source: trunk/yat/statistics/pearson_distance.h @ 1031

#ifndef theplu_yat_statistics_pearson_distance_h
#define theplu_yat_statistics_pearson_distance_h

// $Id: pearson_distance.h 1031 2008-02-04 15:44:44Z markus $

/*
  Copyright (C) 2007 Peter Johansson, Markus Ringnér

  This file is part of the yat library, http://trac.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 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 "distance.h"

#include "AveragerPair.h"
#include "AveragerPairWeighted.h"
#include "yat/utility/iterator_traits.h"

namespace theplu {
namespace yat {

namespace statistics {

  ///
  /// Provides a "label" for
  /// the Pearson distance measure.
  ///
  struct pearson_distance_tag 
    : public distance_tag
  {
    /// \brief tag for pearson distance
    typedef pearson_distance_tag distance;
  };


  ///
  /// implementation for distances between vectors
  /// (containers with random access iterators) using a Pearson
  /// distance measure and iterators to unweighted containers.
  /// 
  template <class Iter>
  double distance(Iter beg1,Iter end1, Iter beg2,
                         const pearson_distance_tag& disttype,
                         utility::unweighted_type)
  {
    AveragerPair ap;
    add(ap,beg1,end1,beg2);
    return 1-ap.correlation();
  }
  
  ///
  /// implementation for distances between vectors
  /// (containers with random access iterators) using a Pearson
  /// distance measure and iterators to unweighted containers.
  /// 
  template <class Iter>
  double distance(Iter beg1,Iter end1, Iter beg2,
                         const pearson_distance_tag& disttype,
                         utility::weighted_type)
  {
    AveragerPairWeighted ap;
    add(ap,beg1,end1,beg2);
    return 1-ap.correlation();
  }

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