Trk::ZScanSeedFinder Class Reference

#include <ZScanSeedFinder.h>

Inheritance diagram for Trk::ZScanSeedFinder:

Collaboration diagram for Trk::ZScanSeedFinder:

Classes
struct	Cache

Public Member Functions
	ZScanSeedFinder (const std::string &t, const std::string &n, const IInterface *p)
virtual	~ZScanSeedFinder ()
virtual StatusCode	initialize () override
virtual StatusCode	finalize () override
virtual Amg::Vector3D	findSeed (const std::vector< const Trk::Track * > &vectorTrk, const xAOD::Vertex *constraint=0) const override final
	Finds a linearization point out of a vector of tracks and returns it as an Amg::Vector3D object.
virtual Amg::Vector3D	findSeed (const std::vector< const Trk::TrackParameters * > &perigeeList, const xAOD::Vertex *constraint=0) const override final
	Finds a linearization point out of a vector of TrackParameters and returns it as an Amg::Vector3D object.
virtual std::vector< Amg::Vector3D >	findMultiSeeds (const std::vector< const Trk::Track * > &vectorTrk, const xAOD::Vertex *constraint=0) const override final
	Finds full vector of linearization points from a vector of tracks and returns it as an Amg::Vector3D object.
virtual std::vector< Amg::Vector3D >	findMultiSeeds (const std::vector< const Trk::TrackParameters * > &perigeeList, const xAOD::Vertex *constraint=0) const override final
	Finds full vector of linearization points from a vector of TrackParameters and returns it as an Amg::Vector3D object.
virtual Amg::Vector3D	findSeed (const double, const double, const std::vector< const Trk::TrackParameters * > &perigeeList, const xAOD::Vertex *constraint=0) const
	Finds a linearization point out of a vector of TrackParameters and returns it as an Amg::Vector3D object.
virtual Amg::Vector3D	findSeed (const double, const double, std::unique_ptr< Trk::IMode3dInfo > &, const std::vector< const Trk::TrackParameters * > &perigeeList, const xAOD::Vertex *constraint=0) const
	Finds a linearization point out of a vector of TrackParameters and returns it as an Amg::Vector3D object.

Private Member Functions
std::pair< double, double >	estimateWeight (const Trk::Perigee &iTrk, const xAOD::Vertex *constraint) const
	Estimate z-position and weight for one track.
std::vector< Trk::DoubleAndWeight >	getPositionsUncached (const std::vector< const Trk::TrackParameters * > &perigeeList, const xAOD::Vertex *constraint) const
std::vector< Trk::DoubleAndWeight >	getPositionsCached (const std::vector< const Trk::TrackParameters * > &perigeeList, const xAOD::Vertex *constraint) const

Private Attributes
SG::ReadHandleKey< xAOD::EventInfo >	m_eventInfoKey
ToolHandle< IMode1dFinder >	m_mode1dfinder
ToolHandle< ITrackToVertexIPEstimator >	m_IPEstimator
bool	m_disableAllWeights
float	m_constraintcutoff
float	m_constrainttemp
bool	m_useLogPt
double	m_minPt
bool	m_usePt
double	m_expPt
bool	m_cacheWeights
SG::SlotSpecificObj< Cache > m_cache	ATLAS_THREAD_SAFE

Detailed Description

Definition at line 46 of file ZScanSeedFinder.h.

Constructor & Destructor Documentation

ZScanSeedFinder()

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

Definition at line 26 of file ZScanSeedFinder.cxx.

                                                                                               :
    base_class(t,n,p),
    m_disableAllWeights(false),
    m_constraintcutoff(9.),
    m_constrainttemp(1.),
    m_useLogPt(true),
    m_minPt(400.),
    m_usePt(false),
    m_expPt(1.),
    m_cacheWeights(true)
  {
    declareProperty("disableAllWeights", m_disableAllWeights);
    declareProperty("constrainttemp", m_constrainttemp);
    declareProperty("constraintcutoff", m_constraintcutoff);
    declareProperty("UsePt", m_usePt);
    declareProperty("ExpPt", m_expPt);
    declareProperty("UseLogPt", m_useLogPt);
    declareProperty("MinPt", m_minPt);
    declareProperty("CacheWeights", m_cacheWeights);
  }

~ZScanSeedFinder()

Trk::ZScanSeedFinder::~ZScanSeedFinder ( )

virtualdefault

Member Function Documentation

estimateWeight()

std::pair< double, double > Trk::ZScanSeedFinder::estimateWeight ( const Trk::Perigee & iTrk, const xAOD::Vertex * constraint ) const

private

Estimate z-position and weight for one track.

Definition at line 220 of file ZScanSeedFinder.cxx.

