SortSegmentsByNumberOfHits.h

Go to the documentation of this file.

/*
  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
*/
 
#ifndef SORTSEGMENTSBYNUMBEROFHITS_H
#define SORTSEGMENTSBYNUMBEROFHITS_H
 
#include "MuonSegment/MuonSegment.h"
#include "TrkEventPrimitives/FitQuality.h"
 
namespace Muon {
 
    class SortSegmentsByNumberOfHits {
    public:
        bool operator()(const std::unique_ptr<MuonSegment>& seg1, const std::unique_ptr<MuonSegment>& seg2) {
            unsigned int nhits1 = seg1->containedMeasurements().size();
            unsigned int nhits2 = seg2->containedMeasurements().size();
            if (nhits1 > nhits2) return true;
            if (nhits1 < nhits2) return false;
 
            // prefer segments with fit quality (always expected)
            const Trk::FitQuality* fq1 = seg1->fitQuality();
            const Trk::FitQuality* fq2 = seg2->fitQuality();
            if (!fq1 && fq2) return false;
            if (fq1 && !fq2) return true;
            if (!fq1 && !fq2) { return true; }
 
            if (fq1->numberDoF() > fq2->numberDoF()) return true;
            if (fq1->numberDoF() < fq2->numberDoF()) return false;
 
            // select candidate with smallest chi2
            double chi2Ndof1 = fq1->chiSquared() / fq1->numberDoF();
            double chi2Ndof2 = fq2->chiSquared() / fq2->numberDoF();
            return chi2Ndof1 < chi2Ndof2;
        }
    };
 
}  // namespace Muon
 
#endif