Produces reco::GenParticle from SimTracks. More...

Inheritance diagram for pat::GenPlusSimParticleProducer:

Classes
struct	LessById

Public Member Functions
	GenPlusSimParticleProducer (const edm::ParameterSet &)

	~GenPlusSimParticleProducer ()

Public Member Functions inherited from edm::EDProducer
	EDProducer ()

virtual	~EDProducer ()

Public Member Functions inherited from edm::ProducerBase
	ProducerBase ()

void	registerProducts (ProducerBase , ProductRegistry , ModuleDescription const &)

boost::function< void(const BranchDescription &)>	registrationCallback () const
	used by the fwk to register list of products More...

virtual	~ProducerBase ()

Private Types
typedef StringCutObjectSelector < reco::GenParticle >	StrFilter

Private Member Functions
void	addGenParticle (const SimTrack &stMom, const SimTrack &stDau, unsigned int momidx, const edm::SimTrackContainer &simtks, const edm::SimVertexContainer &simvtxs, reco::GenParticleCollection &mergedGens, const reco::GenParticleRefProd ref, std::vector< int > &genBarcodes, bool &barcodesAreSorted) const
	Try to link the GEANT particle to the generator particle it came from. More...

virtual void	endJob ()

virtual void	produce (edm::Event &, const edm::EventSetup &)

Private Attributes
std::auto_ptr< StrFilter >	filter_

bool	firstEvent_

edm::InputTag	genParticles_
	Collection of GenParticles I need to make refs to. It must also have its associated vector<int> of barcodes, aligned with them. More...

std::set< int >	pdgIds_

std::vector< PdtEntry >	pdts_

int	setStatus_

edm::InputTag	src_

Additional Inherited Members
Public Types inherited from edm::EDProducer
typedef EDProducer	ModuleType

typedef WorkerT< EDProducer >	WorkerType

Public Types inherited from edm::ProducerBase
typedef ProductRegistryHelper::TypeLabelList	TypeLabelList

Static Public Member Functions inherited from edm::EDProducer
static const std::string &	baseType ()

static void	fillDescriptions (ConfigurationDescriptions &descriptions)

Protected Member Functions inherited from edm::EDProducer
CurrentProcessingContext const *	currentContext () const

Protected Member Functions inherited from edm::ProducerBase
template<class TProducer , class TMethod >
void	callWhenNewProductsRegistered (TProducer *iProd, TMethod iMethod)

Detailed Description

Produces reco::GenParticle from SimTracks.

The GenPlusSimParticleProducer produces GenParticles from SimTracks, so they can be used for MC matching. A copy of the original genParticle list is made and the genParticles created from the GEANT/FAMOS particles are added to the list including all ancestors and correct mother/daughter references

Sample useage in cfg.py file: process.genParticlePlusGEANT = cms.EDProducer("GenPlusSimParticleProducer", src = cms.InputTag("g4SimHits"), # use "famosSimHits" for FAMOS setStatus = cms.int32(8), # set status = 8 for GEANT GPs particleTypes = cms.vstring("pi+"), # also picks pi- (optional) filter = cms.vstring("pt > 0.0"), # just for testing genParticles = cms.InputTag("genParticles") # original genParticle list )

Author: Jordan Tucker (original module), Keith Ulmer (generalization)

Definition at line 39 of file GenPlusSimParticleProducer.cc.

Member Typedef Documentation

typedef StringCutObjectSelector<reco::GenParticle> pat::GenPlusSimParticleProducer::StrFilter

private

Definition at line 54 of file GenPlusSimParticleProducer.cc.

Constructor & Destructor Documentation

GenPlusSimParticleProducer::GenPlusSimParticleProducer ( const edm::ParameterSet & cfg )

explicit

Definition at line 97 of file GenPlusSimParticleProducer.cc.

References edm::ParameterSet::exists(), edm::ParameterSet::existsAs(), align_tpl::filter, filter_, edm::ParameterSet::getParameter(), and pdts_.

                                                                               :
   firstEvent_(true),
   src_(cfg.getParameter<InputTag>("src")),            // source sim tracks & vertices
   setStatus_(cfg.getParameter<int32_t>("setStatus")), // set status of GenParticle to this code
   genParticles_(cfg.getParameter<InputTag>("genParticles")) // get the genParticles to add GEANT particles to
 {
   // Possibly allow a list of particle types
   if (cfg.exists("particleTypes")) {
     pdts_ = cfg.getParameter<vector<PdtEntry> >("particleTypes");
   }
   
   // Possibly allow a string cut
   if (cfg.existsAs<string>("filter")) {
     string filter = cfg.getParameter<string>("filter");
     if (!filter.empty()) {
       filter_ = auto_ptr<StrFilter>(new StrFilter(filter));
     }
   }
   produces<GenParticleCollection>();
   produces<vector<int> >();
 }

pat::GenPlusSimParticleProducer::~GenPlusSimParticleProducer ( )

inline

Definition at line 42 of file GenPlusSimParticleProducer.cc.

