AxialTrackMerger Class Reference

Findlet implementing the merging of axial tracks found in the legendre tree search. More...

#include <AxialTrackMerger.h>

Inheritance diagram for AxialTrackMerger:

Collaboration diagram for AxialTrackMerger:

Public Types
using	IOTypes = std::tuple< AIOTypes... >
	Types that should be served to apply on invokation.
using	IOVectors = std::tuple< std::vector< AIOTypes >... >
	Vector types that should be served to apply on invokation.

Public Member Functions
std::string	getDescription () final
	Short description of the findlet.
void	exposeParameters (ModuleParamList *moduleParamList, const std::string &prefix) final
	Expose the parameters to a module.
void	apply (std::vector< CDCTrack > &axialTracks, const std::vector< const CDCWireHit * > &axialWireHits) final
	Merge tracks together. Allows for axial hits to be added as it may see fit.
virtual void	apply (ToVector< AIOTypes > &... ioVectors)=0
	Main function executing the algorithm.
void	initialize () override
	Receive and dispatch signal before the start of the event processing.
void	beginRun () override
	Receive and dispatch signal for the beginning of a new run.
void	beginEvent () override
	Receive and dispatch signal for the start of a new event.
void	endRun () override
	Receive and dispatch signal for the end of the run.
void	terminate () override
	Receive and dispatch Signal for termination of the event processing.

Protected Types
template<class T >
using	ToVector = typename ToVectorImpl< T >::Type
	Short hand for ToRangeImpl.

Protected Member Functions
void	addProcessingSignalListener (ProcessingSignalListener *psl)
	Register a processing signal listener to be notified.
int	getNProcessingSignalListener ()
	Get the number of currently registered listeners.

Private Types
using	Super = Findlet< CDCTrack &, const CDCWireHit *const >
	Type of the base class.

Private Member Functions
void	doTracksMerging (std::vector< CDCTrack > &axialTracks, const std::vector< const CDCWireHit * > &allAxialWireHits)
	The track finding often finds two curling tracks, originating from the same particle.

Static Private Member Functions
template<class ACDCTracks >
static WithWeight< MayBePtr< CDCTrack > >	calculateBestTrackToMerge (CDCTrack &track, ACDCTracks &tracks)
	Searches for the best candidate to merge this track to.
static double	doTracksFitTogether (CDCTrack &track1, CDCTrack &track2)
	Fits the hit content of both tracks in a common fit repeated with an annealing schedule removing far away hits.
static void	removeStrangeHits (double factor, std::vector< const CDCWireHit * > &wireHits, CDCTrajectory2D &trajectory)
	Remove all hits that are further than factor * driftlength away from the trajectory.
static void	mergeTracks (CDCTrack &track1, CDCTrack &track2, const std::vector< const CDCWireHit * > &allAxialWireHits)
	Function to merge two track candidates.

Private Attributes
double	m_param_minFitProb = 0.85
	Parameter : Minimal fit probability of the common fit of two tracks to be eligible for merging.
std::vector< ProcessingSignalListener * >	m_subordinaryProcessingSignalListeners
	References to subordinary signal processing listener contained in this findlet.
bool	m_initialized = false
	Flag to keep track whether initialization happend before.
bool	m_terminated = false
	Flag to keep track whether termination happend before.
std::string	m_initializedAs
	Name of the type during initialisation.

Detailed Description

Findlet implementing the merging of axial tracks found in the legendre tree search.

Definition at line 30 of file AxialTrackMerger.h.

Member Typedef Documentation

IOTypes

using IOTypes = std::tuple<AIOTypes...>

inherited

Types that should be served to apply on invokation.

Definition at line 30 of file Findlet.h.

IOVectors

using IOVectors = std::tuple< std::vector<AIOTypes>... >

inherited

Vector types that should be served to apply on invokation.

Definition at line 53 of file Findlet.h.

Super

using Super = Findlet<CDCTrack&, const CDCWireHit* const>

private

Type of the base class.

