PixelHitMatcher.cc

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#include "RecoEgamma/EgammaElectronAlgos/interface/PixelHitMatcher.h"
#include "RecoEgamma/EgammaElectronAlgos/interface/PixelMatchNextLayers.h"
#include "RecoEgamma/EgammaElectronAlgos/interface/ElectronUtilities.h"
#include "TrackingTools/PatternTools/interface/TrajectoryMeasurement.h"
#include "TrackingTools/DetLayers/interface/DetLayer.h"
#include "TrackingTools/MeasurementDet/interface/LayerMeasurements.h"
#include "RecoTracker/MeasurementDet/interface/MeasurementTracker.h"
#include "RecoTracker/MeasurementDet/interface/MeasurementTrackerEvent.h"
#include "DataFormats/DetId/interface/DetId.h"
#include "DataFormats/GeometryCommonDetAlgo/interface/PerpendicularBoundPlaneBuilder.h"
#include "FWCore/MessageLogger/interface/MessageLogger.h"

#include <typeinfo>
#include <bitset>

using namespace reco ;
using namespace std ;

PixelHitMatcher::PixelHitMatcher
 ( float phi1min, float phi1max,
   float phi2minB, float phi2maxB, float phi2minF, float phi2maxF,
   float z2minB, float z2maxB, float r2minF, float r2maxF,
   float rMinI, float rMaxI, bool searchInTIDTEC)
 : //zmin1 and zmax1 are dummy at this moment, set from beamspot later
   meas1stBLayer(phi1min,phi1max,0.,0.), meas2ndBLayer(phi2minB,phi2maxB,z2minB,z2maxB),
   meas1stFLayer(phi1min,phi1max,0.,0.), meas2ndFLayer(phi2minF,phi2maxF,r2minF,r2maxF),
   startLayers(),
   prop1stLayer(nullptr), prop2ndLayer(nullptr),theGeometricSearchTracker(nullptr),theTrackerEvent(nullptr),theTracker(nullptr),vertex_(0.),
   searchInTIDTEC_(searchInTIDTEC), useRecoVertex_(false)
 {
  meas1stFLayer.setRRangeI(rMinI,rMaxI) ;
  meas2ndFLayer.setRRangeI(rMinI,rMaxI) ;
 }

PixelHitMatcher::~PixelHitMatcher()
 {
  delete prop1stLayer ;
  delete prop2ndLayer ;
 }

void PixelHitMatcher::set1stLayer( float dummyphi1min, float dummyphi1max )
 {
  meas1stBLayer.setPhiRange(dummyphi1min,dummyphi1max) ;
  meas1stFLayer.setPhiRange(dummyphi1min,dummyphi1max) ;
 }

void PixelHitMatcher::set1stLayerZRange( float zmin1, float zmax1 )
 {
  meas1stBLayer.setZRange(zmin1,zmax1) ;
  meas1stFLayer.setRRange(zmin1,zmax1) ;
 }

void PixelHitMatcher::set2ndLayer( float dummyphi2minB, float dummyphi2maxB, float dummyphi2minF, float dummyphi2maxF )
 {
  meas2ndBLayer.setPhiRange(dummyphi2minB,dummyphi2maxB) ;
  meas2ndFLayer.setPhiRange(dummyphi2minF,dummyphi2maxF) ;
 }

void PixelHitMatcher::setUseRecoVertex( bool val )
 { useRecoVertex_ = val ; }

void PixelHitMatcher::setEvent( const MeasurementTrackerEvent & trackerData ) 
 {
    theTrackerEvent = & trackerData;
    theLayerMeasurements = LayerMeasurements(*theTracker,*theTrackerEvent);
 }
void PixelHitMatcher::setES
 ( const MagneticField * magField,
   const MeasurementTracker * theMeasurementTracker,
   const TrackerGeometry * trackerGeometry )
 {
  if (theMeasurementTracker)
   {
    theTracker = theMeasurementTracker;
    theGeometricSearchTracker=theMeasurementTracker->geometricSearchTracker() ;
    startLayers.setup(theGeometricSearchTracker) ;
   }

  theMagField = magField ;
  theTrackerGeometry = trackerGeometry ;
  float mass=.000511 ; // electron propagation
  if (prop1stLayer) delete prop1stLayer ;
  prop1stLayer = new PropagatorWithMaterial(oppositeToMomentum,mass,theMagField) ;
  if (prop2ndLayer) delete prop2ndLayer ;
  prop2ndLayer = new PropagatorWithMaterial(alongMomentum,mass,theMagField) ;
 }

vector<CLHEP::Hep3Vector> PixelHitMatcher::predicted1Hits()
 { return pred1Meas ; }

