source: trunk/yat/statistics/ROCScore.cc @ 781

Last change on this file since 781 was 781, checked in by Peter, 15 years ago

changing name to ROCScore and also added some cassert includes

  • Property svn:eol-style set to native
  • Property svn:keywords set to Author Date Id Revision
File size: 3.1 KB
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1// $Id: ROCScore.cc 781 2007-03-05 19:44:03Z peter $
2
3/*
4  Copyright (C) The authors contributing to this file.
5
6  This file is part of the yat library, http://lev.thep.lu.se/trac/yat
7
8  The yat library is free software; you can redistribute it and/or
9  modify it under the terms of the GNU General Public License as
10  published by the Free Software Foundation; either version 2 of the
11  License, or (at your option) any later version.
12
13  The yat library is distributed in the hope that it will be useful,
14  but WITHOUT ANY WARRANTY; without even the implied warranty of
15  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  General Public License for more details.
17
18  You should have received a copy of the GNU General Public License
19  along with this program; if not, write to the Free Software
20  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
21  02111-1307, USA.
22*/
23
24#include "ROCScore.h"
25#include "yat/classifier/DataLookupWeighted1D.h"
26#include "yat/classifier/Target.h"
27#include "yat/utility/stl_utility.h"
28#include "yat/utility/vector.h"
29
30#include <cassert>
31#include <cmath>
32#include <utility>
33#include <map>
34
35namespace theplu {
36namespace yat {
37namespace statistics { 
38
39  ROCScore::ROCScore(bool absolute)
40    : Score(absolute)
41  {
42  }
43
44  double ROCScore::score(const classifier::Target& target, 
45                         const utility::vector& value) const
46  {
47    assert(target.size()==value.size());
48    // key data, pair<target, weight>
49    std::multimap<double, std::pair<bool, double> > m;
50    for (unsigned int i=0; i<target.size(); i++)
51      m.insert(std::make_pair(value(i), 
52                              std::make_pair(target.binary(i),1.0)));
53       
54    return score(m);
55  }
56
57
58
59  double ROCScore::score(const classifier::Target& target, 
60                         const classifier::DataLookupWeighted1D& value) const
61  {
62    assert(target.size()==value.size());
63    // key data, pair<target, weight>
64    std::multimap<double, std::pair<bool, double> > m;
65    for (unsigned int i=0; i<target.size(); i++)
66      if (value.weight(i))
67        m.insert(std::make_pair(value.data(i), 
68                                std::make_pair(target.binary(i), 
69                                               value.weight(i))));
70       
71    return score(m);
72  }
73
74
75  double ROCScore::score(const classifier::Target& target, 
76                         const utility::vector& value, 
77                         const utility::vector& weight) const
78  {
79    assert(target.size()==value.size());
80    assert(target.size()==weight.size());
81    // key data, pair<target, weight>
82    std::multimap<double, std::pair<bool, double> > m;
83    for (unsigned int i=0; i<target.size(); i++)
84      if (weight(i))
85        m.insert(std::make_pair(value(i), 
86                                std::make_pair(target.binary(i), weight(i))));
87       
88    return score(m);
89  }
90
91
92  double 
93  ROCScore::score(const MultiMap& m) const
94  {
95    double area=0;
96    double cumsum_pos_w=0;
97    double cumsum_neg_w=0;
98    typedef MultiMap::const_iterator iter;
99
100    for (iter i=m.begin(); i!=m.end(); ++i)
101      if (i->second.first){
102        area += i->second.second * cumsum_neg_w;
103        cumsum_pos_w += i->second.second;
104      }
105      else
106        cumsum_neg_w += i->second.second;
107
108    // max area is cumsum_neg_w * cumsum_pos_w
109    area/=(cumsum_neg_w*cumsum_pos_w);
110   
111    if (area<0.5 && absolute_)
112      return 1.0-area;
113    return area;
114}
115
116}}} // of namespace statistics, yat, and theplu
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