Definition at line 34 of file AxialTrackMerger.h.

ToVector

using ToVector = typename ToVectorImpl<T>::Type

protectedinherited

Short hand for ToRangeImpl.

Definition at line 49 of file Findlet.h.

Member Function Documentation

addProcessingSignalListener()

void addProcessingSignalListener ( ProcessingSignalListener *  psl )

protectedinherited

Register a processing signal listener to be notified.

Definition at line 55 of file CompositeProcessingSignalListener.cc.

{
  m_subordinaryProcessingSignalListeners.push_back(psl);
}

apply()

void apply ( std::vector< CDCTrack > &  axialTracks, const std::vector< const CDCWireHit * > &  axialWireHits  )

final

Merge tracks together. Allows for axial hits to be added as it may see fit.

Definition at line 41 of file AxialTrackMerger.cc.

{
  // Check quality of the track basing on holes on the trajectory;
  // if holes exist then track is splitted
  for (CDCTrack& track : axialTracks) {
    if (track.size() < 5) continue;
    AxialTrackUtil::removeHitsAfterSuperLayerBreak(track);
    AxialTrackUtil::normalizeTrack(track);
  }
 
  // Update tracks before storing to DataStore
  for (CDCTrack& track : axialTracks) {
    AxialTrackUtil::normalizeTrack(track);
  }
 
  // Remove bad tracks
  AxialTrackUtil::deleteShortTracks(axialTracks);
  AxialTrackUtil::deleteTracksWithLowFitProbability(axialTracks);
 
  // Perform tracks merging
  this->doTracksMerging(axialTracks, allAxialWireHits);
 
  // Remove the consumed, now empty tracks.
  AxialTrackUtil::deleteShortTracks(axialTracks, 0);
}

beginEvent()

void beginEvent ( )

overridevirtualinherited

Receive and dispatch signal for the start of a new event.

Reimplemented from ProcessingSignalListener.

Reimplemented in SpacePointTagger< Belle2::CKFToPXDResult, Belle2::PXDCluster >, SpacePointTagger< Belle2::CKFToSVDResult, Belle2::SVDCluster >, BaseEventTimeExtractor< RecoTrack * >, BaseEventTimeExtractor< TrackFindingCDC::CDCWireHit & >, SharingHitsMatcher< Belle2::TrackFindingCDC::CDCTrack, Belle2::TrackFindingCDC::CDCSegment2D >, MCSymmetric< BaseAxialSegmentPairFilter >, MCSymmetric< BaseFacetFilter >, MCSymmetric< BaseFacetRelationFilter >, MCSymmetric< BaseSegmentPairFilter >, MCSymmetric< BaseSegmentPairRelationFilter >, MCSymmetric< BaseSegmentRelationFilter >, MCSymmetric< BaseSegmentTripleFilter >, MCSymmetric< BaseSegmentTripleRelationFilter >, MCSymmetric< BaseTrackRelationFilter >, StoreVectorSwapper< Belle2::TrackFindingCDC::CDCFacet >, StoreVectorSwapper< Belle2::TrackFindingCDC::CDCWireHit, true >, StoreVectorSwapper< Belle2::TrackFindingCDC::CDCSegment2D >, StoreVectorSwapper< Belle2::TrackFindingCDC::CDCTrack >, StoreVectorSwapper< Belle2::TrackFindingCDC::CDCSegmentPair >, StoreVectorSwapper< Belle2::TrackFindingCDC::CDCSegmentTriple >, RecoTrackStorer, ROIFinder, and SVDHoughTracking.

Definition at line 31 of file CompositeProcessingSignalListener.cc.

{
  Super::beginEvent();
  for (ProcessingSignalListener* psl : m_subordinaryProcessingSignalListeners) {
    psl->beginEvent();
  }
}

beginRun()

void beginRun ( )

overridevirtualinherited

Receive and dispatch signal for the beginning of a new run.

Reimplemented from ProcessingSignalListener.

