TrackFromSeedProducer.cc

Go to the documentation of this file.

// -*- C++ -*-
//
// Package:    FastSimulation/TrackFromSeedProducer
// Class:      TrackFromSeedProducer
//
//
// Original Author:  Lukas Vanelderen
//         Created:  Thu, 28 May 2015 13:27:33 GMT
//
//
 
// system include files
#include <memory>
 
// user include files
#include "FWCore/Framework/interface/Frameworkfwd.h"
#include "FWCore/Framework/interface/ESHandle.h"
#include "FWCore/Framework/interface/global/EDProducer.h"
 
#include "FWCore/Framework/interface/Event.h"
#include "FWCore/Framework/interface/MakerMacros.h"
 
#include "FWCore/ParameterSet/interface/ParameterSet.h"
 
#include "DataFormats/TrackReco/interface/Track.h"
#include "DataFormats/TrackReco/interface/TrackFwd.h"
#include "DataFormats/TrajectorySeed/interface/TrajectorySeed.h"
#include "TrackingTools/TrajectoryState/interface/FreeTrajectoryState.h"
#include "TrackingTools/PatternTools/interface/TSCBLBuilderNoMaterial.h"
#include "TrackingTools/TrajectoryState/interface/PerigeeConversions.h"
#include "TrackingTools/TransientTrackingRecHit/interface/TransientTrackingRecHitBuilder.h"
#include "TrackingTools/Records/interface/TransientRecHitRecord.h"
#include "MagneticField/Records/interface/IdealMagneticFieldRecord.h"
#include "TrackingTools/TrajectoryState/interface/TrajectoryStateTransform.h"
#include "DataFormats/BeamSpot/interface/BeamSpot.h"
 
//
// class declaration
//
 
class TrackFromSeedProducer : public edm::global::EDProducer<> {
public:
  explicit TrackFromSeedProducer(const edm::ParameterSet&);
  ~TrackFromSeedProducer() override;
 
  static void fillDescriptions(edm::ConfigurationDescriptions& descriptions);
 
private:
  void produce(edm::StreamID, edm::Event&, const edm::EventSetup&) const override;
 
  // ----------member data ---------------------------
  edm::EDGetTokenT<edm::View<TrajectorySeed> > seedsToken;
  edm::EDGetTokenT<reco::BeamSpot> beamSpotToken;
  std::string tTRHBuilderName;
};
 
//
// constants, enums and typedefs
//
 
//
// static data member definitions
//
 
//
// constructors and destructor
//
TrackFromSeedProducer::TrackFromSeedProducer(const edm::ParameterSet& iConfig) {
  //register your products
  produces<reco::TrackCollection>();
  produces<TrackingRecHitCollection>();
  produces<reco::TrackExtraCollection>();
 
  // read parametes
  edm::InputTag seedsTag(iConfig.getParameter<edm::InputTag>("src"));
  edm::InputTag beamSpotTag(iConfig.getParameter<edm::InputTag>("beamSpot"));
  tTRHBuilderName = iConfig.getParameter<std::string>("TTRHBuilder");
 
  //consumes
  seedsToken = consumes<edm::View<TrajectorySeed> >(seedsTag);
  beamSpotToken = consumes<reco::BeamSpot>(beamSpotTag);
}
 
TrackFromSeedProducer::~TrackFromSeedProducer() {}
 
// ------------ method called to produce the data  ------------
void TrackFromSeedProducer::produce(edm::StreamID, edm::Event& iEvent, const edm::EventSetup& iSetup) const {
  using namespace edm;
  using namespace reco;
  using namespace std;
 
  // output collection
  unique_ptr<TrackCollection> tracks(new TrackCollection);
  unique_ptr<TrackingRecHitCollection> rechits(new TrackingRecHitCollection);
  unique_ptr<TrackExtraCollection> trackextras(new TrackExtraCollection);
 
  // product references
  TrackExtraRefProd ref_trackextras = iEvent.getRefBeforePut<TrackExtraCollection>();
  TrackingRecHitRefProd ref_rechits = iEvent.getRefBeforePut<TrackingRecHitCollection>();
 
  // input collection
  Handle<edm::View<TrajectorySeed> > hseeds;
  iEvent.getByToken(seedsToken, hseeds);
  const auto& seeds = *hseeds;
 
  // beam spot
  edm::Handle<reco::BeamSpot> beamSpot;
  iEvent.getByToken(beamSpotToken, beamSpot);
 
