source: trunk/yat/classifier/IGP.h @ 1120

Last change on this file since 1120 was 1120, checked in by Peter, 14 years ago

vector is now Vector

  • Property svn:eol-style set to native
  • Property svn:keywords set to Author Date ID
File size: 2.9 KB
Line 
1#ifndef _theplu_yat_classifier_igp_
2#define _theplu_yat_classifier_igp_
3
4// $Id$
5
6/*
7  Copyright (C) 2006 Jari Häkkinen, Markus Ringnér, Peter Johansson
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 "DataLookup1D.h"
28#include "MatrixLookup.h"
29#include "Target.h"
30#include "yat/utility/Vector.h"
31#include "yat/utility/yat_assert.h"
32
33#include <cmath>
34#include <limits>
35#include <stdexcept>
36
37namespace theplu {
38namespace yat {
39namespace classifier { 
40
41  class Target;
42  class MatrixLookup;
43
44  ///
45  /// @brief Class for In Group Proportions (IGP)
46  /// See Kapp and Tibshirani, Biostatistics (2006).
47  ///
48  template <typename Distance>
49  class IGP
50  {
51 
52  public:
53    ///
54    /// Constructor taking the training data, the target vector and
55    /// the distance measure as input.
56    ///
57    IGP(const MatrixLookup&, const Target&);
58
59    ///
60    /// Destrucutor
61    ///
62    virtual ~IGP();
63
64    ///
65    /// @return the IGP score for each class as elements in a vector.
66    ///
67    const utility::Vector& score(void) const;
68
69
70  private:
71    utility::Vector igp_;
72    Distance distance_;
73
74    const MatrixLookup& matrix_;
75    const Target& target_;
76  }; 
77
78 
79  // templates
80
81  template <typename Distance>
82  IGP<Distance>::IGP(const MatrixLookup& data, const Target& target) 
83    : matrix_(data), target_(target)
84  {   
85    utility::yat_assert<std::runtime_error>(target_.size()==matrix_.columns());
86   
87    // Calculate IGP for each class
88    igp_ = utility::Vector(target_.nof_classes());
89   
90    for(u_int i=0; i<target_.size(); i++) {
91      u_int neighbor=i;
92      double mindist=std::numeric_limits<double>::max();
93      const DataLookup1D a(matrix_,i,false);
94      for(u_int j=0; j<target_.size(); j++) {           
95        DataLookup1D b(matrix_,j,false);
96        double dist=distance_(a.begin, a.end(), b.begin());
97        if(j!=i && dist<mindist) {
98          mindist=dist;
99          neighbor=j;
100        }
101      }
102      if(target_(i)==target_(neighbor))
103        igp_(target_(i))++;
104     
105    }
106    for(u_int i=0; i<target_.nof_classes(); i++) {
107      igp_(i)/=static_cast<double>(target_.size(i));
108    }
109  }
110 
111  template <typename Distance>
112  IGP<Distance>::~IGP()   
113  {
114  }
115
116 
117  template <typename Distance>
118  const utility::Vector& IGP<Distance>::score(void) const 
119  {
120    return igp_;
121  }
122 
123}}} // of namespace classifier, yat, and theplu
124
125#endif
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