HarmonicMoments.h

/**************************************************************************
 * BASF2 (Belle Analysis Framework 2)                                     *
 * Copyright(C) 2018 - Belle II Collaboration                             *
 *                                                                        *
 * Author: The Belle II Collaboration                                     *
 * Contributors: Umberto Tamponi (tamponi@to.infn.it)                     *
 *                                                                        *
 * This software is provided "as is" without any warranty.                *
 **************************************************************************/
 
#pragma once
#include <TVector3.h>
#include <vector>
 
 
namespace Belle2 {
  class HarmonicMoments {
  public:
 
    HarmonicMoments()
    {
      m_axis.SetXYZ(0., 0., 0.);
    };
 
    HarmonicMoments(const std::vector<TVector3>& momenta, const TVector3& axis)
    {
      m_momenta.clear();
      m_momenta = momenta;
      m_axis = axis;
    };
 
    ~HarmonicMoments() {};
 
    void setMomenta(const std::vector<TVector3>& momenta)
    {
      m_momenta.clear();
      m_momenta = momenta;
      return;
    };
 
    void setAxis(TVector3 axis)
    {
      m_axis = axis;
      return;
    };
 
    void calculateBasicMoments();
 
    void calculateAllMoments();
 
    double getMoment(short i, double sqrts) const
    {
      if (i < 0 || i > 8)
        return NAN;
      else
        return m_moment[i] / sqrts;
    }
 
  private:
    double m_moment[9] = {0.}; 
    std::vector<TVector3> m_momenta; 
    TVector3 m_axis; 
  };
 
} // Belle2 namespace