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

// $Id: Pearson.cc 1487 2008-09-10 08:41:36Z jari $

/*
  Copyright (C) 2004, 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 "Pearson.h"
#include "AveragerPair.h"
#include "AveragerPairWeighted.h"
#include "yat/utility/VectorBase.h"
#include "yat/classifier/DataLookupWeighted1D.h"
#include "yat/classifier/Target.h"

#include <cmath>

namespace theplu {
namespace yat {
namespace statistics {  

  Pearson::Pearson(bool b) 
    : Score(b)
  {
  }

  Pearson::~Pearson(void)
  {
  }

  double Pearson::score(const classifier::Target& target, 
                        const utility::VectorBase& value) const
  {
    AveragerPair ap;
    for (size_t i=0; i<target.size(); i++){
      if (target.binary(i))
        ap.add(1, value(i));
      else
        ap.add(-1, value(i));
    }
    double r = ap.correlation();
    if (r<0 && absolute_)
      return -r;
    return r;
  } 
    
  double Pearson::score(const classifier::Target& target, 
                        const classifier::DataLookupWeighted1D& value) const
  {
    AveragerPairWeighted ap;
    for (size_t i=0; i<target.size(); i++){
      if (target.binary(i))
        ap.add(1, value.data(i),1,value.weight(i));
      else
        ap.add(-1, value.data(i),1,value.weight(i));
    }
    double r = ap.correlation();
    if (r<0 && absolute_)
      return -r;
    return r;
  }

  double Pearson::score(const classifier::Target& target, 
                        const utility::VectorBase& value,
                        const utility::VectorBase& weight) const
  {
    AveragerPairWeighted ap;
    for (size_t i=0; i<target.size(); i++){
      if (target.binary(i))
        ap.add(1, value(i),1,weight(i));
      else
        ap.add(-1, value(i),1,weight(i));
    } 
    double r = ap.correlation();
    if (r<0 && absolute_)
      return -r;
    return r;
  }

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