vector<CLHEP::Hep3Vector> PixelHitMatcher::predicted2Hits()
 { return pred2Meas ; }

float PixelHitMatcher::getVertex()
 { return vertex_ ; }


std::vector<SeedWithInfo>
PixelHitMatcher::compatibleSeeds
( const std::vector<const TrajectorySeedCollection *>& seedsV, const GlobalPoint & xmeas,
   const GlobalPoint & vprim, float energy, float fcharge )
 {
   typedef std::unordered_map<const GeomDet *, TrajectoryStateOnSurface> DetTsosAssoc;
   typedef std::unordered_map<std::pair<const GeomDet*,GlobalPoint>, TrajectoryStateOnSurface> PosTsosAssoc;
   const int charge = int(fcharge) ;

   // auto xmeas_phi = xmeas.barePhi();
   auto xmeas_r = xmeas.perp();
   
   const float phicut = std::cos(2.5);


  FreeTrajectoryState fts = FTSFromVertexToPointFactory::get(*theMagField, xmeas, vprim, energy, charge);
  PerpendicularBoundPlaneBuilder bpb;
  TrajectoryStateOnSurface tsos(fts, *bpb(fts.position(), fts.momentum()));
  
  std::vector<SeedWithInfo> result ;
  unsigned int allSeedsSize = 0;
  for (auto const sc : seedsV) allSeedsSize += sc->size();

  mapTsos2_fast_.clear();  
  mapTsos2_fast_.reserve(allSeedsSize) ;

  // std::vector<TrajectoryStateOnSurface> vTsos(theTrackerGeometry->dets().size());
  // TrajectoryStateOnSurface vTsos[theTrackerGeometry->dets().size()];

  auto ndets = theTrackerGeometry->dets().size();

  int iTsos[ndets];
  for ( auto & i : iTsos) i=-1;
  std::vector<TrajectoryStateOnSurface> vTsos; vTsos.reserve(allSeedsSize);

  for (const auto seeds : seedsV) {
    for(const auto& seed : *seeds) {
      hit_gp_map_.clear();
      if( seed.nHits() > 9 ) {
        edm::LogWarning("GsfElectronAlgo|UnexpectedSeed") <<"We cannot deal with seeds having more than 9 hits." ;
        continue;
      }
      
      const TrajectorySeed::range& hits = seed.recHits();
      // cache the global points
      
      for( auto it = hits.first; it != hits.second; ++it ) {
        hit_gp_map_.emplace_back(it->globalPosition());      
      }
      
      //iterate on the hits 
      auto he =  hits.second -1;   
      for( auto it1 = hits.first; it1 < he; ++it1 ) {
        if( !it1->isValid() ) continue;
        auto  idx1 = std::distance(hits.first,it1);
        const DetId id1 = it1->geographicalId();
        const GeomDet *geomdet1 = it1->det();
        
        auto ix1 = geomdet1->gdetIndex();
        
        /*  VI: this generates regression (other cut is just in phi). in my opinion it is safe and makes sense
            auto away = geomdet1->position().basicVector().dot(xmeas.basicVector()) <0;
            if (away) continue;
        */
        
        const GlobalPoint& hit1Pos = hit_gp_map_[idx1];
        auto dt = hit1Pos.x()*xmeas.x()+hit1Pos.y()*xmeas.y();
        if (dt<0) continue;
        if (dt<phicut*(xmeas_r*hit1Pos.perp())) continue;
        
        if(iTsos[ix1]<0)   {
          iTsos[ix1] = vTsos.size();
          vTsos.push_back(prop1stLayer->propagate(tsos,geomdet1->surface()));
        }
        auto tsos1 = &vTsos[iTsos[ix1]];
        
