source: branches/0.4-stable/yat/statistics/AveragerPair.cc @ 1294

// $Id: AveragerPair.cc 1294 2008-05-12 08:21:19Z jari $

/*
  Copyright (C) 2004, 2005 Jari Häkkinen, Peter Johansson
  Copyright (C) 2006 Jari Häkkinen, Peter Johansson, Markus Ringnér
  Copyright (C) 2007 Jari Häkkinen, Peter Johansson
  Copyright (C) 2008 Peter Johansson

  This file is part of the yat library, http://trac.thep.lu.se/yat

  The yat library is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License as
  published by the Free Software Foundation; either version 2 of the
  License, or (at your option) any later version.

  The yat library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  02111-1307, USA.
*/

#include "AveragerPair.h"
#include "Averager.h"

#include <cassert>
#include <utility>

namespace theplu {
namespace yat {
namespace statistics {

  AveragerPair::AveragerPair(void)
    : x_(Averager()), y_(Averager()), xy_(0.0)
  {
  }

  AveragerPair::AveragerPair(const AveragerPair& a)
    : x_(a.x_averager()), y_(a.y_averager()), xy_(a.sum_xy())
  {
  }

  void AveragerPair::add(const double x, const double y, const unsigned long n)
  {
    x_.add(x,n); y_.add(y,n); xy_ += n*x*y;
  }

  double AveragerPair::ccc(void) const
  {
    return ((2*covariance()) /
            ((x_.variance()+y_.variance()) +
             (x_.mean()-y_.mean())*(x_.mean()-y_.mean())));
  }

  double AveragerPair::correlation(void) const
  { return covariance() / std::sqrt(x_.variance()*y_.variance());
  }

  double AveragerPair::covariance(void) const
  {
    return (xy_ - x_.sum_x()*y_.mean()) / n();
  }

  double AveragerPair::mean_xy(void) const
  {
    return xy_/n();
  }

  double AveragerPair::msd(void) const
  {
    return sum_squared_deviation()/n();
  }

  unsigned long AveragerPair::n(void) const
  {
    return x_.n();
  }

  void AveragerPair::reset(void)
  {
    x_.reset(); y_.reset(); xy_=0.0;
  }

  const AveragerPair& AveragerPair::operator=(const AveragerPair& a)
  {
    x_=a.x_; y_=a.y_; xy_=a.xy_;
    return *this;
  }

  double AveragerPair::sum_squared_deviation(void) const
  {
    return x_averager().sum_xx()+y_averager().sum_xx()-2*sum_xy() ;
  }

  double AveragerPair::sum_xy(void) const
  {
    return xy_;
  }

  double AveragerPair::sum_xy_centered(void) const
  {
    return xy_-x_.sum_x()*y_.mean();
  }

  const Averager& AveragerPair::x_averager(void) const
  {
    return x_;
  }

  const Averager& AveragerPair::y_averager(void) const
  {
    return y_;
  }

  const AveragerPair& AveragerPair::operator+=(const AveragerPair& a)
  {
    x_+=a.x_averager();
    y_+=a.y_averager();
    xy_+=a.sum_xy();
    return *this;
  }

}}} // of namespace statistics, yat, and theplu