source: trunk/src/tScore.cc @ 98

// $Id: tScore.cc 98 2004-06-10 15:24:05Z peter $

// System includes
#include <cmath>

// Thep C++ Tools
#include "tScore.h"
#include "vector.h"
#include "Averager.h"

namespace theplu {
namespace cpptools {  

  tScore::tScore( const gslapi::vector& target, 
                  const gslapi::vector& value) 
      : Score(), value_(value), target_(target)
     
  {
  }
    
  double tScore::score()
  {
    Averager positive;
    Averager negative;
    for(size_t i=0; i<target_.size(); i++){
      if (target_[i]==1)
        positive.add(value_[i]);
      else
        negative.add(value_[i]);
    }
    double diff = positive.mean() - negative.mean();
    double s=sqrt((positive.sum_xsqr()+negative.sum_xsqr())
                  /(positive.n()-1+negative.n()-1));
    return diff/s;
  }


  double tScore::p_value(void)
  {
    double t = score();
    double dof = target_.size()-2;
    double p = gsl_cdf_tdist_Q(t, dof);
    return dof > 0 ? p : 1;
  }



}} // of namespace cpptools and namespace theplu