Reimplemented in LayerRelationFilter< AFilter >, FourHitFilter, QualityIndicatorFilter, ThreeHitFilter, TwoHitVirtualIPFilter, TwoHitVirtualIPQIFilter, RecoTrackStorer, ROIFinder, SpacePointLoaderAndPreparer, and TrackCandidateResultRefiner.

Definition at line 23 of file CompositeProcessingSignalListener.cc.

{
  Super::beginRun();
  for (ProcessingSignalListener* psl : m_subordinaryProcessingSignalListeners) {
    psl->beginRun();
  }
}

calculateBestTrackToMerge()

WithWeight< MayBePtr< CDCTrack > > calculateBestTrackToMerge ( CDCTrack &  track, ACDCTracks &  tracks  )

staticprivate

Searches for the best candidate to merge this track to.

Determine the best track for merging with the candidate track.

Parameters

track	track for which we try to find merging partner
tracks	search range of tracks

Returns

a pointer to the best fit candidate including a fit probability

Return values

{nullptr,0}

in case no match was found

Definition at line 89 of file AxialTrackMerger.cc.

{
  std::vector<WithWeight<CDCTrack*>> weightedTracks;
  for (CDCTrack& track2 : tracks) {
    if (&track == &track2) continue;
    if (track2.size() < 3) continue;
 
    double fitProb = doTracksFitTogether(track, track2);
    if (std::isnan(fitProb)) continue;
 
    weightedTracks.emplace_back(&track2, fitProb);
  }
 
  auto bestMatch = std::max_element(weightedTracks.begin(), weightedTracks.end(), LessWeight());
  if (bestMatch == weightedTracks.end()) return {nullptr, 0};
  else return *bestMatch;
}

doTracksFitTogether()

double doTracksFitTogether ( CDCTrack &  track1, CDCTrack &  track2  )

staticprivate

Fits the hit content of both tracks in a common fit repeated with an annealing schedule removing far away hits.

Returns

Some measure of fit probability

Definition at line 107 of file AxialTrackMerger.cc.

{
  // First check whether most of the hits from the tracks lie in the backward direction
  // even if though track is not curling -> tracks should not be merged
  const CDCTrajectory3D& trajectory3D1 = track1.getStartTrajectory3D();
  const CDCTrajectory3D& trajectory3D2 = track2.getStartTrajectory3D();
 
  const Vector2D& phi0Vec1 = trajectory3D1.getFlightDirection3DAtSupport().xy();
  const Vector2D& phi0Vec2 = trajectory3D2.getFlightDirection3DAtSupport().xy();
 
  int fbVote12 = 0;
  int fbVote21 = 0;
 
  for (const CDCRecoHit3D& recoHit3D : track1) {
    EForwardBackward fbInfo = phi0Vec2.isForwardOrBackwardOf(recoHit3D.getRecoPos2D());
    if (not isValid(fbInfo)) continue;
    fbVote12 += fbInfo;
  }
 
  for (const CDCRecoHit3D& recoHit3D : track2) {
    EForwardBackward fbInfo = phi0Vec1.isForwardOrBackwardOf(recoHit3D.getRecoPos2D());
    if (not isValid(fbInfo)) continue;
    fbVote21 += fbInfo;
  }
 
  if (not trajectory3D1.isCurler() and fbVote12 < 0) return NAN;
  if (not trajectory3D2.isCurler() and fbVote21 < 0) return NAN;
 
  // Build common hit list by copying the wire hits into one large list
  // We use the wire hits here as we do not want them to bring
  // their "old" reconstructed position when fitting.
  std::vector<const CDCWireHit*> combinedWireHits;
  combinedWireHits.reserve(track1.size() + track2.size());
  for (const CDCRecoHit3D& hit : track1) {
    combinedWireHits.push_back(&(hit.getWireHit()));
  }
  for (const CDCRecoHit3D& hit : track2) {
    combinedWireHits.push_back(&(hit.getWireHit()));
  }
 
