SeedFromGenericPairOrTriplet.cc

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#include "RecoTracker/SpecialSeedGenerators/interface/SeedFromGenericPairOrTriplet.h"
#include "RecoTracker/TkSeedGenerator/interface/FastHelix.h"
#include "DataFormats/GeometryVector/interface/GlobalPoint.h"
#include "DataFormats/SiStripDetId/interface/StripSubdetector.h"
#include "FWCore/MessageLogger/interface/MessageLogger.h"
#include "Geometry/CommonDetUnit/interface/GeomDet.h"
#include "TrackingTools/TrajectoryState/interface/TrajectoryStateOnSurface.h"
#include "TrackingTools/TransientTrackingRecHit/interface/TransientTrackingRecHit.h"
#include "TrackingTools/KalmanUpdators/interface/KFUpdator.h"

SeedFromGenericPairOrTriplet::SeedFromGenericPairOrTriplet(const MagneticField* mf,
                                                           const TrackerGeometry* geom,
                               const TransientTrackingRecHitBuilder* builder,
                               const Propagator* propagatorAlong,
                               const Propagator* propagatorOpposite,
                               const std::vector<int>& charges,
                               bool momFromPSet,
                               double errorRescaling):theMagfield(mf), theTracker(geom), theBuilder(builder), thePropagatorAlong(propagatorAlong), thePropagatorOpposite(propagatorOpposite), theSetMomentum(momFromPSet), theCharges(charges), theErrorRescaling(errorRescaling){}


std::vector<TrajectorySeed*> SeedFromGenericPairOrTriplet::seed(const SeedingHitSet& hits,
                                                    const PropagationDirection& dir,
                                                        const NavigationDirection&  seedDir,
                                                        const edm::EventSetup& iSetup){
    std::vector<TrajectorySeed*> seeds;
    if (hits.size() == 3) {
        if(!theSetMomentum){
            TrajectorySeed* seed = seedFromTriplet(hits, dir, seedDir, iSetup);
            if (seed) seeds.push_back(seed);
        } else {
            for (std::vector<int>::const_iterator iCh = theCharges.begin(); iCh != theCharges.end(); iCh++){
                TrajectorySeed* seed = seedFromTriplet(hits, dir, seedDir, iSetup, *iCh);
                if(seed) seeds.push_back(seed);
            }
        } 
        
    } else if (hits.size() == 2){
        if(!theSetMomentum){
            TrajectorySeed* seed = seedFromPair(hits, dir, seedDir);
                        if (seed) seeds.push_back(seed);
                } else {
                        for (std::vector<int>::const_iterator iCh = theCharges.begin(); iCh != theCharges.end(); iCh++){
                TrajectorySeed* seed = seedFromPair(hits, dir, seedDir, *iCh);
                                if (seed) seeds.push_back(seed);
                        }
                }
    } else {
        throw cms::Exception("CombinatorialSeedGeneratorForCosmics") << " Wrong number of hits in Set: "
                                                        << hits.size() << ", should be 2 or 3 ";    
    }
    return seeds;
}

TrajectorySeed* SeedFromGenericPairOrTriplet::seedFromTriplet(const SeedingHitSet& hits,
                                  const PropagationDirection& dir,
                                  const NavigationDirection&  seedDir,
                                  const edm::EventSetup& iSetup, int charge) const{
    if (hits.size() != 3) {
        throw cms::Exception("CombinatorialSeedGeneratorForCosmics") <<
            "call to SeedFromGenericPairOrTriplet::seedFromTriplet with " << hits.size() << " hits ";
    }

