#include <ME0SegmentAlgorithm.h>

Inheritance diagram for ME0SegmentAlgorithm:

Public Types
typedef std::vector< const ME0RecHit * >	EnsembleHitContainer
	Typedefs. More...

typedef std::vector < EnsembleHitContainer >	ProtoSegments

Public Types inherited from ME0SegmentAlgorithmBase
typedef std::pair< const ME0Chamber , std::map < uint32_t, const ME0EtaPartition > >	ME0Ensemble

Public Member Functions
	ME0SegmentAlgorithm (const edm::ParameterSet &ps)
	Constructor. More...

std::vector< ME0Segment >	run (const ME0Ensemble &ensemble, const EnsembleHitContainer &rechits)

virtual	~ME0SegmentAlgorithm ()
	Destructor. More...

Public Member Functions inherited from ME0SegmentAlgorithmBase
	ME0SegmentAlgorithmBase (const edm::ParameterSet &)
	Constructor. More...

virtual std::vector< ME0Segment >	run (const ME0Ensemble &ensemble, const std::vector< const ME0RecHit * > &rechits)=0

virtual	~ME0SegmentAlgorithmBase ()
	Destructor. More...

Private Member Functions
void	buildSegments (const ME0Ensemble &ensemble, const EnsembleHitContainer &rechits, std::vector< ME0Segment > &me0segs)

ProtoSegments	chainHits (const ME0Ensemble &ensemble, const EnsembleHitContainer &rechits)

ProtoSegments	clusterHits (const EnsembleHitContainer &rechits)
	Utility functions. More...

bool	isGoodToMerge (const ME0Ensemble &ensemble, const EnsembleHitContainer &newChain, const EnsembleHitContainer &oldChain)

Private Attributes
bool	debug

double	dEtaChainBoxMax

double	dPhiChainBoxMax

double	dTimeChainBoxMax

double	dXclusBoxMax

double	dYclusBoxMax

int	maxRecHitsInCluster

unsigned int	minHitsPerSegment

const std::string	myName

bool	preClustering

bool	preClustering_useChaining

EnsembleHitContainer	proto_segment

std::unique_ptr< MuonSegFit >	sfit_

Static Private Attributes
static float	running_max =std::numeric_limits<float>::max()

Detailed Description

This algorithm is very basic no attemp to deal with ambiguities , noise etc. The ME0 track segments is built out of the rechit's in a the 6 ME0 Layer denoted as the ME0 Ensabmle .

Authors: Marcello Maggi

Definition at line 24 of file ME0SegmentAlgorithm.h.

Member Typedef Documentation

typedef std::vector<const ME0RecHit*> ME0SegmentAlgorithm::EnsembleHitContainer

Typedefs.

Definition at line 30 of file ME0SegmentAlgorithm.h.

typedef std::vector<EnsembleHitContainer> ME0SegmentAlgorithm::ProtoSegments

Definition at line 31 of file ME0SegmentAlgorithm.h.

Constructor & Destructor Documentation

ME0SegmentAlgorithm::ME0SegmentAlgorithm ( const edm::ParameterSet & ps )

explicit

Constructor.

Definition at line 25 of file ME0SegmentAlgorithm.cc.

References debug, dEtaChainBoxMax, dPhiChainBoxMax, dTimeChainBoxMax, dXclusBoxMax, dYclusBoxMax, edm::ParameterSet::getParameter(), edm::ParameterSet::getUntrackedParameter(), maxRecHitsInCluster, minHitsPerSegment, preClustering, and preClustering_useChaining.

