CentroidCalculator.hh

 
#ifndef __RAT_CentroidCalculator__
#define __RAT_CentroidCalculator__
#include <TVector3.h>
#include <math.h>
 
namespace RAT {
 
class CentroidCalculator {
 public:
  CentroidCalculator() { Reset(); };
 
  void Reset() {
    fMoment0 = 0.0;
    fMoment1.SetXYZ(0.0, 0.0, 0.0);
    fMoment2.SetXYZ(0.0, 0.0, 0.0);
  };
 
  void Fill(const TVector3 &point, double weight = 1.0) {
    fMoment0 += weight;
    fMoment1 += weight * point;
    TVector3 square(point.X() * point.X(), point.Y() * point.Y(), point.Z() * point.Z());
    fMoment2 += weight * square;
  };
 
  void Add(const CentroidCalculator &other) {
    fMoment0 += other.fMoment0;
    fMoment1 += other.fMoment1;
    fMoment2 += other.fMoment2;
  };
 
  TVector3 GetMean() const { return fMoment1 * (1.0 / fMoment0); };
 
  TVector3 GetRMS() const {
    TVector3 squareMoment1(fMoment1.X() * fMoment1.X(), fMoment1.Y() * fMoment1.Y(), fMoment1.Z() * fMoment1.Z());
    TVector3 temp = fMoment0 * fMoment2 - squareMoment1;
 
    return TVector3(sqrt(temp.X()), sqrt(temp.Y()), sqrt(temp.Z())) * (1.0 / fMoment0);
  };
 
 protected:
  double fMoment0;
  TVector3 fMoment1;
  TVector3 fMoment2;
};
 
}  // namespace RAT
 
#endif