        auto innerHit  = hits[0];
        auto middleHit = hits[1];
        auto outerHit  = hits[2];
        GlobalPoint inner  = theTracker->idToDet(innerHit->geographicalId() )->surface().toGlobal(innerHit->localPosition() );
        GlobalPoint middle = theTracker->idToDet(middleHit->geographicalId())->surface().toGlobal(middleHit->localPosition());
        GlobalPoint outer  = theTracker->idToDet(outerHit->geographicalId() )->surface().toGlobal(outerHit->localPosition() );
    if (theSetMomentum){
        LogDebug("SeedFromGenericPairOrTriplet") << 
            "Using the following hits: outer(r, phi, theta) " << outerHit->geographicalId().subdetId()<< " (" << outer.perp() 
            << ", " << outer.phi() 
            << "," << outer.theta() 
            << ")    " << middleHit->geographicalId().subdetId() << " middle (" 
            << middle.perp() << ", " 
            << middle.phi() << "," 
            << middle.theta() << ")    " 
            <<innerHit->geographicalId().subdetId() <<" inner (" 
            << inner.perp() 
            << ", " << inner.phi() 
            << "," << inner.theta() <<")   "
            << "   (x, y, z)   outer ("  
            << inner.x() << ", " 
            << inner.y() << ", " 
            << inner.z() << ")    middle ("  
            << middle.x() << ", " 
                        << middle.y() << ", " 
                        << middle.z() << ")";
        if (!qualityFilter(hits)) return nullptr;
        bool sdir = (seedDir == outsideIn);
                SeedingHitSet newSet(sdir ? hits[1] : hits[0], sdir ? hits[2] : hits[1]); 
        TrajectorySeed* seed = seedFromPair(newSet, dir, seedDir, charge);
        return seed;
                        
    }
    GlobalPoint* firstPoint  = nullptr;
    GlobalPoint* secondPoint = nullptr;
    GlobalPoint* thirdPoint  = nullptr;
    int momentumSign         = 1;
    //const TrackingRecHit* firstHit  = 0;
    //const TrackingRecHit* secondHit = 0;
    //choose the prop dir and hit order accordingly to where the seed is made
    std::vector<const BaseTrackerRecHit*> trHits;
    if (seedDir == outsideIn){
        LogDebug("SeedFromGenericPairOrTriplet") 
            << "Seed from outsideIn alongMomentum OR insideOut oppositeToMomentum";
        firstPoint = &outer;
        secondPoint = &middle;
        thirdPoint = &inner;
        trHits.push_back(outerHit);
        trHits.push_back(middleHit);
        //firstHit  = outerHit;
        //secondHit = middleHit;
    } else {
        LogDebug("SeedFromGenericPairOrTriplet") 
            << "Seed from outsideIn oppositeToMomentum OR insideOut alongMomentum";
        firstPoint = &inner;
        secondPoint = &middle;
        thirdPoint = &outer;
        trHits.push_back(innerHit);
        trHits.push_back(middleHit);
        //firstHit  = innerHit;
        //secondHit = middleHit;
        }
    if (dir == oppositeToMomentum) momentumSign = -1; 
    FastHelix helix(*thirdPoint, *secondPoint, *firstPoint, theMagfield->nominalValue(),theMagfield);
        FreeTrajectoryState originalStartingState = helix.stateAtVertex();
    LogDebug("SeedFromGenericPairOrTriplet") << "originalStartingState " << originalStartingState;
        /*GlobalTrajectoryParameters originalPar = originalStartingState.parameters();
        GlobalTrajectoryParameters newPar = GlobalTrajectoryParameters(originalPar.position(), 
                                                                       momentumSign*originalPar.momentum(),
                                                                       originalPar.charge(),
                                                                       &originalPar.magneticField());
    */
    
    /*FastCircle helix(*thirdPoint, *secondPoint, *firstPoint);
    GlobalTrajectoryParameters newPar = GlobalTrajectoryParameters(*secondPoint,
                                                                       momentumSign*originalPar.momentum(),
                                                                       originalPar.charge(),
                                                                       &originalPar.magneticField());*/
        //FreeTrajectoryState* startingState = new FreeTrajectoryState(newPar, initialError(trHits[0]));//trHits[1]));
    if (!qualityFilter(momentumSign*originalStartingState.momentum())) return nullptr;
    //TrajectorySeed* seed = buildSeed(startingState, trHits, dir);
    TrajectorySeed* seed = buildSeed(momentumSign*originalStartingState.momentum(),originalStartingState.charge(), trHits, dir);
    return seed;    
}