  {
    // protect against overflow in exponential function
    static const double maxExpArg = log(std::numeric_limits<double>::max()/1.1);
 
    std::unique_ptr<const Trk::ImpactParametersAndSigma> ipas;
    if (constraint != nullptr && constraint->covariancePosition()(0,0)!=0) {
      ipas = std::unique_ptr<const Trk::ImpactParametersAndSigma> (m_IPEstimator->estimate (&iTrk, constraint));
    }
 
    std::pair<double, double> z0AndWeight;
    if (ipas != nullptr && ipas->sigmad0 > 0)
    {
      z0AndWeight.first = ipas->IPz0 + constraint->position().z();
      double chi2IP = std::pow(ipas->IPd0/ipas->sigmad0, 2);
      ATH_MSG_VERBOSE("d0 from tool: " << ipas->IPd0 << " error: " << ipas->sigmad0 << " chi2: " << chi2IP);
      if ( !m_disableAllWeights )
      {
        z0AndWeight.second = 1./(1.+exp(std::min((chi2IP-m_constraintcutoff)/m_constrainttemp, maxExpArg)));
      }
      else
      {
        z0AndWeight.second = 1.;
      }
    }
    else
    {
      if (constraint != nullptr) ATH_MSG_WARNING("Unable to compute impact parameter significance; setting IPWeight = 1");
      z0AndWeight.first = iTrk.position()[Trk::z];
      z0AndWeight.second = 1.;
    }
 
    // apply pT weighting as/if configured
    if (!m_disableAllWeights && ( m_usePt || m_useLogPt) )
    {
      double Pt = fabs(1./iTrk.parameters()[Trk::qOverP])*sin(iTrk.parameters()[Trk::theta]);
      if ( m_usePt )
      {
        z0AndWeight.second *= std::pow(Pt, m_expPt);
      }
      else
      {
        z0AndWeight.second *= log(std::max(Pt / m_minPt, 1.001));
      }
    }
 
    return z0AndWeight;
  }

finalize()

StatusCode Trk::ZScanSeedFinder::finalize ( )

overridevirtual

Definition at line 74 of file ZScanSeedFinder.cxx.

  {
    ATH_MSG_DEBUG("Finalize successful");
    return StatusCode::SUCCESS;
  }

findMultiSeeds() [1/2]

std::vector< Amg::Vector3D > Trk::ZScanSeedFinder::findMultiSeeds ( const std::vector< const Trk::Track * > & vectorTrk, const xAOD::Vertex * constraint = 0 ) const

finaloverridevirtual

Finds full vector of linearization points from a vector of tracks and returns it as an Amg::Vector3D object.

Intended for seed finders that produce all at once. If you want an additional constraint can be taken into account.

Definition at line 271 of file ZScanSeedFinder.cxx.

                                                                                                                       {
 
    //implemented to satisfy inheritance but this algorithm only supports one seed at a time
    ATH_MSG_WARNING("Multi-seeding requested but seed finder not able to operate in that mode, returning no seeds");
    return std::vector<Amg::Vector3D>(0);
 
  }

findMultiSeeds() [2/2]

std::vector< Amg::Vector3D > Trk::ZScanSeedFinder::findMultiSeeds ( const std::vector< const Trk::TrackParameters * > & perigeeList, const xAOD::Vertex * constraint = 0 ) const

finaloverridevirtual

Finds full vector of linearization points from a vector of TrackParameters and returns it as an Amg::Vector3D object.

Intended for seed finders that produce all at once. If you want an additional constraint can be taken into account.

Definition at line 280 of file ZScanSeedFinder.cxx.

                                                                                                                                 {
 
    //implemented to satisfy inheritance but this algorithm only supports one seed at a time
    ATH_MSG_WARNING("Multi-seeding requested but seed finder not able to operate in that mode, returning no seeds");
    return std::vector<Amg::Vector3D>(0);
 
  }

findSeed() [1/4]

virtual Amg::Vector3D Trk::IVertexSeedFinder::findSeed ( const double , const double , const std::vector< const Trk::TrackParameters * > & perigeeList, const xAOD::Vertex * constraint = 0 ) const

inline

Finds a linearization point out of a vector of TrackParameters and returns it as an Amg::Vector3D object.

If you want an additional constraint can be taken into account. Must specify the primary vertex position.

Definition at line 79 of file IVertexSeedFinder.h.

    {
      return findSeed (perigeeList, constraint);
    }

findSeed() [2/4]

virtual Amg::Vector3D Trk::IVertexSeedFinder::findSeed ( const double , const double , std::unique_ptr< Trk::IMode3dInfo > & , const std::vector< const Trk::TrackParameters * > & perigeeList, const xAOD::Vertex * constraint = 0 ) const

inline

Finds a linearization point out of a vector of TrackParameters and returns it as an Amg::Vector3D object.