  // some objects to build to tracks
  TSCBLBuilderNoMaterial tscblBuilder;
 
  edm::ESHandle<TransientTrackingRecHitBuilder> tTRHBuilder;
  iSetup.get<TransientRecHitRecord>().get(tTRHBuilderName, tTRHBuilder);
 
  edm::ESHandle<MagneticField> theMF;
  iSetup.get<IdealMagneticFieldRecord>().get(theMF);
 
  edm::ESHandle<TrackerTopology> httopo;
  iSetup.get<TrackerTopologyRcd>().get(httopo);
  const TrackerTopology& ttopo = *httopo;
 
  // create tracks from seeds
  int nfailed = 0;
  for (size_t iSeed = 0; iSeed < seeds.size(); ++iSeed) {
    auto const& seed = seeds[iSeed];
    // try to create a track
    TransientTrackingRecHit::RecHitPointer lastRecHit = tTRHBuilder->build(&*(seed.recHits().end() - 1));
    TrajectoryStateOnSurface state =
        trajectoryStateTransform::transientState(seed.startingState(), lastRecHit->surface(), theMF.product());
    TrajectoryStateClosestToBeamLine tsAtClosestApproachSeed =
        tscblBuilder(*state.freeState(), *beamSpot);  //as in TrackProducerAlgorithm
    if (tsAtClosestApproachSeed.isValid()) {
      const reco::TrackBase::Point vSeed1(tsAtClosestApproachSeed.trackStateAtPCA().position().x(),
                                          tsAtClosestApproachSeed.trackStateAtPCA().position().y(),
                                          tsAtClosestApproachSeed.trackStateAtPCA().position().z());
      const reco::TrackBase::Vector pSeed(tsAtClosestApproachSeed.trackStateAtPCA().momentum().x(),
                                          tsAtClosestApproachSeed.trackStateAtPCA().momentum().y(),
                                          tsAtClosestApproachSeed.trackStateAtPCA().momentum().z());
      //GlobalPoint vSeed(vSeed1.x()-beamSpot->x0(),vSeed1.y()-beamSpot->y0(),vSeed1.z()-beamSpot->z0());
      PerigeeTrajectoryError seedPerigeeErrors =
          PerigeeConversions::ftsToPerigeeError(tsAtClosestApproachSeed.trackStateAtPCA());
      tracks->emplace_back(0., 0., vSeed1, pSeed, state.charge(), seedPerigeeErrors.covarianceMatrix());
    } else {
      edm::LogVerbatim("SeedValidator") << "TrajectoryStateClosestToBeamLine not valid";
      // use magic values chi2<0, ndof<0, charge=0 to denote a case where the fit has failed
      // If this definition is changed, change also interface/trackFromSeedFitFailed.h
      tracks->emplace_back(
          -1, -1, reco::TrackBase::Point(), reco::TrackBase::Vector(), 0, reco::TrackBase::CovarianceMatrix());
      nfailed++;
    }
 
    tracks->back().appendHits(seed.recHits().begin(), seed.recHits().end(), ttopo);
    // store the hits
    size_t firsthitindex = rechits->size();
    for (auto const& recHit : seed.recHits()) {
      rechits->push_back(recHit);
    }
 
    // create a trackextra, just to store the hit range
    trackextras->push_back(TrackExtra());
    trackextras->back().setHits(ref_rechits, firsthitindex, rechits->size() - firsthitindex);
    trackextras->back().setSeedRef(edm::RefToBase<TrajectorySeed>(hseeds, iSeed));
    // create link between track and trackextra
    tracks->back().setExtra(TrackExtraRef(ref_trackextras, trackextras->size() - 1));
  }
 
  if (nfailed > 0) {
    edm::LogInfo("SeedValidator") << "failed to create tracks from " << nfailed << " out of " << seeds.size()
                                  << " seeds ";
  }
  iEvent.put(std::move(tracks));
  iEvent.put(std::move(rechits));
  iEvent.put(std::move(trackextras));
}
 
// ------------ method fills 'descriptions' with the allowed parameters for the module  ------------
void TrackFromSeedProducer::fillDescriptions(edm::ConfigurationDescriptions& descriptions) {
  //The following says we do not know what parameters are allowed so do no validation
  // Please change this to state exactly what you do use, even if it is no parameters
  edm::ParameterSetDescription desc;
  desc.setUnknown();
  descriptions.addDefault(desc);
}
 
//define this as a plug-in
DEFINE_FWK_MODULE(TrackFromSeedProducer);