42 {}

Member Function Documentation

void GenPlusSimParticleProducer::addGenParticle	(	const SimTrack &	stMom,
		const SimTrack &	stDau,
		unsigned int	momidx,
		const edm::SimTrackContainer &	simtks,
		const edm::SimVertexContainer &	simvtxs,
		reco::GenParticleCollection &	mergedGens,
		const reco::GenParticleRefProd	ref,
		std::vector< int > &	genBarcodes,
		bool &	barcodesAreSorted
	)		const

private

Try to link the GEANT particle to the generator particle it came from.

Arguments: – Specific – gp: GenParticle made from the GEANT particle st: The GEANT simTrack for which we create a genParticle

– GEANT related – simtks: A list of GEANT tracks, sorted by track id simvtxs: The list of GEANT vertices, in their natural order (skimtks have pointers into this vector!)

– GenParticle related – gens : Handle to the GenParticles, to make the ref to genBarcodes : Barcodes for each GenParticle, in a vector aligned to the GenParticleCollection. barcodesAreSorted: true if the barcodes are sorted (which means I can use binary_search on them)

Definition at line 119 of file GenPlusSimParticleProducer.cc.

References reco::CompositeRefCandidateT< D >::addDaughter(), DeDxDiscriminatorTools::charge(), CoreSimTrack::charge(), filter_, EgammaValidation_cff::genp, CoreSimTrack::momentum(), SimVertex::noParent(), SimTrack::noVertex(), p4, SimVertex::parentIndex(), setStatus_, CoreSimTrack::trackId(), CoreSimTrack::type(), and SimTrack::vertIndex().

Referenced by produce().

 {
   // Make the genParticle for stDau and add it to the new collection and update the parent-child relationship
   // Make up a GenParticleCandidate from the GEANT track info.
   int charge = static_cast<int>(stDau.charge());
   Particle::LorentzVector p4 = stDau.momentum();
   Particle::Point vtx; // = (0,0,0) by default
   if (!stDau.noVertex()) vtx = simvertices[stDau.vertIndex()].position();
   GenParticle genp(charge, p4, vtx, stDau.type(), setStatus_, true);
   
   // Maybe apply filter on the particle
   if (filter_.get() != 0) {
     if (!(*filter_)(genp)) return;
   }
   
   reco::GenParticleRef parentRef(ref, momidx);
   genp.addMother(parentRef);
   mergedGens.push_back(genp);
   // get the index for the daughter just added
   unsigned int dauidx = mergedGens.size()-1;
 
   // update add daughter relationship
   reco::GenParticle & cand = mergedGens[ momidx ];
   cand.addDaughter( GenParticleRef( ref, dauidx) );
 
   //look for simtrack daughters of stDau to see if we need to recur further down the chain
   
   for (SimTrackContainer::const_iterator isimtrk = simtracksSorted.begin();
        isimtrk != simtracksSorted.end(); ++isimtrk) {
     if (!isimtrk->noVertex()) {
       // Pick the vertex (isimtrk.vertIndex() is really an index)
       const SimVertex &vtx = simvertices[isimtrk->vertIndex()];
       
       // Check if the vertex has a parent track (otherwise, we're lost)
       if (!vtx.noParent()) {
     
     // Now note that vtx.parentIndex() is NOT an index, it's a track id, so I have to search for it 
     unsigned int idx = vtx.parentIndex();
     SimTrackContainer::const_iterator it = std::lower_bound(simtracksSorted.begin(), simtracksSorted.end(), idx, LessById());
     if ((it != simtracksSorted.end()) && (it->trackId() == idx)) {
       if (it->trackId()==stDau.trackId()) {
         //need the genparticle index of stDau which is dauidx
         addGenParticle(stDau, *isimtrk, dauidx, simtracksSorted, simvertices, mergedGens, ref, genBarcodes, barcodesAreSorted);
       }
     }
       }
     }
   }
 }

virtual void pat::GenPlusSimParticleProducer::endJob ( void )

inlineprivatevirtual

Reimplemented from edm::EDProducer.

Definition at line 46 of file GenPlusSimParticleProducer.cc.

46 {}

void GenPlusSimParticleProducer::produce	(	edm::Event &	event,
		const edm::EventSetup &	iSetup
	)

privatevirtual

Implements edm::EDProducer.

Definition at line 177 of file GenPlusSimParticleProducer.cc.

                                                   {
   if (firstEvent_){
     if (!pdts_.empty()) {
       pdgIds_.clear();
       for (vector<PdtEntry>::iterator itp = pdts_.begin(), edp = pdts_.end(); itp != edp; ++itp) {
         itp->setup(iSetup); // decode string->pdgId and vice-versa                                                                                                      
         pdgIds_.insert(std::abs(itp->pdgId()));
       }
       pdts_.clear();
     }
     firstEvent_ = false;
   }
 
   // Simulated tracks (i.e. GEANT particles).
   Handle<SimTrackContainer> simtracks;
   event.getByLabel(src_, simtracks);
   
