source: trunk/lib/statistics/FoldChange.cc @ 514

// $Id: FoldChange.cc 514 2006-02-20 09:45:34Z peter $

#include <c++_tools/statistics/FoldChange.h>
#include <c++_tools/statistics/Score.h>
#include <c++_tools/statistics/Averager.h>
#include <c++_tools/statistics/AveragerWeighted.h>
#include <c++_tools/classifier/Target.h>

namespace theplu {
namespace statistics {


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



  FoldChange::FoldChange(const FoldChange& other)
    : Score(other)
  {
  }



  FoldChange& FoldChange::operator=(const FoldChange& other)
  {
    Score::operator=(other);
    return *this;
  }

  double FoldChange::score(const classifier::Target& target, 
                           const gslapi::vector& value) 
  {
    weighted_=false;
    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 fabs(pos.mean()-neg.mean());
    return pos.mean()-neg.mean();
  }

  double FoldChange::score(const classifier::Target& target, 
                           const gslapi::vector& value,
                           const gslapi::vector& weight) 
  {
    weighted_=true;
    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 fabs(pos.mean()-neg.mean());
    return pos.mean()-neg.mean();
  }

} // of namespace statistics
} // of namespace theplu