If you want an additional constraint can be taken into account. Must specify the primary vertex position. Allows returning additional diagnostic information.

Definition at line 96 of file IVertexSeedFinder.h.

    {
      return findSeed (perigeeList, constraint);
    }

findSeed() [3/4]

Amg::Vector3D Trk::ZScanSeedFinder::findSeed ( const std::vector< const Trk::Track * > & vectorTrk, const xAOD::Vertex * constraint = 0 ) const

finaloverridevirtual

Finds a linearization point out of a vector of tracks and returns it as an Amg::Vector3D object.

If you want an additional constraint can be taken into account.

Definition at line 81 of file ZScanSeedFinder.cxx.

                                                                                                                        {
 
    //create perigees from track list
    std::vector<const TrackParameters*> perigeeList;
 
    std::vector<const Trk::Track*>::const_iterator begin=VectorTrk.begin();
    std::vector<const Trk::Track*>::const_iterator end=VectorTrk.end();
 
    for (std::vector<const Trk::Track*>::const_iterator iter=begin;
     iter!=end;++iter)
    {
      if (std::isnan((*iter)->perigeeParameters()->parameters()[Trk::d0]))
      {
    continue;
      }
      perigeeList.push_back((*iter)->perigeeParameters());
    }
 
    //create seed from perigee list
    return findSeed(perigeeList,constraint);
 
  }

findSeed() [4/4]

Amg::Vector3D Trk::ZScanSeedFinder::findSeed ( const std::vector< const Trk::TrackParameters * > & perigeeList, const xAOD::Vertex * constraint = 0 ) const

finaloverridevirtual

Finds a linearization point out of a vector of TrackParameters and returns it as an Amg::Vector3D object.

If you want an additional constraint can be taken into account.

Definition at line 104 of file ZScanSeedFinder.cxx.

                                                                                                                                    {
 
 
    double ZResult=0.;
    std::vector<Trk::DoubleAndWeight> ZPositions;
    if (m_cacheWeights) {
      ZPositions = getPositionsCached (perigeeList, constraint);
    }
    else {
      ZPositions = getPositionsUncached (perigeeList, constraint);
    }
 
    if ( !ZPositions.empty() )
    {
    ZResult=m_mode1dfinder->getMode(ZPositions);
        ATH_MSG_DEBUG("Resulting mean Z position found: " << ZResult);
    }
    else
    {
      ATH_MSG_DEBUG("No tracks with sufficient weight; return z position = 0");
    }
 
    if (constraint)
    {
      return Amg::Vector3D(constraint->position().x(),constraint->position().y(),ZResult);
    }
    return Amg::Vector3D(0.,0.,ZResult);
 
  }

getPositionsCached()

std::vector< Trk::DoubleAndWeight > Trk::ZScanSeedFinder::getPositionsCached ( const std::vector< const Trk::TrackParameters * > & perigeeList, const xAOD::Vertex * constraint ) const

private

Definition at line 166 of file ZScanSeedFinder.cxx.

  {
    const EventContext& ctx = Gaudi::Hive::currentContext();
    Cache& cache = *m_cache;
 
    Amg::Vector2D constraintkey;
    if (constraint) {
      constraintkey.x() = constraint->position().x();
      constraintkey.y() = constraint->position().y();
    }
    else {
      constraintkey.x() = std::numeric_limits<double>::max();
      constraintkey.y() = std::numeric_limits<double>::min();
    }
 
    std::vector<Trk::DoubleAndWeight> ZPositions;
 
    std::lock_guard<std::mutex> lock (cache.m_mutex);
    if (ctx.evt() != cache.m_evt) {
      cache.m_weightMap.clear();
    }
 
    for (const Trk::TrackParameters* i : perigeeList)
    {
      const Perigee* iTrk = dynamic_cast<const Trk::Perigee*>(i);
      if (iTrk == nullptr)
      {
      ATH_MSG_WARNING("Neutrals not supported for seeding. Rejecting track...");
      continue;
      }
 
      Cache::key_t key (*iTrk, constraintkey);
      auto [it, flag] = cache.m_weightMap.try_emplace (key, Cache::value_t());
      if (flag) {
        it->second = estimateWeight (*iTrk, constraint);
        ATH_MSG_DEBUG("Found position z: " << it->second.first <<
                      " with weight " << it->second.second);
      }
 
      if (it->second.second >= 0.01)
      {
    ZPositions.push_back (it->second);
      }
    }
 
    return ZPositions;
  }

getPositionsUncached()

std::vector< Trk::DoubleAndWeight > Trk::ZScanSeedFinder::getPositionsUncached ( const std::vector< const Trk::TrackParameters * > & perigeeList, const xAOD::Vertex * constraint ) const

private

Definition at line 136 of file ZScanSeedFinder.cxx.

