutralParticle * > & vectorNeut, const Amg::Vector3D & startingPoint ) const

overridevirtual

Interface for xAOD::TrackParticle and xAOD::NeutralParticle with starting point.

Definition at line 365 of file SequentialVertexFitter.cxx.

 {
   xAOD::Vertex constraint;
   constraint.makePrivateStore();
   constraint.setPosition( startingPoint );
   constraint.setCovariancePosition( AmgSymMatrix(3)::Zero(3,3) );
   constraint.setFitQuality( 0.,0.);             
   return fit(ctx, vectorTrk, vectorNeut, constraint);
 }//end of the xAOD starting point fit method

fit() [9/10]

std::unique_ptr< xAOD::Vertex > Trk::SequentialVertexFitter::fit ( const EventContext & ctx, const std::vector< const xAOD::TrackParticle * > & vectorTrk, const std::vector< const xAOD::NeutralParticle * > & vectorNeut, const xAOD::Vertex & constraint ) const

overridevirtual

Interface for xAOD::TrackParticle and xAOD::NeutralParticle with vertex constraint the position of the constraint is ALWAYS the starting point.

Definition at line 376 of file SequentialVertexFitter.cxx.

 {
 
   if(vectorTrk.empty())
   {
     ATH_MSG_INFO( "Empty vector of tracks passed" );
     return nullptr;
   }
 
   if(vectorNeut.empty())
   {
     ATH_MSG_INFO( "Empty vector of neutrals passed" );
   }
   
   //making a list of perigee out of the vector of tracks
   //Also check for duplicate tracks (will otherwise be discarded by the fit); they do not
   // fit the hypothesis of statistically independent tracks. Print a warning and discard the duplicate
   // it this happens.
   std::vector<const Trk::TrackParameters*> measuredPerigees;
   std::vector<const xAOD::TrackParticle*> trkToFit;
   
   for(std::vector<const xAOD::TrackParticle*>::const_iterator i = vectorTrk.begin(); i!= vectorTrk.end();++i)
   {
     //check for duplicates
     bool foundDuplicate(false);
     for (std::vector<const xAOD::TrackParticle*>::const_iterator j = vectorTrk.begin(); j!= i; ++j) {
       if (*i == *j) {
     ATH_MSG_WARNING( "Duplicate track given as input to the fitter. Ignored." );
     foundDuplicate = true;
     break;
       }
     }
     if (foundDuplicate) continue; //skip track
 
     const Trk::TrackParameters * tmpMeasPer = &((*i)->perigeeParameters());
  
     if(tmpMeasPer!=nullptr) {
       trkToFit.push_back(*i);
       measuredPerigees.push_back(tmpMeasPer);
     } else {
       ATH_MSG_INFO( "Failed to dynamic_cast this track parameters to perigee" ); //TODO: Failed to implicit cast the perigee parameters to track parameters?
     }
   }
 
   //making a list of perigee out of the vector of neutrals
   std::vector<const Trk::NeutralParameters*> measuredNeutralPerigees;
   std::vector<const xAOD::NeutralParticle*> neutToFit;
   for(std::vector<const xAOD::NeutralParticle*>::const_iterator i = vectorNeut.begin(); i!= vectorNeut.end();++i)
   {
     //check for duplicates
     bool foundDuplicate(false);
     for (std::vector<const xAOD::NeutralParticle*>::const_iterator j = vectorNeut.begin(); j!= i; ++j) {
       if (*i == *j) {
     ATH_MSG_WARNING( "Duplicate neutral given as input to the fitter. Ignored." );
     foundDuplicate = true;
     break;
       }
     }
     if (foundDuplicate) continue; //skip track
 
     const Trk::NeutralParameters * tmpMeasPer = &((*i)->perigeeParameters());
  
     if(tmpMeasPer!=nullptr) {
       neutToFit.push_back(*i);
       measuredNeutralPerigees.push_back(tmpMeasPer);
     } else {
       ATH_MSG_INFO( "Failed to dynamic_cast this neutral parameters to perigee" ); //TODO: Failed to implicit cast the perigee parameters to neutral parameters?
     }
   }
 
 
   std::unique_ptr<xAOD::Vertex> fittedVertex = fit( ctx, measuredPerigees, measuredNeutralPerigees, constraint );
 
