source: trunk/yat/statistics/AveragerPair.cc @ 1746

// $Id: AveragerPair.cc 1746 2009-01-23 16:59:11Z peter $

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

  This file is part of the yat library, http://dev.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 3 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 yat. If not, see <http://www.gnu.org/licenses/>.
*/

#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 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();
  }

  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