   // Need to check that SimTrackContainer is sorted; otherwise, copy and sort :-(
   std::auto_ptr<SimTrackContainer> simtracksTmp;
   const SimTrackContainer * simtracksSorted = &* simtracks;
   if (!__gnu_cxx::is_sorted(simtracks->begin(), simtracks->end(), LessById())) {
     simtracksTmp.reset(new SimTrackContainer(*simtracks));
     std::sort(simtracksTmp->begin(), simtracksTmp->end(), LessById());
     simtracksSorted = &* simtracksTmp;
   }
   
   // Get the associated vertices
   Handle<SimVertexContainer> simvertices;
   event.getByLabel(src_, simvertices);
   
   // Get the GenParticles and barcodes, if needed to set mother and daughter links
   Handle<GenParticleCollection> gens;
   Handle<std::vector<int> > genBarcodes;
   bool barcodesAreSorted = true;
   event.getByLabel(genParticles_, gens);
   event.getByLabel(genParticles_, genBarcodes);
   if (gens->size() != genBarcodes->size()) throw cms::Exception("Corrupt data") << "Barcodes not of the same size as GenParticles!\n";
   
   // make the output collection
   auto_ptr<GenParticleCollection> candsPtr(new GenParticleCollection);
   GenParticleCollection & cands = * candsPtr;
   
   const GenParticleRefProd ref = event.getRefBeforePut<GenParticleCollection>();
   
   // add the original genParticles to the merged output list
   for( size_t i = 0; i < gens->size(); ++ i ) {
     reco::GenParticle cand((*gens)[i]);
     cands.push_back(cand);
   }
   
   // make new barcodes vector and fill it with the original list
   auto_ptr<vector<int> > newGenBarcodes( new vector<int>() );
   for (unsigned int i = 0; i < genBarcodes->size(); ++i) {
     newGenBarcodes->push_back((*genBarcodes)[i]);
   }
   barcodesAreSorted = __gnu_cxx::is_sorted(newGenBarcodes->begin(), newGenBarcodes->end());
   
   for( size_t i = 0; i < cands.size(); ++ i ) {
     reco::GenParticle & cand = cands[ i ];
     size_t nDaus = cand.numberOfDaughters();
     GenParticleRefVector daus = cand.daughterRefVector();
     cand.resetDaughters( ref.id() );
     for ( size_t d = 0; d < nDaus; ++d) {
       cand.addDaughter( GenParticleRef( ref, daus[d].key() ) );
     }
     
     size_t nMoms = cand.numberOfMothers();
     GenParticleRefVector moms = cand.motherRefVector();
     cand.resetMothers( ref.id() );
     for ( size_t m = 0; m < nMoms; ++m) {
       cand.addMother( GenParticleRef( ref, moms[m].key() ) );
     }
   }
   
   for (SimTrackContainer::const_iterator isimtrk = simtracks->begin();
        isimtrk != simtracks->end(); ++isimtrk) {
     
     // Skip PYTHIA tracks.
     if (isimtrk->genpartIndex() != -1) continue; 
     
     // Maybe apply the PdgId filter
     if (!pdgIds_.empty()) { // if we have a filter on pdg ids
       if (pdgIds_.find(std::abs(isimtrk->type())) == pdgIds_.end()) continue;
     }
     
     // find simtrack that has a genParticle match to its parent
     // Look at the production vertex. If there is no vertex, I can do nothing...
     if (!isimtrk->noVertex()) {
       
       // Pick the vertex (isimtrk.vertIndex() is really an index)
       const SimVertex &vtx = (*simvertices)[isimtrk->vertIndex()];
       
       // Check if the vertex has a parent track (otherwise, we're lost)
       if (!vtx.noParent()) {
     
     // Now note that vtx.parentIndex() is NOT an index, it's a track id, so I have to search for it 
     unsigned int idx = vtx.parentIndex();
     SimTrackContainer::const_iterator it = std::lower_bound(simtracksSorted->begin(), simtracksSorted->end(), idx, LessById());
     if ((it != simtracksSorted->end()) && (it->trackId() == idx)) { //it is the parent sim track
       if (it->genpartIndex() != -1) {
         std::vector<int>::const_iterator itIndex;
         if (barcodesAreSorted) {
           itIndex = std::lower_bound(genBarcodes->begin(), genBarcodes->end(), it->genpartIndex());
         } else {
           itIndex = std::find(       genBarcodes->begin(), genBarcodes->end(), it->genpartIndex());
         }
         
         // Check that I found something
         // I need to check '*itIndex == it->genpartIndex()' because lower_bound just finds the right spot for an item in a sorted list, not the item
         if ((itIndex != genBarcodes->end()) && (*itIndex == it->genpartIndex())) {
           // Ok, I'll make the genParticle for st and add it to the new collection updating the map and parent-child relationship
           // pass the mother and daughter sim tracks and the mother genParticle to method to create the daughter genParticle and recur
           unsigned int momidx = itIndex - genBarcodes->begin();
           addGenParticle(*it, *isimtrk, momidx, *simtracksSorted, *simvertices, *candsPtr, ref, *newGenBarcodes, barcodesAreSorted);
         }
       }
     }
       }
     }   
   }
   
   event.put(candsPtr);
   event.put(newGenBarcodes);
 }