  // Sorting is done via pointer addresses (!!).
  // This is not very stable and also not very meaningful (in terms of ordering in the track),
  // but it does the job for unique.
  // (the ordering is still outwards though since the wire hits are ordered like that in continuous memory)
  std::sort(combinedWireHits.begin(), combinedWireHits.end());
  erase_unique(combinedWireHits);
 
  // Calculate track parameters
  CDCTrajectory2D commonTrajectory2D;
  const CDCKarimakiFitter& fitter = CDCKarimakiFitter::getNoDriftVarianceFitter();
 
  // Approach the best fit
  commonTrajectory2D = fitter.fit(combinedWireHits);
  removeStrangeHits(5, combinedWireHits, commonTrajectory2D);
  commonTrajectory2D = fitter.fit(combinedWireHits);
  removeStrangeHits(3, combinedWireHits, commonTrajectory2D);
  commonTrajectory2D = fitter.fit(combinedWireHits);
  removeStrangeHits(1, combinedWireHits, commonTrajectory2D);
  commonTrajectory2D = fitter.fit(combinedWireHits);
  removeStrangeHits(1, combinedWireHits, commonTrajectory2D);
  commonTrajectory2D = fitter.fit(combinedWireHits);
 
  // Dismiss this possibility if the hit list size after all the removing of hits is even smaller
  // than the two lists before or if the list is too small
  if (combinedWireHits.size() <= std::max(track1.size(), track2.size())
      or combinedWireHits.size() < 15) {
    return NAN;
  }
 
  return commonTrajectory2D.getPValue();
}

doTracksMerging()

void doTracksMerging ( std::vector< CDCTrack > &  axialTracks, const std::vector< const CDCWireHit * > &  allAxialWireHits  )

private

The track finding often finds two curling tracks, originating from the same particle.

This function merges them.

Definition at line 68 of file AxialTrackMerger.cc.

{
  // Search for best matches - cannot use range for here :(.
  for (auto itTrack = axialTracks.begin(); itTrack !=  axialTracks.end(); ++itTrack) {
    CDCTrack& track = *itTrack;
    auto followingTracks = asRange(std::next(itTrack), axialTracks.end());
 
    WithWeight<MayBePtr<CDCTrack> > bestTrack = calculateBestTrackToMerge(track, followingTracks);
    double fitProb = bestTrack.getWeight();
 
    if (bestTrack != nullptr and fitProb > m_param_minFitProb) {
      mergeTracks(track, *bestTrack, allAxialWireHits);
    }
  }
 
  AxialTrackUtil::deleteShortTracks(axialTracks);
}

endRun()

void endRun ( )

overridevirtualinherited

Receive and dispatch signal for the end of the run.

Reimplemented from ProcessingSignalListener.

Definition at line 39 of file CompositeProcessingSignalListener.cc.

{
  for (ProcessingSignalListener* psl : reversedRange(m_subordinaryProcessingSignalListeners)) {
    psl->endRun();
  }
  Super::endRun();
}

exposeParameters()

void exposeParameters ( ModuleParamList *  moduleParamList, const std::string &  prefix  )

finalvirtual

Expose the parameters to a module.

Reimplemented from Findlet< AIOTypes >.

Definition at line 32 of file AxialTrackMerger.cc.

{
  moduleParamList->addParameter(prefixed(prefix, "minFitProb"),
                                m_param_minFitProb,
                                "Minimal fit probability of the common fit "
                                "of two tracks to be eligible for merging",
                                m_param_minFitProb);
}

getDescription()

std::string getDescription ( )

finalvirtual

Short description of the findlet.

Reimplemented from Findlet< AIOTypes >.

Definition at line 27 of file AxialTrackMerger.cc.

{
  return "Merges axial tracks found in the legendre search";
}

getNProcessingSignalListener()

int getNProcessingSignalListener ( )

protectedinherited

Get the number of currently registered listeners.

Definition at line 60 of file CompositeProcessingSignalListener.cc.

{
  return m_subordinaryProcessingSignalListeners.size();
}

initialize()

void initialize ( )

overridevirtualinherited

Receive and dispatch signal before the start of the event processing.

Reimplemented from ProcessingSignalListener.

Reimplemented in UnionVarSet< AObject >, UnionVarSet< Object >, VariadicUnionVarSet< AVarSets >, ResultStorer< Belle2::CKFToPXDResult >, ResultStorer< Belle2::CKFToSVDResult >, BaseEventTimeExtractor< RecoTrack * >, BaseEventTimeExtractor< TrackFindingCDC::CDCWireHit & >, StereoHitTrackQuadTreeMatcher< Belle2::TrackFindingCDC::HyperHough >, StereoHitTrackQuadTreeMatcher< Belle2::TrackFindingCDC::QuadraticLegendre >, StereoHitTrackQuadTreeMatcher< Belle2::TrackFindingCDC::Z0TanLambdaLegendre >, OnVarSet< Filter< ATruthVarSet::Object > >, OnVarSet< Filter< AVarSet::Object > >, OnVarSet< BaseFacetFilter >, OnVarSet< BaseFacetRelationFilter >, OnVarSet< BaseAxialSegmentPairFilter >, OnVarSet< BaseSegmentRelationFilter >, OnVarSet< BaseTrackRelationFilter >, OnVarSet< BaseSegmentPairRelationFilter >, MCSymmetric< BaseAxialSegmentPairFilter >, MCSymmetric< BaseFacetFilter >, MCSymmetric< BaseFacetRelationFilter >, MCSymmetric< BaseSegmentPairFilter >, MCSymmetric< BaseSegmentPairRelationFilter >, MCSymmetric< BaseSegmentRelationFilter >, MCSymmetric< BaseSegmentTripleFilter >, MCSymmetric< BaseSegmentTripleRelationFilter >, MCSymmetric< BaseTrackRelationFilter >, StoreArrayLoader< const Belle2::SpacePoint >, StoreArrayLoader< DataStoreInputTypeRefType >, StoreVectorSwapper< Belle2::TrackFindingCDC::CDCFacet >, StoreVectorSwapper< Belle2::TrackFindingCDC::CDCWireHit, true >, StoreVectorSwapper< Belle2::TrackFindingCDC::CDCSegment2D >, StoreVectorSwapper< Belle2::TrackFindingCDC::CDCTrack >, StoreVectorSwapper< Belle2::TrackFindingCDC::CDCSegmentPair >, StoreVectorSwapper< Belle2::TrackFindingCDC::CDCSegmentTriple >, RelationVarSet< ABaseVarSet >, QualityIndicatorFilter, TwoHitVirtualIPQIFilter, MultiHoughSpaceFastInterceptFinder, RawTrackCandCleaner< AHit >, RawTrackCandCleaner< Belle2::vxdHoughTracking::VXDHoughState >, RecoTrackStorer, ROIFinder, SingleHoughSpaceFastInterceptFinder, SpacePointLoaderAndPreparer, TrackCandidateOverlapResolver, and TrackCandidateResultRefiner.

Definition at line 15 of file CompositeProcessingSignalListener.cc.

{
  Super::initialize();
  for (ProcessingSignalListener* psl : m_subordinaryProcessingSignalListeners) {
    psl->initialize();
  }
}

mergeTracks()

void mergeTracks ( CDCTrack &  track1, CDCTrack &  track2, const std::vector< const CDCWireHit * > &  allAxialWireHits  )

staticprivate

Function to merge two track candidates.

The hits of track2 are deleted and transfered to track1 and the track1 is resorted. The method also applys some postprocessing and splits the track1 in case it appears to contain two back-to-back arms,

Definition at line 192 of file AxialTrackMerger.cc.