                                                                   : ME0SegmentAlgorithmBase(ps), myName("ME0SegmentAlgorithm")
 {
   debug                     = ps.getUntrackedParameter<bool>("ME0Debug");
   minHitsPerSegment         = ps.getParameter<unsigned int>("minHitsPerSegment");
   preClustering             = ps.getParameter<bool>("preClustering");
   dXclusBoxMax              = ps.getParameter<double>("dXclusBoxMax");
   dYclusBoxMax              = ps.getParameter<double>("dYclusBoxMax");
   preClustering_useChaining = ps.getParameter<bool>("preClusteringUseChaining");
   dPhiChainBoxMax           = ps.getParameter<double>("dPhiChainBoxMax");
   dEtaChainBoxMax           = ps.getParameter<double>("dEtaChainBoxMax");
   dTimeChainBoxMax          = ps.getParameter<double>("dTimeChainBoxMax");
   maxRecHitsInCluster       = ps.getParameter<int>("maxRecHitsInCluster");
 
   edm::LogVerbatim("ME0SegmentAlgorithm") << "[ME0SegmentAlgorithm::ctor] Parameters to build segments :: "
                    << "preClustering = "<<preClustering<<" preClustering_useChaining = "<<preClustering_useChaining
                    <<" dPhiChainBoxMax = "<<dPhiChainBoxMax<<" dEtaChainBoxMax = "<<dEtaChainBoxMax<<" dTimeChainBoxMax = "<<dTimeChainBoxMax
                    <<" minHitsPerSegment = "<<minHitsPerSegment<<" maxRecHitsInCluster = "<<maxRecHitsInCluster;
 }

ME0SegmentAlgorithm::~ME0SegmentAlgorithm ( )

virtual

Destructor.

Definition at line 47 of file ME0SegmentAlgorithm.cc.

47 {

48 }

Member Function Documentation

void ME0SegmentAlgorithm::buildSegments	(	const ME0Ensemble &	ensemble,
		const EnsembleHitContainer &	rechits,
		std::vector< ME0Segment > &	me0segs
	)

private

Definition at line 289 of file ME0SegmentAlgorithm.cc.

References ME0RecHit::clone(), runTauDisplay::gp, minHitsPerSegment, funct::pow(), proto_segment, ME0RecHit::setPosition(), sfit_, mathSSE::sqrt(), tmp, GeomDet::toGlobal(), and GeomDet::toLocal().

Referenced by run().

                                                                                                                                         {
   if (rechits.size() < minHitsPerSegment) return;
   
 #ifdef EDM_ML_DEBUG // have lines below only compiled when in debug mode 
   edm::LogVerbatim("ME0SegmentAlgorithm") << "[ME0SegmentAlgorithm::buildSegments] will now try to fit a ME0Segment from collection of "<<rechits.size()<<" ME0 RecHits";
   for (auto rh=rechits.begin(); rh!=rechits.end(); ++rh){
     auto me0id = (*rh)->me0Id();
     auto rhLP = (*rh)->localPosition();
     edm::LogVerbatim("ME0SegmentAlgorithm") << "[RecHit :: Loc x = "<<std::showpos<<std::setw(9)<<rhLP.x()<<" Loc y = "<<std::showpos<<std::setw(9)<<rhLP.y()<<" Time = "<<std::showpos<<(*rh)->tof()<<" -- "<<me0id.rawId()<<" = "<<me0id<<" ]";
   }
 #endif
 
   MuonSegFit::MuonRecHitContainer muonRecHits;
   proto_segment.clear();
   
   // select hits from the ensemble and sort it 
   const ME0Chamber * chamber   = ensemble.first;
   for (auto rh=rechits.begin(); rh!=rechits.end();rh++){
     proto_segment.push_back(*rh);
     // for segFit - using local point in chamber frame
     const ME0EtaPartition * thePartition   = (ensemble.second.find((*rh)->me0Id()))->second;
     GlobalPoint gp = thePartition->toGlobal((*rh)->localPosition());
     const LocalPoint lp = chamber->toLocal(gp);    
     ME0RecHit *newRH = (*rh)->clone();
     newRH->setPosition(lp);
 
     MuonSegFit::MuonRecHitPtr trkRecHit(newRH);
     muonRecHits.push_back(trkRecHit);
   }
 