 
   //assigning the input tracks to the fitted vertex through vxTrackAtVertices
   if(fittedVertex ==nullptr)
   {
     return fittedVertex;
   }
 
     if( fittedVertex->vxTrackAtVertexAvailable() ) // TODO: I don't think vxTrackAtVertexAvailable() does the same thing as a null pointer check!
     {
       if(!fittedVertex->vxTrackAtVertex().empty())
       {
         for(unsigned int i = 0; i <trkToFit.size(); ++i)
         {
           
           LinkToXAODTrackParticle* linkTT= new LinkToXAODTrackParticle();
           const xAOD::TrackParticleContainer* cont = dynamic_cast< const xAOD::TrackParticleContainer* >( trkToFit[ i ]->container() );
           if(  cont )
           {
             if( ! linkTT->toIndexedElement( *cont, trkToFit[ i ]->index() ) )
             {
           ATH_MSG_WARNING( "Failed to set the EL for this particle correctly" );
         }
           } else{
             ATH_MSG_WARNING( "Failed to identify a  container for this TP" );
           }//end of the dynamic cast check 
 
 
           // vxtrackatvertex takes ownership!
           ( fittedVertex->vxTrackAtVertex() )[i].setOrigTrack(linkTT);
         }//end of loop for setting orig tracks in.
 
         for(unsigned int i = 0; i <neutToFit.size(); ++i)
         {
           LinkToXAODNeutralParticle* linkTT = new LinkToXAODNeutralParticle();
           const xAOD::NeutralParticleContainer* cont = dynamic_cast< const xAOD::NeutralParticleContainer* >( neutToFit[ i ]->container() );
           if(  cont )
           {
             if( ! linkTT->toIndexedElement( *cont, neutToFit[ i ]->index() ) )
             {
               ATH_MSG_WARNING( "Failed to set the EL for this particle correctly" );
             }
           } else{
             ATH_MSG_WARNING( "Failed to identify a  container for this NP" );
           }//end of the dynamic cast check 
 
           // vxtrackatvertex takes ownership!
           ( fittedVertex->vxTrackAtVertex() )[trkToFit.size()+i].setOrigTrack(linkTT);
         }//end of loop for setting orig neutrals in.
 
       }//end of protection against unsuccessfull updates (no tracks were added)
     }//end of vector of tracks check
 
 
   //now set links to xAOD::TrackParticles directly in the xAOD::Vertex
   unsigned int VTAVsize = (fittedVertex && fittedVertex->vxTrackAtVertexAvailable()) ? fittedVertex->vxTrackAtVertex().size() : 0 ;
   for (unsigned int i = 0 ; i < VTAVsize ; ++i)
   {
     Trk::VxTrackAtVertex* VTAV = &( fittedVertex->vxTrackAtVertex().at(i) );
     //TODO: Will this pointer really hold 0 if no VxTrackAtVertex is found?
     if (not VTAV){
       ATH_MSG_WARNING( "Trying to set link to xAOD::TrackParticle. The VxTrackAtVertex is not found" );
       continue;
     }
 
     Trk::ITrackLink* trklink = VTAV->trackOrParticleLink();
 
     // See if the trklink is to an xAOD::TrackParticle
     Trk::LinkToXAODTrackParticle* linkToXAODTP = dynamic_cast<Trk::LinkToXAODTrackParticle*>(trklink);
     if (linkToXAODTP)
     {
 
       //Now set the new link to the xAOD vertex
       fittedVertex->addTrackAtVertex(*linkToXAODTP, VTAV->weight());
 
