PLearn 0.1
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00001 // -*- C++ -*- 00002 00003 // NGramDistribution.h 00004 // 00005 // Copyright (C) 2004 Hugo Larochelle 00006 // 00007 // Redistribution and use in source and binary forms, with or without 00008 // modification, are permitted provided that the following conditions are met: 00009 // 00010 // 1. Redistributions of source code must retain the above copyright 00011 // notice, this list of conditions and the following disclaimer. 00012 // 00013 // 2. Redistributions in binary form must reproduce the above copyright 00014 // notice, this list of conditions and the following disclaimer in the 00015 // documentation and/or other materials provided with the distribution. 00016 // 00017 // 3. The name of the authors may not be used to endorse or promote 00018 // products derived from this software without specific prior written 00019 // permission. 00020 // 00021 // THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR 00022 // IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 00023 // OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN 00024 // NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 00025 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 00026 // TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 00027 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 00028 // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 00029 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 00030 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 00031 // 00032 // This file is part of the PLearn library. For more information on the PLearn 00033 // library, go to the PLearn Web site at www.plearn.org 00034 00035 /* ******************************************************* 00036 * $Id: NGramDistribution.h 8173 2007-10-10 22:43:12Z larocheh $ 00037 ******************************************************* */ 00038 00039 // Authors: Hugo Larochelle 00040 00044 #ifndef NGramDistribution_INC 00045 #define NGramDistribution_INC 00046 00047 #define THIS_PRECISION 0.0000001 00048 #define EM_PRECISION 0.0001 00049 00050 #include <plearn_learners/distributions/PDistribution.h> 00051 #include <plearn_learners/distributions/NGramTree.h> 00052 #include <plearn/base/ms_hash_wrapper.h> 00053 00054 namespace PLearn { 00055 using namespace std; 00056 00058 class NGramDistribution: public PDistribution 00059 { 00060 00061 private: 00062 00063 typedef PDistribution inherited; 00064 00065 protected: 00066 00067 // ********************* 00068 // * protected options * 00069 // ********************* 00070 00071 int voc_size; 00072 00073 public: 00074 00075 // ************************ 00076 // * public build options * 00077 // ************************ 00078 00080 bool nan_replace; 00081 00083 int n; 00084 00086 real additive_constant; 00087 00089 real discount_constant; 00090 00092 string smoothing; 00093 00095 string lambda_estimation; 00096 00098 Vec lambdas; 00099 00101 PP<NGramTree> tree; 00102 00103 00104 // **************** 00105 // * Constructors * 00106 // **************** 00107 00109 NGramDistribution(); 00110 00111 // ************************* 00112 // * PDistribution methods * 00113 // ************************* 00114 00115 private: 00116 00118 void build_(); 00119 00121 void getNGrams(Vec row, TVec<int>& ngram) const; 00122 00123 protected: 00124 00126 static void declareOptions(OptionList& ol); 00127 00128 public: 00129 00130 // ************************ 00131 // **** Object methods **** 00132 // ************************ 00133 00135 virtual void build(); 00136 00138 virtual void makeDeepCopyFromShallowCopy(CopiesMap& copies); 00139 00140 // Declare other standard object methods. 00141 PLEARN_DECLARE_OBJECT(NGramDistribution); 00142 00143 // ******************************* 00144 // **** PDistribution methods **** 00145 // ******************************* 00146 00148 virtual real log_density(const Vec& x) const; 00149 00151 virtual real survival_fn(const Vec& y) const; 00152 00154 virtual real cdf(const Vec& y) const; 00155 00157 virtual void expectation(Vec& mu) const; 00158 00160 virtual void variance(Mat& cov) const; 00161 00163 virtual void generate(Vec& y) const; 00164 00166 virtual real density(const Vec& y) const; 00167 00168 // ************************** 00169 // **** PLearner methods **** 00170 // ************************** 00171 00174 virtual void forget(); 00175 00177 virtual void train(); 00178 00179 }; 00180 00181 // Declare a few other classes and functions related to this class. 00182 DECLARE_OBJECT_PTR(NGramDistribution); 00183 00184 } // end of namespace PLearn 00185 00186 #endif 00187 00188 00189 /* 00190 Local Variables: 00191 mode:c++ 00192 c-basic-offset:4 00193 c-file-style:"stroustrup" 00194 c-file-offsets:((innamespace . 0)(inline-open . 0)) 00195 indent-tabs-mode:nil 00196 fill-column:79 00197 End: 00198 */ 00199 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :