source: trunk/yat/statistics/pearson_vector_distance.h @ 894

#ifndef theplu_yat_statistics_pearson_vector_distance_h
#define theplu_yat_statistics_pearson_vector_distance_h

// $Id$

#include "vector_distance.h"

#include "AveragerPair.h"

namespace theplu {
namespace yat {

namespace statistics {

  ///
  /// Provides a "label" for
  /// the Pearson distance measure.
  ///
  struct pearson_vector_distance_tag 
    : public vector_distance_tag
  {
    typedef pearson_vector_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 vector_distance(Iter beg1,Iter end1, Iter beg2,
                         const pearson_vector_distance_tag& disttype,
                         std::random_access_iterator_tag)
  {
    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 vector_distance(Iter beg1,Iter end1, Iter beg2,
                         const pearson_vector_distance_tag& disttype,
                         std::weighted_random_access_iterator_tag)
  {
    AveragerPairWeighted ap;
    add(ap,beg1,end1,beg2);
    return 1-ap.correlation();
  }

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