     } else {
 
       // See if the trklink is to an xAOD::NeutralParticle
       Trk::LinkToXAODNeutralParticle* linkToXAODTPneutral = dynamic_cast<Trk::LinkToXAODNeutralParticle*>(trklink);
       if (!linkToXAODTPneutral) {
         ATH_MSG_WARNING( "Skipping track. Trying to set link to something else than xAOD::TrackParticle or xAOD::NeutralParticle." );
       } else {
         //Now set the new link to the new xAOD vertex
         fittedVertex->addNeutralAtVertex(*linkToXAODTPneutral, VTAV->weight());
       }
 
     }
   } //end of loop
 
   return fittedVertex;
 
 }//end of the xAOD constrained fit method

fit() [10/10]

virtual std::unique_ptr< xAOD::Vertex > Trk::SequentialVertexFitter::fit ( const EventContext & ctx, const std::vector< const xAOD::TrackParticle * > & vectorTrk, const xAOD::Vertex & constraint ) const

inlineoverridevirtual

Interface for xAOD::TrackParticle with vertex constraint the position of the constraint is ALWAYS the starting point.

Definition at line 103 of file SequentialVertexFitter.h.

       {return fit(ctx, vectorTrk, std::vector<const xAOD::NeutralParticle*>(), constraint);};

initialize()

StatusCode Trk::SequentialVertexFitter::initialize ( )

overridevirtual

Definition at line 35 of file SequentialVertexFitter.cxx.

 {
  
//uploading the corresponding tools
 
//updator 
  ATH_CHECK( m_Updator.retrieve() ); 
  
//smoother
  ATH_CHECK( m_Smoother.retrieve( EnableTool {m_doSmoothing} ) );
 
//Linearized Track Factory 
  ATH_CHECK( m_LinTrkFactory.retrieve() );
  return StatusCode::SUCCESS;
 }//end of initialize method

linearizeTracks()

std::vector< Trk::VxTrackAtVertex > Trk::SequentialVertexFitter::linearizeTracks ( const std::vector< const Trk::TrackParameters * > & perigeeList, const std::vector< const Trk::NeutralParameters * > & neutralPerigeeList, const xAOD::Vertex & vrt ) const

private

Internal method related to the linearization of tracks (initial linearization).

Definition at line 280 of file SequentialVertexFitter.cxx.

  {
 
    //defining the output vector
    std::vector<Trk::VxTrackAtVertex> out_tracks(0);
    for(const auto *i : perigeeList)
    {
  
      //creating new meas perigees, since the will be deleted 
      //by VxTrackAtVertex in destructor
      const Trk::Perigee * loc_per = dynamic_cast<const Trk::Perigee *>(i);
      if( loc_per != nullptr)
      {
        Trk::Perigee * mPer = new Trk::Perigee(*loc_per);
        const Trk::Perigee * inPer = loc_per;
        //new MeasuredPerigee(*loc_per);
        Trk::VxTrackAtVertex * vTrack = new Trk::VxTrackAtVertex(0., mPer, nullptr, inPer, nullptr);
 
        //linearization itself
        m_LinTrkFactory->linearize( *vTrack, vrt.position() );
        vTrack->setWeight(1.);
 
        out_tracks.push_back(*vTrack);
 
        // Added the following line during EDM Migration
        delete vTrack; //TODO: is this ok? 
      } else {
        ATH_MSG_WARNING( "Cannot linearize tracks; treatment of neutrals not yet supported" );
      }
    }//end of loop over all the perigee states
 
    //same for neutrals
    for(const auto *i : neutralPerigeeList)
    {
 
      //creating new meas perigees, since the will be deleted
      //by VxTrackAtVertex in destructor
      const Trk::NeutralPerigee * loc_per = dynamic_cast<const Trk::NeutralPerigee *>(i);
      if( loc_per != nullptr)
      {
        Trk::NeutralPerigee * mPer  = new Trk::NeutralPerigee(*loc_per);
        const Trk::NeutralPerigee * inPer = loc_per;
        Trk::VxTrackAtVertex * vTrack = new Trk::VxTrackAtVertex(0., nullptr, mPer, nullptr, inPer);
 
