1 | #ifndef _theplu_yat_classifier_igp_ |
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2 | #define _theplu_yat_classifier_igp_ |
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3 | |
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4 | // $Id$ |
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5 | |
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6 | /* |
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7 | Copyright (C) 2006 Jari Häkkinen, Markus Ringnér |
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8 | Copyright (C) 2007, 2008 Jari Häkkinen, Peter Johansson, Markus Ringnér |
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9 | Copyright (C) 2009 Peter Johansson |
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10 | |
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11 | This file is part of the yat library, http://dev.thep.lu.se/yat |
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12 | |
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13 | The yat library is free software; you can redistribute it and/or |
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14 | modify it under the terms of the GNU General Public License as |
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15 | published by the Free Software Foundation; either version 3 of the |
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16 | License, or (at your option) any later version. |
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17 | |
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18 | The yat library is distributed in the hope that it will be useful, |
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19 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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20 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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21 | General Public License for more details. |
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22 | |
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23 | You should have received a copy of the GNU General Public License |
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24 | along with yat. If not, see <http://www.gnu.org/licenses/>. |
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25 | */ |
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26 | |
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27 | #include "MatrixLookup.h" |
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28 | #include "Target.h" |
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29 | #include "yat/utility/Vector.h" |
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30 | #include "yat/utility/yat_assert.h" |
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31 | |
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32 | #include <cmath> |
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33 | #include <limits> |
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34 | #include <stdexcept> |
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35 | |
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36 | namespace theplu { |
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37 | namespace yat { |
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38 | namespace classifier { |
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39 | |
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40 | class Target; |
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41 | class MatrixLookup; |
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42 | |
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43 | /// |
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44 | /// @brief Class for In Group Proportions (IGP) |
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45 | /// |
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46 | /// See <a HREF="http://biostatistics.oxfordjournals.org/cgi/content/abstract/kxj029v1">Kapp and Tibshirani, Biostatistics (2006)</a>. |
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47 | /// |
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48 | template <typename Distance> |
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49 | class IGP |
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50 | { |
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51 | |
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52 | public: |
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53 | /// |
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54 | /// Constructor taking the training data and the target vector and |
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55 | /// as input. |
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56 | /// |
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57 | IGP(const MatrixLookup&, const Target&); |
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58 | |
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59 | |
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60 | /// |
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61 | /// Constructor taking the training data, the target vector and |
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62 | /// the distance measure as input. |
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63 | /// |
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64 | IGP(const MatrixLookup&, const Target&, const Distance&); |
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65 | |
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66 | /// |
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67 | /// Destrucutor |
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68 | /// |
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69 | virtual ~IGP(); |
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70 | |
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71 | /// |
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72 | /// @return the IGP score for each class as elements in a vector. |
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73 | /// |
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74 | const utility::Vector& score(void) const; |
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75 | |
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76 | |
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77 | private: |
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78 | void calculate(); |
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79 | |
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80 | utility::Vector igp_; |
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81 | Distance distance_; |
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82 | |
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83 | const MatrixLookup& matrix_; |
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84 | const Target& target_; |
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85 | }; |
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86 | |
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87 | |
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88 | // templates |
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89 | |
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90 | template <typename Distance> |
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91 | IGP<Distance>::IGP(const MatrixLookup& data, const Target& target) |
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92 | : matrix_(data), target_(target) |
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93 | { |
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94 | calculate(); |
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95 | } |
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96 | |
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97 | template <typename Distance> |
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98 | IGP<Distance>::IGP(const MatrixLookup& data, const Target& target, const Distance& dist) |
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99 | : matrix_(data), target_(target), distance_(dist) |
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100 | { |
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101 | calculate(); |
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102 | } |
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103 | |
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104 | |
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105 | template <typename Distance> |
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106 | IGP<Distance>::~IGP() |
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107 | { |
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108 | } |
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109 | |
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110 | template <typename Distance> |
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111 | void IGP<Distance>::calculate() |
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112 | { |
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113 | utility::yat_assert<std::runtime_error>(target_.size()==matrix_.columns()); |
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114 | |
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115 | // Calculate IGP for each class |
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116 | igp_ = utility::Vector(target_.nof_classes()); |
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117 | |
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118 | for(size_t i=0; i<target_.size(); i++) { |
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119 | size_t neighbor=i; |
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120 | double mindist=std::numeric_limits<double>::max(); |
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121 | for(size_t j=0; j<target_.size(); j++) { |
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122 | if (i==j) // avoid self-self comparison |
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123 | continue; |
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124 | double dist = distance_(matrix_.begin_column(i), matrix_.end_column(i), |
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125 | matrix_.begin_column(j)); |
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126 | if(dist<mindist) { |
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127 | mindist=dist; |
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128 | neighbor=j; |
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129 | } |
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130 | } |
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131 | if(target_(i)==target_(neighbor)) |
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132 | igp_(target_(i))++; |
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133 | |
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134 | } |
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135 | for(size_t i=0; i<target_.nof_classes(); i++) { |
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136 | igp_(i)/=static_cast<double>(target_.size(i)); |
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137 | } |
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138 | } |
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139 | |
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140 | |
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141 | template <typename Distance> |
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142 | const utility::Vector& IGP<Distance>::score(void) const |
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143 | { |
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144 | return igp_; |
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145 | } |
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146 | |
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147 | }}} // of namespace classifier, yat, and theplu |
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148 | |
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149 | #endif |
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