   // The actual fit on all hits of the vector of the selected Tracking RecHits:
   sfit_ = std::make_unique<MuonSegFit>(muonRecHits);
   bool goodfit = sfit_->fit();
   edm::LogVerbatim("ME0SegmentAlgorithm") << "[ME0SegmentAlgorithm::buildSegments] ME0Segment fit done";
 
   // quit function if fit was not OK  
   if(!goodfit){
     for (auto rh:muonRecHits) rh.reset();
     return;
   }
   
   // obtain all information necessary to make the segment:
   LocalPoint protoIntercept      = sfit_->intercept();
   LocalVector protoDirection     = sfit_->localdir();
   AlgebraicSymMatrix protoErrors = sfit_->covarianceMatrix(); 
   double protoChi2               = sfit_->chi2();
   // Calculate the central value and uncertainty of the segment time
   float averageTime=0.;
   for (auto rh=rechits.begin(); rh!=rechits.end(); ++rh){
     averageTime += (*rh)->tof();                                          
   }
   if(rechits.size() != 0) averageTime=averageTime/(rechits.size());
   float timeUncrt=0.;
   for (auto rh=rechits.begin(); rh!=rechits.end(); ++rh){
     timeUncrt += pow((*rh)->tof()-averageTime,2);
   }
   if(rechits.size() > 1) timeUncrt=timeUncrt/(rechits.size()-1);
   timeUncrt = sqrt(timeUncrt);
 
   // save all information inside GEMCSCSegment
   edm::LogVerbatim("ME0SegmentAlgorithm") << "[ME0SegmentAlgorithm::buildSegments] will now try to make ME0Segment from collection of "<<rechits.size()<<" ME0 RecHits";
   ME0Segment tmp(proto_segment, protoIntercept, protoDirection, protoErrors, protoChi2, averageTime, timeUncrt);
 
   edm::LogVerbatim("ME0SegmentAlgorithm") << "[ME0SegmentAlgorithm::buildSegments] ME0Segment made";
   edm::LogVerbatim("ME0SegmentAlgorithm") << "[ME0SegmentAlgorithm::buildSegments] "<<tmp;
   
   for (auto rh:muonRecHits) rh.reset();
   me0segs.push_back(tmp);
   return;
 }

ME0SegmentAlgorithm::ProtoSegments ME0SegmentAlgorithm::chainHits	(	const ME0Ensemble &	ensemble,
		const EnsembleHitContainer &	rechits
	)

private

Definition at line 196 of file ME0SegmentAlgorithm.cc.

References funct::abs(), begin, dTimeChainBoxMax, end, i, and isGoodToMerge().

Referenced by run().

                                                                                                {
 
   ProtoSegments rechits_chains; 
   ProtoSegments seeds;
   seeds.reserve(rechits.size());
   std::vector<bool> usedCluster(rechits.size(),false);
   
   // split rechits into subvectors and return vector of vectors:
   // Loop over rechits
   // Create one seed per hit
   for ( unsigned int i=0; i<rechits.size(); ++i){
     if(std::abs(rechits[i]->tof()) > dTimeChainBoxMax) continue;
     seeds.push_back(EnsembleHitContainer(1,rechits[i]));
   }
   
   // merge chains that are too close ("touch" each other)
   for(size_t NNN = 0; NNN < seeds.size(); ++NNN) {
     for(size_t MMM = NNN+1; MMM < seeds.size(); ++MMM) {
       if(usedCluster[MMM] || usedCluster[NNN]){
         continue;
       }
       // all is in the way we define "good";
       // try not to "cluster" the hits but to "chain" them;
       // it does the clustering but also does a better job
       // for inclined tracks (not clustering them together;
       // crossed tracks would be still clustered together) 
       // 22.12.09: In fact it is not much more different 
       // than the "clustering", we just introduce another
       // variable in the game - Z. And it makes sense 
       // to re-introduce Y (or actually wire group mumber)
       // in a similar way as for the strip number - see
       // the code below.
       bool goodToMerge  = isGoodToMerge(ensemble, seeds[NNN], seeds[MMM]);
       if(goodToMerge){
         // merge chains!
         // merge by adding seed NNN to seed MMM and erasing seed NNN
 