  {
    std::vector<Trk::DoubleAndWeight> ZPositions;
 
    for (const Trk::TrackParameters* i : perigeeList)
    {
      const Perigee* iTrk = dynamic_cast<const Trk::Perigee*>(i);
      if (iTrk == nullptr)
      {
      ATH_MSG_WARNING("Neutrals not supported for seeding. Rejecting track...");
      continue;
      }
 
      std::pair<double, double> z0AndWeight =
        estimateWeight (*iTrk, constraint);
      ATH_MSG_DEBUG("Found position z: " << z0AndWeight.first <<
                    " with weight " << z0AndWeight.second);
 
      if (z0AndWeight.second >= 0.01)
      {
    ZPositions.push_back(z0AndWeight);
      }
    }
 
    return ZPositions;
  }

initialize()

StatusCode Trk::ZScanSeedFinder::initialize ( )

overridevirtual

Definition at line 52 of file ZScanSeedFinder.cxx.

  {
    ATH_CHECK( m_eventInfoKey.initialize() );
    if ( m_mode1dfinder.retrieve().isFailure() ) {
      ATH_MSG_FATAL("Failed to retrieve tool " << m_mode1dfinder);
      return StatusCode::FAILURE;
    } else if ( m_IPEstimator.retrieve().isFailure() ) {
      ATH_MSG_FATAL("Failed to retrieve tool " << m_IPEstimator);
    } else {
      ATH_MSG_INFO("Retrieved tools " << m_mode1dfinder << " and " << m_IPEstimator);
    }
 
    if ( m_usePt && m_useLogPt )
    {
      ATH_MSG_FATAL("At most one of Pt and LogPt weighting may be selected");
      return StatusCode::FAILURE;
    }
 
    ATH_MSG_DEBUG("Initialize successful");
    return StatusCode::SUCCESS;
  }

Member Data Documentation

ATLAS_THREAD_SAFE

SG::SlotSpecificObj<Cache> m_cache Trk::ZScanSeedFinder::ATLAS_THREAD_SAFE

mutableprivate

Definition at line 193 of file ZScanSeedFinder.h.

m_cacheWeights

bool Trk::ZScanSeedFinder::m_cacheWeights

private

Definition at line 144 of file ZScanSeedFinder.h.

m_constraintcutoff

float Trk::ZScanSeedFinder::m_constraintcutoff

private

Definition at line 138 of file ZScanSeedFinder.h.

m_constrainttemp

float Trk::ZScanSeedFinder::m_constrainttemp

private

Definition at line 139 of file ZScanSeedFinder.h.

m_disableAllWeights

bool Trk::ZScanSeedFinder::m_disableAllWeights

private

Definition at line 137 of file ZScanSeedFinder.h.

m_eventInfoKey

SG::ReadHandleKey<xAOD::EventInfo> Trk::ZScanSeedFinder::m_eventInfoKey

private

Initial value:

{
      this,
      "EventInfo",
      "EventInfo",
      "key for EventInfo retrieval"
    }

Definition at line 120 of file ZScanSeedFinder.h.

                                                 {
      this,
      "EventInfo",
      "EventInfo",
      "key for EventInfo retrieval"
    };

m_expPt

double Trk::ZScanSeedFinder::m_expPt

private

Definition at line 143 of file ZScanSeedFinder.h.

m_IPEstimator

ToolHandle<ITrackToVertexIPEstimator> Trk::ZScanSeedFinder::m_IPEstimator

private

Initial value:

{
      this,
      "IPEstimator",
      "Trk::TrackToVertexIPEstimator"
    }

Definition at line 131 of file ZScanSeedFinder.h.

                                                       {
      this,
      "IPEstimator",
      "Trk::TrackToVertexIPEstimator"
    };

m_minPt

double Trk::ZScanSeedFinder::m_minPt

private

Definition at line 141 of file ZScanSeedFinder.h.

m_mode1dfinder

ToolHandle<IMode1dFinder> Trk::ZScanSeedFinder::m_mode1dfinder

private

Initial value:

{ this,
                                              "Mode1dFinder",
                                              "Trk::FsmwMode1dFinder" }

Definition at line 127 of file ZScanSeedFinder.h.

                                            { this,
                                              "Mode1dFinder",
                                              "Trk::FsmwMode1dFinder" };

m_useLogPt

bool Trk::ZScanSeedFinder::m_useLogPt

private

Definition at line 140 of file ZScanSeedFinder.h.

m_usePt

bool Trk::ZScanSeedFinder::m_usePt

private

Definition at line 142 of file ZScanSeedFinder.h.

---

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

• ZScanSeedFinder.h
• ZScanSeedFinder.cxx