TrajectorySeed* SeedFromGenericPairOrTriplet::seedFromPair(const SeedingHitSet& hits,
                                                           const PropagationDirection& dir,
                               const NavigationDirection&  seedDir, int charge) const{
    if (hits.size() != 2) {
                throw cms::Exception("CombinatorialSeedGeneratorForCosmics") <<
                        "call to SeedFromGenericPairOrTriplet::seedFromPair with " << hits.size() << " hits ";
        }
    auto innerHit = hits[0];
        auto outerHit = hits[1];
        GlobalPoint inner  = theTracker->idToDet(innerHit->geographicalId() )->surface().toGlobal(innerHit->localPosition() );
        GlobalPoint outer  = theTracker->idToDet(outerHit->geographicalId() )->surface().toGlobal(outerHit->localPosition() );
    LogDebug("SeedFromGenericPairOrTriplet") <<
                        "Using the following hits: outer(r, phi, theta) (" << outer.perp()
                        << ", " << outer.phi()
                        << "," << outer.theta()
                        <<")    inner ("
                        << inner.perp()
                        << ", " << inner.phi()
                        << "," << inner.theta() <<")";
    GlobalPoint* firstPoint  = nullptr;
        GlobalPoint* secondPoint = nullptr;
        int momentumSign         = 1;
        //const TrackingRecHit* firstHit  = 0;
        //const TrackingRecHit* secondHit = 0;
    std::vector<const BaseTrackerRecHit*> trHits;
        //choose the prop dir and hit order accordingly to where the seed is made
        if (seedDir == outsideIn){
        LogDebug("SeedFromGenericPairOrTriplet")
                        << "Seed from outsideIn alongMomentum OR insideOut oppositeToMomentum";
                firstPoint = &outer;
                secondPoint = &inner;
                //firstHit  = outerHit;
        //secondHit = innerHit;
        trHits.push_back(outerHit);
        trHits.push_back(innerHit);
        } else {
        LogDebug("SeedFromGenericPairOrTriplet")
                        << "Seed from outsideIn oppositeToMomentum OR insideOut alongMomentum";
                firstPoint = &inner;
                secondPoint = &outer;
                momentumSign = -1;
                //firstHit  = innerHit;
        //secondHit = outerHit;
        trHits.push_back(innerHit);
        trHits.push_back(outerHit);
        }
    if (dir == oppositeToMomentum) momentumSign = -1;
    GlobalVector momentum = momentumSign*theP*(*secondPoint-*firstPoint).unit();
        /*GlobalTrajectoryParameters gtp(*firstPoint, 
                                       momentum,
                                       charge,
                                       &(*theMagfield));*/
        //FreeTrajectoryState* startingState = new FreeTrajectoryState(gtp,initialError(trHits[0]));//trHits[1]));
    //if (!qualityFilter(startingState, hits)) return 0;
        //TrajectorySeed* seed = buildSeed(startingState, firstHit, dir);
        //TrajectorySeed* seed = buildSeed(startingState, trHits, dir);
        TrajectorySeed* seed = buildSeed(momentum, charge, trHits, dir);
        return seed;
}


TrajectorySeed* SeedFromGenericPairOrTriplet::buildSeed(const GlobalVector& momentum,
                            int charge, 
                            //const TrackingRecHit* firsthit,
                            std::vector<const BaseTrackerRecHit*>& trHits,
                            const PropagationDirection& dir) const {
    const Propagator* propagator = thePropagatorAlong;
    if (dir == oppositeToMomentum) propagator = thePropagatorOpposite;

    //debug
    GlobalPoint first = theTracker->idToDet(trHits[0]->geographicalId() )->surface().toGlobal(trHits[0]->localPosition() );
        GlobalPoint second  = theTracker->idToDet(trHits[1]->geographicalId() )->surface().toGlobal(trHits[1]->localPosition() );
        LogDebug("SeedFromGenericPairOrTriplet") <<
                        "Using the following hits: first(r, phi, theta) (" << first.perp()
                        << ", " << first.phi()
                        << "," << first.theta()
                        <<")    second ("
                        << second.perp()
                        << ", " << second.phi()
                        << "," << second.theta() <<")";
    //build an initial trajectory state with big errors, 
    //then update it with the first hit
    auto transHit = trHits[0];
    LocalVector lmom = transHit->surface()->toLocal(momentum);
    LocalTrajectoryParameters ltp(charge/momentum.mag(),
                              lmom.x()/lmom.z(),lmom.y()/lmom.z(),
                              transHit->localPosition().x(),
                              transHit->localPosition().y(),
                              lmom.z()>0.?1.:-1.); 