         // add seed NNN to MMM (lower to larger number)
         seeds[MMM].insert(seeds[MMM].end(),seeds[NNN].begin(),seeds[NNN].end());
 
         // mark seed NNN as used
         usedCluster[NNN] = true;
         // we have merged a seed (NNN) to the highter seed (MMM) - need to contimue to
         // next seed (NNN+1)
         break;
       }
 
     }
   }
 
   // hand over the final seeds to the output
   // would be more elegant if we could do the above step with
   // erasing the merged ones, rather than the
 
   for(size_t NNN = 0; NNN < seeds.size(); ++NNN) {
     if(usedCluster[NNN]) continue; //skip seeds that have been marked as used up in merging
     rechits_chains.push_back(seeds[NNN]);
   }
 
   //***************************************************************
 
   return rechits_chains;
 }

ME0SegmentAlgorithm::ProtoSegments ME0SegmentAlgorithm::clusterHits ( const EnsembleHitContainer & rechits )

private

Utility functions.

Definition at line 99 of file ME0SegmentAlgorithm.cc.

References begin, dXclusBoxMax, dYclusBoxMax, end, i, LogDebug, running_max, findQualityFiles::size, x, and y.

Referenced by run().

                                                                     {
 
   ProtoSegments rechits_clusters; // this is a collection of groups of rechits
 
   float dXclus_box = 0.0;
   float dYclus_box = 0.0;
 
   ProtoSegments seeds; seeds.reserve(rechits.size());
 
   std::vector<float> running_meanX; running_meanX.reserve(rechits.size());
   std::vector<float> running_meanY; running_meanY.reserve(rechits.size());
 
   std::vector<float> seed_minX; seed_minX.reserve(rechits.size());
   std::vector<float> seed_maxX; seed_maxX.reserve(rechits.size());
   std::vector<float> seed_minY; seed_minY.reserve(rechits.size());
   std::vector<float> seed_maxY; seed_maxY.reserve(rechits.size());
 
   // split rechits into subvectors and return vector of vectors:
   // Loop over rechits 
   // Create one seed per hit
   for(unsigned int i = 0; i < rechits.size(); ++i) {
     seeds.push_back(EnsembleHitContainer(1,rechits[i]));
 
     // First added hit in seed defines the mean to which the next hit is compared
     // for this seed.
 
     running_meanX.push_back( rechits[i]->localPosition().x() );
     running_meanY.push_back( rechits[i]->localPosition().y() );
     
     // set min/max X and Y for box containing the hits in the precluster:
     seed_minX.push_back( rechits[i]->localPosition().x() );
     seed_maxX.push_back( rechits[i]->localPosition().x() );
     seed_minY.push_back( rechits[i]->localPosition().y() );
     seed_maxY.push_back( rechits[i]->localPosition().y() );
   }
     
   // merge clusters that are too close
   // measure distance between final "running mean"
   for(size_t NNN = 0; NNN < seeds.size(); ++NNN) {
     for(size_t MMM = NNN+1; MMM < seeds.size(); ++MMM) {
       if(running_meanX[MMM] == running_max || running_meanX[NNN] == running_max ) {
     LogDebug("ME0SegmentAlgorithm") << "[ME0SegmentAlgorithm::clusterHits]: ALARM! Skipping used seeds, this should not happen - inform developers!";
     continue; //skip seeds that have been used 
       }
       
