/cvmfs/atlas.cern.ch/repo/sw/ASG/AnalysisBase/2.4.31/tauRecTools/tauRecTools/KineUtils.h

#ifndef TAUREC_KINEUTILS_H
#define TAUREC_KINEUTILS_H


#include <string>
#include "TVector2.h"

//static const double kPI  = 3.1415927;
//static const double k2PI = 2*3.1415927;


class Tau1P3PKineUtils
{
    public:
        static double deltaEta(double eta1, double eta2) { return std::fabs( eta1 - eta2);} 


        /*
        static double deltaPhi(double phi1, double phi2)
        {

            double dphi = std :: fabs( phi1 - phi2 );
            if( dphi  >  kPI ) dphi -= k2PI;
            return std :: fabs( dphi );
        }
        */
        static double deltaPhi(double phi1, double phi2)
        {
            return TVector2::Phi_mpi_pi(phi1-phi2);
        }

        static double deltaR(double de,double dp) { return std::sqrt(de*de+dp*dp); }
        static double deltaR(double eta1, double phi1, double eta2, double phi2) {
            return std::sqrt(deltaEta(eta1,eta2)*deltaEta(eta1,eta2)+deltaPhi(phi1,phi2)*deltaPhi(phi1,phi2));
        }

};

#endif 

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