SeedTransformer.cc

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/*
 *  See header file for a description of this class.
 *
 *  \author D. Trocino - University and INFN Torino
 */
 
#include "TrackingTools/TrackRefitter/interface/SeedTransformer.h"
 
// System include files
// #include <memory>
// #include <Riostream.h>
 
// Framework
#include "FWCore/Framework/interface/MakerMacros.h"
#include "FWCore/Framework/interface/Frameworkfwd.h"
#include "FWCore/Framework/interface/Event.h"
#include "FWCore/Framework/interface/EventSetup.h"
#include "FWCore/Framework/interface/ESHandle.h"
#include "FWCore/ParameterSet/interface/ParameterSet.h"
#include "FWCore/MessageLogger/interface/MessageLogger.h"
 
// Services and Tools
 
// Geometry and Magnetic field
#include "MagneticField/Records/interface/IdealMagneticFieldRecord.h"
#include "Geometry/Records/interface/GlobalTrackingGeometryRecord.h"
#include "Geometry/CommonDetUnit/interface/GeomDet.h"
#include "Geometry/CommonDetUnit/interface/GlobalTrackingGeometry.h"
 
// Other include files
#include "TrackingTools/Records/interface/TransientRecHitRecord.h"
#include "TrackingTools/TransientTrackingRecHit/interface/TransientTrackingRecHitBuilder.h"
#include "TrackingTools/TrajectoryState/interface/TrajectoryStateOnSurface.h"
#include "TrackingTools/TrajectoryState/interface/TrajectoryStateTransform.h"
#include "TrackingTools/Records/interface/TrackingComponentsRecord.h"
#include "TrackingTools/TrackFitters/interface/TrajectoryFitter.h"
#include "TrackingTools/PatternTools/interface/Trajectory.h"
#include "TrackingTools/GeomPropagators/interface/Propagator.h"
 
#include "RecoMuon/TransientTrackingRecHit/interface/MuonTransientTrackingRecHitBreaker.h"
 
using namespace std;
using namespace edm;
using namespace reco;
 
SeedTransformer::SeedTransformer(const ParameterSet& iConfig) {
  LogTrace("Reco|TrackingTools|SeedTransformer") << "SeedTransformer constructor called." << endl << endl;
 
  theFitterName = iConfig.getParameter<string>("Fitter");
  theMuonRecHitBuilderName = iConfig.getParameter<string>("MuonRecHitBuilder");
  thePropagatorName = iConfig.getParameter<string>("Propagator");
 
  nMinRecHits = iConfig.getParameter<unsigned int>("NMinRecHits");
  errorRescale = iConfig.getParameter<double>("RescaleError");
  useSubRecHits = iConfig.getParameter<bool>("UseSubRecHits");
}
 
SeedTransformer::~SeedTransformer() {
  LogTrace("Reco|TrackingTools|SeedTransformer") << "SeedTransformer destructor called." << endl << endl;
}
 
void SeedTransformer::setServices(const EventSetup& iSetup) {
  iSetup.get<GlobalTrackingGeometryRecord>().get(theTrackingGeometry);
  iSetup.get<IdealMagneticFieldRecord>().get(theMagneticField);
  iSetup.get<TrajectoryFitter::Record>().get(theFitterName, theFitter);
  iSetup.get<TransientRecHitRecord>().get(theMuonRecHitBuilderName, theMuonRecHitBuilder);
  iSetup.get<TrackingComponentsRecord>().get(thePropagatorName, thePropagator);
}
 
vector<Trajectory> SeedTransformer::seedTransform(const TrajectorySeed& aSeed) const {
  const string metname = "Reco|TrackingTools|SeedTransformer";
 
  LogTrace(metname) << " Number of valid RecHits:      " << aSeed.nHits() << endl;
 
  if (aSeed.nHits() < nMinRecHits) {
    LogTrace(metname) << "    --- Too few RecHits, no refit performed! ---" << endl;
    return vector<Trajectory>();
  }
 
  TrajectoryStateOnSurface aTSOS(seedTransientState(aSeed));
 
  // Rescale errors before refit, not to bias the result
  aTSOS.rescaleError(errorRescale);
 
  vector<TransientTrackingRecHit::ConstRecHitPointer> recHits;
 
  for (auto const& recHit : aSeed.recHits()) {
    if (recHit.isValid()) {
      TransientTrackingRecHit::ConstRecHitPointer ttrh(theMuonRecHitBuilder->build(&recHit));
 
      if (useSubRecHits) {
        TransientTrackingRecHit::ConstRecHitContainer subHits =
            MuonTransientTrackingRecHitBreaker::breakInSubRecHits(ttrh, 2);
        copy(subHits.begin(), subHits.end(), back_inserter(recHits));
      } else {
        recHits.push_back(ttrh);
      }
    }
  }
 
  TrajectoryStateOnSurface aInitTSOS = thePropagator->propagate(aTSOS, recHits.front()->det()->surface());
 
  if (!aInitTSOS.isValid()) {
    LogTrace(metname) << "    --- Initial state for refit not valid! ---" << endl;
    return vector<Trajectory>();
  }
 
  vector<Trajectory> refittedSeed = theFitter->fit(aSeed, recHits, aInitTSOS);
 
  if (refittedSeed.empty()) {
    LogTrace(metname) << "    --- Seed fit failed! ---" << endl;
    return vector<Trajectory>();
  }
 
  else if (!refittedSeed.front().isValid()) {
    LogTrace(metname) << "    --- Seed fitted, but trajectory not valid! ---" << endl;
    return vector<Trajectory>();
  }
 
  else
    LogTrace(metname) << "    +++ Seed fit succeded! +++" << endl;
 
  return refittedSeed;
}
 
TrajectoryStateOnSurface SeedTransformer::seedTransientState(const TrajectorySeed& tmpSeed) const {
  PTrajectoryStateOnDet tmpTSOD = tmpSeed.startingState();
  DetId tmpDetId(tmpTSOD.detId());
  const GeomDet* tmpGeomDet = theTrackingGeometry->idToDet(tmpDetId);
 
  TrajectoryStateOnSurface tmpTSOS =
      trajectoryStateTransform::transientState(tmpTSOD, &(tmpGeomDet->surface()), &(*theMagneticField));
 
  return tmpTSOS;
}