       // calculate cut criteria for simple running mean distance cut:
       //dXclus = fabs(running_meanX[NNN] - running_meanX[MMM]);
       //dYclus = fabs(running_meanY[NNN] - running_meanY[MMM]);
       // calculate minmal distance between precluster boxes containing the hits:
       if ( running_meanX[NNN] > running_meanX[MMM] ) dXclus_box = seed_minX[NNN] - seed_maxX[MMM];
       else                                           dXclus_box = seed_minX[MMM] - seed_maxX[NNN];
       if ( running_meanY[NNN] > running_meanY[MMM] ) dYclus_box = seed_minY[NNN] - seed_maxY[MMM];
       else                                           dYclus_box = seed_minY[MMM] - seed_maxY[NNN];
       
       
       if( dXclus_box < dXclusBoxMax && dYclus_box < dYclusBoxMax ) {
     // merge clusters!
     // merge by adding seed NNN to seed MMM and erasing seed NNN
         
     // calculate running mean for the merged seed:
     if(seeds[NNN].size()+seeds[MMM].size() != 0) {
       running_meanX[MMM] = (running_meanX[NNN]*seeds[NNN].size() + running_meanX[MMM]*seeds[MMM].size()) / (seeds[NNN].size()+seeds[MMM].size());
       running_meanY[MMM] = (running_meanY[NNN]*seeds[NNN].size() + running_meanY[MMM]*seeds[MMM].size()) / (seeds[NNN].size()+seeds[MMM].size());
     }
 
     // update min/max X and Y for box containing the hits in the merged cluster:
     if ( seed_minX[NNN] <  seed_minX[MMM] ) seed_minX[MMM] = seed_minX[NNN];
     if ( seed_maxX[NNN] >  seed_maxX[MMM] ) seed_maxX[MMM] = seed_maxX[NNN];
     if ( seed_minY[NNN] <  seed_minY[MMM] ) seed_minY[MMM] = seed_minY[NNN];
     if ( seed_maxY[NNN] >  seed_maxY[MMM] ) seed_maxY[MMM] = seed_maxY[NNN];
         
     // add seed NNN to MMM (lower to larger number)
     seeds[MMM].insert(seeds[MMM].end(),seeds[NNN].begin(),seeds[NNN].end());
         
     // mark seed NNN as used (at the moment just set running mean to 999999.)
     running_meanX[NNN] = running_max;
     running_meanY[NNN] = running_max;
     // we have merged a seed (NNN) to the highter seed (MMM) - need to contimue to 
     // next seed (NNN+1)
     break;
       }
     }
   }
 
   // hand over the final seeds to the output
   // would be more elegant if we could do the above step with 
   // erasing the merged ones, rather than the 
   for(size_t NNN = 0; NNN < seeds.size(); ++NNN) {
     if(running_meanX[NNN] == running_max) continue; //skip seeds that have been marked as used up in merging
     rechits_clusters.push_back(seeds[NNN]);
   }
 
   return rechits_clusters; 
 }

bool ME0SegmentAlgorithm::isGoodToMerge	(	const ME0Ensemble &	ensemble,
		const EnsembleHitContainer &	newChain,
		const EnsembleHitContainer &	oldChain
	)

private

Definition at line 260 of file ME0SegmentAlgorithm.cc.

References funct::abs(), reco::deltaPhi(), dEtaChainBoxMax, dPhiChainBoxMax, dTimeChainBoxMax, PV3DBase< T, PVType, FrameType >::eta(), and PV3DBase< T, PVType, FrameType >::phi().

Referenced by chainHits().

