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

Last change on this file since 1031 was 1031, checked in by Markus Ringnér, 15 years ago

Fixes #272

  • Property svn:eol-style set to native
  • Property svn:keywords set to Id
File size: 2.7 KB
Line 
1#ifndef theplu_yat_statistics_distance_h
2#define theplu_yat_statistics_distance_h
3
4// $Id: distance.h 1031 2008-02-04 15:44:44Z markus $
5
6/*
7  Copyright (C) 2007 Peter Johansson, Markus Ringnér
8
9  This file is part of the yat library, http://trac.thep.lu.se/yat
10
11  The yat library is free software; you can redistribute it and/or
12  modify it under the terms of the GNU General Public License as
13  published by the Free Software Foundation; either version 2 of the
14  License, or (at your option) any later version.
15
16  The yat library is distributed in the hope that it will be useful,
17  but WITHOUT ANY WARRANTY; without even the implied warranty of
18  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19  General Public License for more details.
20
21  You should have received a copy of the GNU General Public License
22  along with this program; if not, write to the Free Software
23  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
24  02111-1307, USA.
25*/
26
27#include <iterator>
28
29#include "yat/classifier/DataLookup1D.h"
30#include "yat/classifier/DataLookupWeighted1D.h"
31#include "yat/utility/iterator_traits.h"
32
33namespace theplu {
34namespace yat {
35
36namespace statistics {
37 
38  ///
39  /// For each measure to calculate distances between containers
40  /// with random access iterators one should provide a struct
41  /// that inherits from distance_tag and provides a "label" for
42  /// the distance measure.
43  ///
44  struct distance_tag {
45    /// tag defining distance measure
46    typedef distance_tag distance;
47  };
48
49
50  ///
51  /// We are writing a generic function for all distance measures
52  /// between containers with random access iterators (below). The
53  /// general function does not have to know anything about different
54  /// distance measures.  Instead it can access the "label" of each
55  /// distance measure through the special template structure
56  /// distance_traits.
57  ///
58  template <class T>
59  struct distance_traits {
60    /// \return distance type
61    typedef typename T::distance distance;
62  };
63
64
65  ///
66  /// The general function for calculating distances between vectors
67  /// (containers with random access iterators). This general function
68  /// calls specialized distance functions implementing various
69  /// distance measures based on the "label" of a distance type object
70  /// (templatized as Dist). It can also call separate implementations
71  /// for iterators to weighted and unweighted iterators based on the
72  /// trait of the iterators (templatized as Iter1 and Iter2).
73  ///
74  template <typename Iter1, typename Iter2, typename Dist>
75  double distance(Iter1 beg1, Iter1 end1, Iter2 beg2, const Dist disttag)
76  {
77    return 
78      distance(beg1,end1,beg2,
79                      typename distance_traits<Dist>::distance(),
80                      typename utility::weighted_if_any2<Iter1, Iter2>::type());
81  }       
82
83}}} // of namespace statistics, yat, and theplu
84
85#endif
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