    LocalTrajectoryError lte(100.,100.,
                        (1.+(lmom.x()/lmom.z())*(lmom.x()/lmom.z())),
                        (1.+(lmom.y()/lmom.z())*(lmom.y()/lmom.z())),
                        1./momentum.mag());
    
    TrajectoryStateOnSurface initialState(ltp,lte,*transHit->surface(),&(*theMagfield));
    KFUpdator updator;
    TrajectoryStateOnSurface startingState = updator.update(initialState,*transHit);

    auto transHit2 = trHits[1];

    //TrajectoryStateOnSurface seedTSOS(*startingState, *plane);
    const TrajectoryStateOnSurface propTSOS = propagator->propagate(startingState,*(transHit2->surface()));
    if (!propTSOS.isValid()){
        LogDebug("SeedFromGenericPairOrTriplet") << "first propagation failed";
        return nullptr;
    }
    TrajectoryStateOnSurface seedTSOS = updator.update(propTSOS, *transHit2);
    if (!seedTSOS.isValid()){
        LogDebug("SeedFromGenericPairOrTriplet") << "first update failed";
                return nullptr;
    }   
    LogDebug("SeedFromGenericPairOrTriplet") << "starting TSOS " << seedTSOS ;
    seedTSOS.rescaleError(theErrorRescaling);
    PTrajectoryStateOnDet PTraj=
        trajectoryStateTransform::persistentState(seedTSOS, trHits[1]->geographicalId().rawId());
    edm::OwnVector<TrackingRecHit> seed_hits;
    //build the transientTrackingRecHit for the starting hit, then call the method clone to rematch if needed
    for (auto ihits = trHits.begin(); ihits != trHits.end(); ihits++){
        seed_hits.push_back((*ihits)->clone());
    }
    TrajectorySeed* seed = new TrajectorySeed(PTraj,seed_hits,dir);
    return seed;
}
/*
CurvilinearTrajectoryError SeedFromGenericPairOrTriplet::initialError(const TrackingRecHit* rechit) {
        SeedingHitSet::RecHitPointer transHit =  theBuilder->build(rechit);
        //AlgebraicSymMatrix C(5,1);
    AlgebraicSymMatrix55 C = AlgebraicMatrixID();
        //C*=0.1;
        if (theSetMomentum){
        C(0,0)=1/theP;
                C(3,3)=transHit->globalPositionError().cxx();
                C(4,4)=transHit->globalPositionError().czz();
        
                //C[0][0]=1/theP;
                //C[3][3]=transHit->globalPositionError().cxx();
                //C[4][4]=transHit->globalPositionError().czz();
        } else {
                float zErr = transHit->globalPositionError().czz();
                float transverseErr = transHit->globalPositionError().cxx(); // assume equal cxx cyy
        C(3,3) = transverseErr;
                C(4,4) = zErr;
                //C[3][3] = transverseErr;
                //C[4][4] = zErr;
        }

        return CurvilinearTrajectoryError(C);
}
*/
bool SeedFromGenericPairOrTriplet::qualityFilter(const SeedingHitSet& hits) const{
    //if we are setting the momentum with the PSet we look for aligned hits
        if (theSetMomentum){
                if (hits.size()==3){
                        std::vector<GlobalPoint> gPoints;
                        unsigned int nHits = hits.size();
                        for (unsigned int iHit = 0; iHit < nHits; ++iHit) gPoints.push_back(hits[iHit]->globalPosition());
                        unsigned int subid=(*hits[0]).geographicalId().subdetId();
            if(subid == StripSubdetector::TEC || subid == StripSubdetector::TID){
                                LogDebug("SeedFromGenericPairOrTriplet") 
                    << "In the endcaps we cannot decide if hits are aligned with only phi and z";
                return true;
                        }
                        FastCircle circle(gPoints[0],
                                          gPoints[1],
                                          gPoints[2]);
                        if (circle.rho() < 500 && circle.rho() != 0) {
                                LogDebug("SeedFromGenericPairOrTriplet") <<
                                        "Seed qualityFilter rejected because rho = " << circle.rho();
                                return false;
                        }

                }
        }
        return true;
}

bool SeedFromGenericPairOrTriplet::qualityFilter(const GlobalVector& momentum) const{
    if (!theSetMomentum){
        if (momentum.perp() < theP) return false;
    }
    return true; 
}