        if( !tsos1->isValid() ) continue;
        std::pair<bool, double> est = ( id1.subdetId() % 2 ? 
                                        meas1stBLayer.estimate(vprim, *tsos1, hit1Pos) :
                                        meas1stFLayer.estimate(vprim, *tsos1, hit1Pos)  );
        if( !est.first ) continue;
        EleRelPointPair pp1(hit1Pos,tsos1->globalParameters().position(),vprim);
        const math::XYZPoint relHit1Pos(hit1Pos-vprim), relTSOSPos(tsos1->globalParameters().position() - vprim);
        const int subDet1 = id1.subdetId();
        const float dRz1 = ( id1.subdetId()%2 ? pp1.dZ() : pp1.dPerp() );
        const float dPhi1 = pp1.dPhi();
        // setup our vertex
        double zVertex;
        if (!useRecoVertex_) {
          // we don't know the z vertex position, get it from linear extrapolation
          // compute the z vertex from the cluster point and the found pixel hit
          const double pxHit1z = hit1Pos.z();
          const double pxHit1x = hit1Pos.x();
          const double pxHit1y = hit1Pos.y();
          const double r1diff = std::sqrt( (pxHit1x-vprim.x())*(pxHit1x-vprim.x()) + 
                                           (pxHit1y-vprim.y())*(pxHit1y-vprim.y())   );
          const double r2diff = std::sqrt( (xmeas.x()-pxHit1x)*(xmeas.x()-pxHit1x) + 
                                           (xmeas.y()-pxHit1y)*(xmeas.y()-pxHit1y)   );
          zVertex = pxHit1z - r1diff*(xmeas.z()-pxHit1z)/r2diff;
        } else { 
          // here use rather the reco vertex z position
          zVertex = vprim.z(); 
        }
        GlobalPoint vertex(vprim.x(),vprim.y(),zVertex);
        FreeTrajectoryState fts2 = FTSFromVertexToPointFactory::get(*theMagField, hit1Pos, vertex, energy, charge) ;
        // now find the matching hit
        for( auto it2 = it1+1; it2 != hits.second; ++it2 ) {
          if( !it2->isValid() ) continue;
          auto idx2 = std::distance(hits.first,it2);
          const DetId id2 = it2->geographicalId();
          const GeomDet *geomdet2 = it2->det();
          const std::pair<const GeomDet *,GlobalPoint> det_key(geomdet2,hit1Pos);   
          const TrajectoryStateOnSurface* tsos2;
          auto tsos2_itr = mapTsos2_fast_.find(det_key);
          if( tsos2_itr != mapTsos2_fast_.end() ) {
            tsos2 = &(tsos2_itr->second);
          } else {
            auto empl_result =
              mapTsos2_fast_.emplace(det_key,prop2ndLayer->propagate(fts2,geomdet2->surface()));
            tsos2 = &(empl_result.first->second);
          }
          if( !tsos2->isValid() ) continue;
          const GlobalPoint& hit2Pos = hit_gp_map_[idx2];
          std::pair<bool,double> est2  = ( id2.subdetId()%2 ? 
                                           meas2ndBLayer.estimate(vertex, *tsos2,hit2Pos) :
                                           meas2ndFLayer.estimate(vertex, *tsos2,hit2Pos)   );
          if (est2.first) {
            EleRelPointPair pp2(hit2Pos,tsos2->globalParameters().position(),vertex) ;
            const int subDet2 = id2.subdetId();
            const float dRz2 = (subDet2%2==1)?pp2.dZ():pp2.dPerp();
            const float dPhi2 = pp2.dPhi();
            const unsigned char hitsMask = (1<<idx1)|(1<<idx2);
            result.push_back(SeedWithInfo(seed,hitsMask,subDet2,dRz2,dPhi2,subDet1,dRz1,dPhi1)) ;
          }
        }// inner loop on hits
      }// outer loop on hits
    }// loop on seeds  
  }//loop on vector of seeds
  mapTsos2_fast_.clear() ;
 
  return result ;
 }

//========================= OBSOLETE ? =========================

vector< pair< RecHitWithDist, PixelHitMatcher::ConstRecHitPointer > >
PixelHitMatcher::compatibleHits
 ( const GlobalPoint & xmeas,
   const GlobalPoint & vprim,
   float energy, float fcharge,
   const TrackerTopology *tTopo,
   const NavigationSchool& navigationSchool)
 {
  float SCl_phi = xmeas.phi();

  int charge = int(fcharge);
  // return all compatible RecHit pairs (vector< TSiPixelRecHit>)
  vector<pair<RecHitWithDist, ConstRecHitPointer> > result;
  LogDebug("") << "[PixelHitMatcher::compatibleHits] entering .. ";

  vector<TrajectoryMeasurement> validMeasurements;
  vector<TrajectoryMeasurement> invalidMeasurements;

  typedef vector<TrajectoryMeasurement>::const_iterator aMeas;

  pred1Meas.clear();
  pred2Meas.clear();

  typedef vector<const BarrelDetLayer*>::const_iterator BarrelLayerIterator;
  BarrelLayerIterator firstLayer = startLayers.firstBLayer();

  FreeTrajectoryState fts = FTSFromVertexToPointFactory::get(*theMagField,xmeas, vprim, energy, charge);

  PerpendicularBoundPlaneBuilder bpb;
  TrajectoryStateOnSurface tsos(fts, *bpb(fts.position(), fts.momentum()));

  if (tsos.isValid()) {
    vector<TrajectoryMeasurement> pixelMeasurements =
      theLayerMeasurements.measurements(**firstLayer,tsos,
                     *prop1stLayer, meas1stBLayer);