        //linearization itself
        m_LinTrkFactory->linearize( *vTrack, vrt.position() );
        vTrack->setWeight(1.);
 
        out_tracks.push_back(*vTrack);
 
        // Added the following line during EDM Migration
        delete vTrack; //TODO: is this ok?
      } else {
        ATH_MSG_WARNING( "Cannot linearize tracks; treatment of neutrals not yet supported" );
      }
    }//end of loop over all the neutral perigee states
 
    return out_tracks;
  }//end of linearize method

reLinearizeTracks()

void Trk::SequentialVertexFitter::reLinearizeTracks ( std::vector< Trk::VxTrackAtVertex > & tracks, const Amg::Vector3D & vrt ) const

private

Relinearization on iterations.

Definition at line 343 of file SequentialVertexFitter.cxx.

 {
   Amg::Vector3D linVertexPos = vrt;
   if ( linVertexPos.perp() > m_maxR || std::abs(linVertexPos.z()) > m_maxZ )
   {
     ATH_MSG_DEBUG( " Linearization position outside ID. Setting back to (0,0,0) " );
     linVertexPos.x()=0;
     linVertexPos.y()=0;
     linVertexPos.z()=0;
   }
 
   std::vector<Trk::VxTrackAtVertex>& out_tracks = tracks;
   std::vector<Trk::VxTrackAtVertex>::iterator i_end = out_tracks.end();
   for(std::vector<Trk::VxTrackAtVertex>::iterator i = out_tracks.begin(); i!=i_end; ++i)
   {
     m_LinTrkFactory->linearize(*i,linVertexPos);
   }//end of loop over all tracks
 }//end of relinearize method

Member Data Documentation

m_doSmoothing

bool Trk::SequentialVertexFitter::m_doSmoothing

private

Flag controlling optional smoothing.

Definition at line 185 of file SequentialVertexFitter.h.

m_LinTrkFactory

ToolHandle< Trk::IVertexLinearizedTrackFactory > Trk::SequentialVertexFitter::m_LinTrkFactory

private

Definition at line 179 of file SequentialVertexFitter.h.

m_maxDeltaChi2

float Trk::SequentialVertexFitter::m_maxDeltaChi2

private

Max DeltaChi2 allowed in hard convergence criterium.

Definition at line 209 of file SequentialVertexFitter.h.

m_maxR

double Trk::SequentialVertexFitter::m_maxR

private

Definition at line 215 of file SequentialVertexFitter.h.

m_maxShift

float Trk::SequentialVertexFitter::m_maxShift

private

Max shift (represents the convergence criterion).

Definition at line 197 of file SequentialVertexFitter.h.

m_maxStep

unsigned int Trk::SequentialVertexFitter::m_maxStep

private

Max number of iterations to perform (in case of no convergence).

Definition at line 191 of file SequentialVertexFitter.h.

m_maxZ

double Trk::SequentialVertexFitter::m_maxZ

private

Definition at line 216 of file SequentialVertexFitter.h.

m_Smoother

ToolHandle< IVertexSmoother > Trk::SequentialVertexFitter::m_Smoother

private

Definition at line 178 of file SequentialVertexFitter.h.

m_Updator

ToolHandle< IVertexUpdator > Trk::SequentialVertexFitter::m_Updator

private

Definition at line 177 of file SequentialVertexFitter.h.

m_useLooseConvergence

bool Trk::SequentialVertexFitter::m_useLooseConvergence

private

Use loose convergence criterium (maxShift) or hard (+maxDeltaChi2).

Definition at line 203 of file SequentialVertexFitter.h.

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

• SequentialVertexFitter.h
• SequentialVertexFitter.cxx