source: trunk/src/Averager.cc @ 95

// $Id: Averager.cc 95 2004-06-09 16:01:43Z peter $

#include <sys/types.h>

#include <ostream>

#include "Averager.h"

namespace theplu {
namespace cpptools{
  

  Averager::Averager(void)
    : n_(0), x_(0), xx_(0)
  {
  }

  Averager::Averager(double x)
    : n_(1), x_(x), xx_(x*x)
  {
  }

  Averager::Averager(double x,double xx,long n)
    : n_(n), x_(x), xx_(xx)
  {
  }

  Averager::Averager(const Averager& a)
    : n_(a.n_), x_(a.x_), xx_(a.xx_)
  {
  }

  const Averager& Averager::operator+=(const Averager& a)
  {
    n_+=a.n_;
    x_+=a.x_;
    xx_+=a.xx_;
    return *this;
  }

  const Averager& Averager::operator*=(const Averager& N)
  {
    long    Rn=10;
    double  NM=N.mean();
    double  M=mean();
    double  x=M*NM;
    double  var=(variance()*NM*NM+N.variance()*M*M);

    *this=Averager(Rn ,Rn*x ,var*Rn*(Rn-1)+x*x*Rn);
    return *this;
  }

  const Averager& Averager::operator/=(const Averager& N)
  {
    long    Rn=10;
    double  NM=N.mean();
    
    if(NM) {
      double x=mean()/NM;
      double var=(variance()+N.variance()*x*x)/(NM*NM);
      *this=Averager(Rn ,Rn*x ,var*Rn*(Rn-1)+x*x*Rn);
    }
    else
      reset();
    
    return *this;
  }
  
  Averager operator*(double d,const Averager& a) {
    Averager tmp=a;
    return tmp*=d;
  }

  std::ostream& theplu::cpptools::operator<<(std::ostream& o, const Averager& a) 
  {
    return o << a.mean() << ' ' << a.standard_error();
  }

}} // of namespace cpptools and namespace theplu