source: trunk/yat/statistics/AveragerPairWeighted.cc @ 781

// $Id: AveragerPairWeighted.cc 781 2007-03-05 19:44:03Z peter $

/*
  Copyright (C) The authors contributing to this file.

  This file is part of the yat library, http://lev.thep.lu.se/trac/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 "AveragerPairWeighted.h"
#include "AveragerPair.h"
#include "Averager.h"
#include "yat/classifier/DataLookup1D.h"
#include "yat/classifier/DataLookupWeighted1D.h"

#include <cassert>

namespace theplu {
namespace yat {
namespace statistics {


  AveragerPairWeighted::AveragerPairWeighted(void)
    : wxy_(0), w_(0)
  {
  }


  void  AveragerPairWeighted::add(const double x, const double y, 
                                  const double wx, const double wy)
  { 
    if(wx==0.0 || wy==0.0) {
      return;
    }
    double w=wx*wy;
    x_.add(x,w);
    y_.add(y,w); 
    wxy_ += w*x*y;    
    w_ +=w;
  }


  void AveragerPairWeighted::add(const classifier::DataLookup1D& x, 
                                 const classifier::DataLookupWeighted1D& y)
  {
    assert(x.size()==y.size());
    for (size_t i=0; i<x.size(); ++i)
      add(x(i), y.data(i), 1.0, y.weight(i));
  }


  void AveragerPairWeighted::add(const classifier::DataLookupWeighted1D& x, 
                                 const classifier::DataLookup1D& y)
  {
    add(y,x);
  }


  void AveragerPairWeighted::add(const classifier::DataLookupWeighted1D& x, 
                                 const classifier::DataLookupWeighted1D& y)
  {
    assert(x.size()==y.size());
    for (size_t i=0; i<x.size(); ++i)
      add(x.data(i), y.data(i), x.weight(i), y.weight(i));
  }


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


  double AveragerPairWeighted::covariance(void) const
  {
    return sum_xy_centered()/sum_w();
  }


  double AveragerPairWeighted::msd(void) const
  {
    return ( x_.sum_wxx()+y_.sum_wxx()-2*wxy_)/w_;
  }


  void AveragerPairWeighted::reset(void)
  {
    x_.reset(); y_.reset(); wxy_=0; w_=0;
  }

  double AveragerPairWeighted::sum_w(void) const
  {
    return w_;
  }


  double AveragerPairWeighted::sum_xy(void) const
  {
    return wxy_;
  }


  double AveragerPairWeighted::sum_xy_centered(void) const
  {
    return sum_xy() - x_.sum_wx()*y_.mean();
  }


  const AveragerWeighted& AveragerPairWeighted::x_averager(void) const
  {
    return x_;
  }


  const AveragerWeighted& AveragerPairWeighted::y_averager(void) const
  {
    return y_;
  }

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