    LogDebug("") <<"[PixelHitMatcher::compatibleHits] nbr of hits compatible with extrapolation to first layer: " << pixelMeasurements.size();
    for (aMeas m=pixelMeasurements.begin(); m!=pixelMeasurements.end(); m++){
     if (m->recHit()->isValid()) {
       float localDphi = normalized_phi(SCl_phi-m->forwardPredictedState().globalPosition().barePhi()) ;
       if(std::abs(localDphi)>2.5)continue;
    CLHEP::Hep3Vector prediction(m->forwardPredictedState().globalPosition().x(),
                  m->forwardPredictedState().globalPosition().y(),
                  m->forwardPredictedState().globalPosition().z());
    LogDebug("") << "[PixelHitMatcher::compatibleHits] compatible hit position " << m->recHit()->globalPosition();
    LogDebug("") << "[PixelHitMatcher::compatibleHits] predicted position " << m->forwardPredictedState().globalPosition();
    pred1Meas.push_back( prediction);

    validMeasurements.push_back(*m);

    LogDebug("") <<"[PixelHitMatcher::compatibleHits] Found a rechit in layer ";
    const BarrelDetLayer *bdetl = dynamic_cast<const BarrelDetLayer *>(*firstLayer);
    if (bdetl) {
      LogDebug("") <<" with radius "<<bdetl->specificSurface().radius();
    }
    else  LogDebug("") <<"Could not downcast!!";
     }
    }


    // check if there are compatible 1st hits in the second layer
    firstLayer++;

    vector<TrajectoryMeasurement> pixel2Measurements =
      theLayerMeasurements.measurements(**firstLayer,tsos,
                     *prop1stLayer, meas1stBLayer);

    for (aMeas m=pixel2Measurements.begin(); m!=pixel2Measurements.end(); m++){
      if (m->recHit()->isValid()) {
    float localDphi = normalized_phi(SCl_phi-m->forwardPredictedState().globalPosition().barePhi()) ;
    if(std::abs(localDphi)>2.5)continue;
        CLHEP::Hep3Vector prediction(m->forwardPredictedState().globalPosition().x(),
                  m->forwardPredictedState().globalPosition().y(),
                  m->forwardPredictedState().globalPosition().z());
    pred1Meas.push_back( prediction);
        LogDebug("")  << "[PixelHitMatcher::compatibleHits] compatible hit position " << m->recHit()->globalPosition() << endl;
        LogDebug("") << "[PixelHitMatcher::compatibleHits] predicted position " << m->forwardPredictedState().globalPosition() << endl;

    validMeasurements.push_back(*m);
    LogDebug("") <<"[PixelHitMatcher::compatibleHits] Found a rechit in layer ";
    const BarrelDetLayer *bdetl = dynamic_cast<const BarrelDetLayer *>(*firstLayer);
    if (bdetl) {
      LogDebug("") <<" with radius "<<bdetl->specificSurface().radius();
    }
    else  LogDebug("") <<"Could not downcast!!";
      }

    }
  }


  // check if there are compatible 1st hits the forward disks
  typedef vector<const ForwardDetLayer*>::const_iterator ForwardLayerIterator;
  ForwardLayerIterator flayer;

  TrajectoryStateOnSurface tsosfwd(fts, *bpb(fts.position(), fts.momentum()));
  if (tsosfwd.isValid()) {

    for (int i=0; i<2; i++) {
      i == 0 ? flayer = startLayers.pos1stFLayer() : flayer = startLayers.neg1stFLayer();

      if (i==0 && xmeas.z() < -100. ) continue;
      if (i==1 && xmeas.z() > 100. ) continue;

      vector<TrajectoryMeasurement> pixelMeasurements =
    theLayerMeasurements.measurements(**flayer, tsosfwd,
                       *prop1stLayer, meas1stFLayer);

      for (aMeas m=pixelMeasurements.begin(); m!=pixelMeasurements.end(); m++){
    if (m->recHit()->isValid()) {
      float localDphi = normalized_phi(SCl_phi-m->forwardPredictedState().globalPosition().barePhi());
      if(std::abs(localDphi)>2.5)continue;
      CLHEP::Hep3Vector prediction(m->forwardPredictedState().globalPosition().x(),
                m->forwardPredictedState().globalPosition().y(),
                m->forwardPredictedState().globalPosition().z());
      pred1Meas.push_back( prediction);