                                                                                                                                                {
   for(size_t iRH_new = 0;iRH_new<newChain.size();++iRH_new){
     GlobalPoint pos_new = ensemble.first->toGlobal(newChain[iRH_new]->localPosition());
           
     for(size_t iRH_old = 0;iRH_old<oldChain.size();++iRH_old){
       GlobalPoint pos_old = ensemble.first->toGlobal(oldChain[iRH_old]->localPosition());
       // to be chained, two hits need to be in neighbouring layers...
       // or better allow few missing layers (upto 3 to avoid inefficiencies);
       // however we'll not make an angle correction because it
       // worsen the situation in some of the "regular" cases 
       // (not making the correction means that the conditions for
       // forming a cluster are different if we have missing layers -
       // this could affect events at the boundaries ) 
 
       // to be chained, two hits need also to be "close" in phi and eta
       if (std::abs(reco::deltaPhi( float(pos_new.phi()), float(pos_old.phi()) )) >= dPhiChainBoxMax) continue;
       if (std::abs(pos_new.eta()-pos_old.eta()) >= dEtaChainBoxMax) continue;
       // and the difference in layer index should be < (nlayers-1)
       if (std::abs(newChain[iRH_new]->me0Id().layer() - oldChain[iRH_old]->me0Id().layer()) >= (ensemble.first->id().nlayers()-1)) continue;
       // and they should have a time difference compatible with the hypothesis 
       // that the rechits originate from the same particle, but were detected in different layers
       if (std::abs(newChain[iRH_new]->tof() - oldChain[iRH_old]->tof()) >= dTimeChainBoxMax) continue;
 
       return true;
     }
   }
   return false;
 }

std::vector< ME0Segment > ME0SegmentAlgorithm::run	(	const ME0Ensemble &	ensemble,
		const EnsembleHitContainer &	rechits
	)

Build segments for all desired groups of hits

Definition at line 51 of file ME0SegmentAlgorithm.cc.

References buildSegments(), chainHits(), clusterHits(), preClustering, and preClustering_useChaining.

                                                                                                                {
 
   #ifdef EDM_ML_DEBUG // have lines below only compiled when in debug mode
   ME0DetId chId((ensemble.first)->id());  
   edm::LogVerbatim("ME0SegAlgoMM") << "[ME0SegmentAlgorithm::run] build segments in chamber " << chId << " which contains "<<rechits.size()<<" rechits";
   for (auto rh=rechits.begin(); rh!=rechits.end(); ++rh){
     auto me0id = (*rh)->me0Id();
     auto rhLP = (*rh)->localPosition();
     edm::LogVerbatim("ME0SegmentAlgorithm") << "[RecHit :: Loc x = "<<std::showpos<<std::setw(9)<<rhLP.x()<<" Loc y = "<<std::showpos<<std::setw(9)<<rhLP.y()<<" Time = "<<std::showpos<<(*rh)->tof()<<" -- "<<me0id.rawId()<<" = "<<me0id<<" ]";
   }
   #endif
 
   // pre-cluster rechits and loop over all sub clusters separately
   std::vector<ME0Segment>          segments_temp;
   std::vector<ME0Segment>          segments;
   ProtoSegments rechits_clusters; // this is a collection of groups of rechits
   
   if(preClustering) {
     // run a pre-clusterer on the given rechits to split obviously separated segment seeds:
     if(preClustering_useChaining){
       // it uses X,Y,Z information; there are no configurable parameters used;
       // the X, Y, Z "cuts" are just (much) wider than reasonable high pt segments
       rechits_clusters = this->chainHits(ensemble, rechits );
     }
     else{
       // it uses X,Y information + configurable parameters
       rechits_clusters = this->clusterHits(rechits );
     }
     // loop over the found clusters:
     for(auto sub_rechits = rechits_clusters.begin(); sub_rechits !=  rechits_clusters.end(); ++sub_rechits ) {
       // clear the buffer for the subset of segments:
       segments_temp.clear();
       // build the subset of segments:
       this->buildSegments(ensemble, (*sub_rechits), segments_temp );
       // add the found subset of segments to the collection of all segments in this chamber:
       segments.insert( segments.end(), segments_temp.begin(), segments_temp.end() );
     }
     return segments;
   }
   else {
     this->buildSegments(ensemble, rechits, segments);
     return segments;
   }
 }