{
  if (&track1 == &track2) return;
 
  CDCTrajectory2D trajectory2D = track1.getStartTrajectory3D().getTrajectory2D();
  for (const CDCRecoHit3D& orgRecoHit3D : track2) {
    CDCRecoHit3D recoHit3D = CDCRecoHit3D::reconstruct(orgRecoHit3D.getRLWireHit(), trajectory2D);
    track1.push_back(std::move(recoHit3D));
  }
  track2.clear();
 
  AxialTrackUtil::normalizeTrack(track1);
 
  track2 = CDCTrack(AxialTrackUtil::splitBack2BackTrack(track1));
 
  AxialTrackUtil::normalizeTrack(track1);
 
  for (CDCRecoHit3D& recoHit3D : track2) {
    recoHit3D.setRecoPos3D({recoHit3D.getRefPos2D(), 0});
    recoHit3D.setRLInfo(ERightLeft::c_Unknown);
  }
 
  AxialTrackUtil::normalizeTrack(track2);
  bool success = AxialTrackUtil::postprocessTrack(track2, allAxialWireHits);
  if (not success) {
    for (const CDCRecoHit3D& recoHit3D : track2) {
      recoHit3D.getWireHit()->setTakenFlag(false);
    }
    track2.clear();
  }
}

removeStrangeHits()

void removeStrangeHits ( double  factor, std::vector< const CDCWireHit * > &  wireHits, CDCTrajectory2D &  trajectory  )

staticprivate

Remove all hits that are further than factor * driftlength away from the trajectory.

Parameters

factor	gives a number how far the hit is allowed to be.
wireHits	the wirehits that should be considered
trajectory	the reference trajectory

Definition at line 179 of file AxialTrackMerger.cc.

{
  auto farFromTrajectory = [&trajectory2D, &factor](const CDCWireHit * wireHit) {
    Vector2D pos2D = wireHit->getRefPos2D();
    double driftLength = wireHit->getRefDriftLength();
    double dist = std::fabs(trajectory2D.getDist2D(pos2D)) - driftLength;
    return std::fabs(dist) > driftLength * factor;
  };
  erase_remove_if(wireHits, farFromTrajectory);
}

terminate()

void terminate ( )

overridevirtualinherited

Receive and dispatch Signal for termination of the event processing.

Reimplemented from ProcessingSignalListener.

Reimplemented in StereoHitTrackQuadTreeMatcher< Belle2::TrackFindingCDC::HyperHough >, StereoHitTrackQuadTreeMatcher< Belle2::TrackFindingCDC::QuadraticLegendre >, and StereoHitTrackQuadTreeMatcher< Belle2::TrackFindingCDC::Z0TanLambdaLegendre >.

Definition at line 47 of file CompositeProcessingSignalListener.cc.

{
  for (ProcessingSignalListener* psl : reversedRange(m_subordinaryProcessingSignalListeners)) {
    psl->terminate();
  }
  Super::terminate();
}

Member Data Documentation

m_initialized

bool m_initialized = false

privateinherited

Flag to keep track whether initialization happend before.

Definition at line 52 of file ProcessingSignalListener.h.

m_initializedAs

std::string m_initializedAs

privateinherited

Name of the type during initialisation.

Definition at line 58 of file ProcessingSignalListener.h.

m_param_minFitProb

double m_param_minFitProb = 0.85

private

Parameter : Minimal fit probability of the common fit of two tracks to be eligible for merging.

Definition at line 95 of file AxialTrackMerger.h.

m_subordinaryProcessingSignalListeners

std::vector<ProcessingSignalListener*> m_subordinaryProcessingSignalListeners

privateinherited

References to subordinary signal processing listener contained in this findlet.

Definition at line 52 of file CompositeProcessingSignalListener.h.

m_terminated

bool m_terminated = false

privateinherited

Flag to keep track whether termination happend before.

Definition at line 55 of file ProcessingSignalListener.h.

---

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

• tracking/trackFindingCDC/findlets/minimal/include/AxialTrackMerger.h
• tracking/trackFindingCDC/findlets/minimal/src/AxialTrackMerger.cc