      validMeasurements.push_back(*m);
    }
      }

      //check if there are compatible 1st hits the outer forward disks
      if (searchInTIDTEC_) {
    flayer++;

    vector<TrajectoryMeasurement> pixel2Measurements =
      theLayerMeasurements.measurements(**flayer, tsosfwd,
                         *prop1stLayer, meas1stFLayer);

    for (aMeas m=pixel2Measurements.begin(); m!=pixel2Measurements.end(); m++){
      if (m->recHit()->isValid()) {
        float localDphi = normalized_phi(SCl_phi-m->forwardPredictedState().globalPosition().barePhi()) ;
        if(std::abs(localDphi)>2.5)continue;
        CLHEP::Hep3Vector prediction(m->forwardPredictedState().globalPosition().x(),
                  m->forwardPredictedState().globalPosition().y(),
                  m->forwardPredictedState().globalPosition().z());
        pred1Meas.push_back( prediction);

        validMeasurements.push_back(*m);
      }
      //    else{std::cout<<" hit non valid "<<std::endl; }
    }  //end 1st hit in outer f disk
      }
    }
  }

  // now we have the vector of all valid measurements of the first point
  for (unsigned i=0; i<validMeasurements.size(); i++){

    const DetLayer * newLayer = theGeometricSearchTracker->detLayer(validMeasurements[i].recHit()->det()->geographicalId());

    double zVertex ;
    if (!useRecoVertex_)
     {
      // we don't know the z vertex position, get it from linear extrapolation
      // compute the z vertex from the cluster point and the found pixel hit
      double pxHit1z = validMeasurements[i].recHit()->det()->surface().toGlobal(
        validMeasurements[i].recHit()->localPosition()).z();
      double pxHit1x = validMeasurements[i].recHit()->det()->surface().toGlobal(
        validMeasurements[i].recHit()->localPosition()).x();
      double pxHit1y = validMeasurements[i].recHit()->det()->surface().toGlobal(
        validMeasurements[i].recHit()->localPosition()).y();
      double r1diff = (pxHit1x-vprim.x())*(pxHit1x-vprim.x()) + (pxHit1y-vprim.y())*(pxHit1y-vprim.y());
      r1diff=sqrt(r1diff);
      double r2diff = (xmeas.x()-pxHit1x)*(xmeas.x()-pxHit1x) + (xmeas.y()-pxHit1y)*(xmeas.y()-pxHit1y);
      r2diff=sqrt(r2diff);
      zVertex = pxHit1z - r1diff*(xmeas.z()-pxHit1z)/r2diff;
     }
    else
     {
      // here we use the reco vertex z position
      zVertex = vprim.z();
     }

    if (i==0)
     { vertex_ = zVertex; }

    GlobalPoint vertexPred(vprim.x(),vprim.y(),zVertex) ;
    GlobalPoint hitPos( validMeasurements[i].recHit()->det()->surface().toGlobal( validMeasurements[i].recHit()->localPosition() ) ) ;

    FreeTrajectoryState secondFTS = FTSFromVertexToPointFactory::get(*theMagField, hitPos, vertexPred, energy, charge);

    PixelMatchNextLayers secondHit(&theLayerMeasurements, newLayer, secondFTS,
                   prop2ndLayer, &meas2ndBLayer,&meas2ndFLayer,
                   tTopo,navigationSchool,searchInTIDTEC_);
    vector<CLHEP::Hep3Vector> predictions = secondHit.predictionInNextLayers();

    for (unsigned it = 0; it < predictions.size(); it++) pred2Meas.push_back(predictions[it]);

    // we may get more than one valid second measurements here even for single electrons:
    // two hits from the same layer/disk (detector overlap) or from the loop over the
    // next layers in EPMatchLoopNextLayers. Take only the 1st hit.

    if(!secondHit.measurementsInNextLayers().empty()){
      for(unsigned int shit=0; shit<secondHit.measurementsInNextLayers().size(); shit++)
        {
      float dphi = normalized_phi(pred1Meas[i].phi()-validMeasurements[i].recHit()->globalPosition().barePhi()) ;
      if (std::abs(dphi)<2.5)
        {
          ConstRecHitPointer pxrh = validMeasurements[i].recHit();
          RecHitWithDist rh(pxrh,dphi);

          //  pxrh = secondHit.measurementsInNextLayers()[0].recHit();
          pxrh = secondHit.measurementsInNextLayers()[shit].recHit();

          pair<RecHitWithDist,ConstRecHitPointer> compatiblePair = pair<RecHitWithDist,ConstRecHitPointer>(rh,pxrh) ;
          result.push_back(compatiblePair);
          break;
        }
    }
    }
  }
  return result;
}