source: trunk/yat/statistics/FoldChange.cc @ 1703

// $Id: FoldChange.cc 1683 2008-12-30 15:42:06Z peter $

/*
  Copyright (C) 2005 Peter Johansson
  Copyright (C) 2006, 2007 Jari Häkkinen, Peter Johansson
  Copyright (C) 2008 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 "FoldChange.h"
#include "Score.h"
#include "Averager.h"
#include "AveragerWeighted.h"
#include "yat/classifier/DataLookupWeighted1D.h"
#include "yat/classifier/Target.h"
#include "yat/utility/VectorBase.h"

#include <cmath>

namespace theplu {
namespace yat {
namespace statistics {

  FoldChange::FoldChange(bool absolute)
    : Score(absolute)
  {
  }

  double FoldChange::score(const classifier::Target& target, 
                           const utility::VectorBase& value) const
  {
    Averager pos;
    Averager neg;

    for (size_t i=0; i<value.size(); i++) 
      if (target.binary(i))
        pos.add(value(i));
      else
        neg.add(value(i));
          
    if (absolute_)
      return std::abs(pos.mean()-neg.mean());
    return pos.mean()-neg.mean();
  }

  double FoldChange::score(const classifier::Target& target, 
                           const classifier::DataLookupWeighted1D& value) const
  {
    AveragerWeighted pos;
    AveragerWeighted neg;

    for (size_t i=0; i<value.size(); i++) 
      if (target.binary(i))
        pos.add(value.data(i),value.weight(i));
      else
        neg.add(value.data(i),value.weight(i));
          
    if (absolute_)
      return std::abs(pos.mean()-neg.mean());
    return pos.mean()-neg.mean();
  }

  double FoldChange::score(const classifier::Target& target, 
                           const utility::VectorBase& value,
                           const utility::VectorBase& weight) const
  {
    AveragerWeighted pos;
    AveragerWeighted neg;

    for (size_t i=0; i<value.size(); i++) 
      if (target.binary(i))
        pos.add(value(i),weight(i));
      else
        neg.add(value(i),weight(i));
          
    if (absolute_)
      return std::abs(pos.mean()-neg.mean());
    return pos.mean()-neg.mean();
  }

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