SHOGUN v0.9.0
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00001 /* 00002 * This program is free software; you can redistribute it and/or modify 00003 * it under the terms of the GNU General Public License as published by 00004 * the Free Software Foundation; either version 3 of the License, or 00005 * (at your option) any later version. 00006 * 00007 * Written (W) 2010 Soeren Sonnenburg 00008 * Copyright (C) 2010 Berlin Institute of Technology 00009 */ 00010 00011 #ifndef _HASHEDWDFEATURES_H___ 00012 #define _HASHEDWDFEATURES_H___ 00013 00014 #include "lib/common.h" 00015 #include "features/DotFeatures.h" 00016 #include "features/StringFeatures.h" 00017 #include "lib/Hash.h" 00018 00019 namespace shogun 00020 { 00021 template <class ST> class CStringFeatures; 00022 00028 class CHashedWDFeatures : public CDotFeatures 00029 { 00030 public: 00032 CHashedWDFeatures(void); 00033 00042 CHashedWDFeatures(CStringFeatures<uint8_t>* str, int32_t start_order, 00043 int32_t order, int32_t from_order, int32_t hash_bits=12); 00044 00046 CHashedWDFeatures(const CHashedWDFeatures & orig); 00047 00049 virtual ~CHashedWDFeatures(); 00050 00058 inline virtual int32_t get_dim_feature_space() 00059 { 00060 return w_dim; 00061 } 00062 00070 virtual float64_t dot(int32_t vec_idx1, CDotFeatures* df, int32_t vec_idx2); 00071 00078 virtual float64_t dense_dot(int32_t vec_idx1, const float64_t* vec2, int32_t vec2_len); 00079 00088 virtual void add_to_dense_vec(float64_t alpha, int32_t vec_idx1, float64_t* vec2, int32_t vec2_len, bool abs_val=false); 00089 00095 virtual inline int32_t get_nnz_features_for_vector(int32_t num) 00096 { 00097 int32_t vlen=-1; 00098 bool free_vec; 00099 uint8_t* vec=strings->get_feature_vector(num, vlen, free_vec); 00100 strings->free_feature_vector(vec, num, free_vec); 00101 return degree*vlen; 00102 } 00103 00105 struct hashed_wd_feature_iterator 00106 { 00108 uint16_t* vec; 00110 int32_t vidx; 00112 int32_t vlen; 00114 bool vfree; 00115 00117 int32_t index; 00118 00119 }; 00120 00130 virtual void* get_feature_iterator(int32_t vector_index) 00131 { 00132 SG_NOTIMPLEMENTED; 00133 return NULL; 00134 } 00135 00146 virtual bool get_next_feature(int32_t& index, float64_t& value, void* iterator) 00147 { 00148 SG_NOTIMPLEMENTED; 00149 return NULL; 00150 } 00151 00157 virtual void free_feature_iterator(void* iterator) 00158 { 00159 SG_NOTIMPLEMENTED; 00160 } 00161 00166 virtual CFeatures* duplicate() const; 00167 00172 inline virtual EFeatureType get_feature_type() 00173 { 00174 return F_UNKNOWN; 00175 } 00176 00181 inline virtual EFeatureClass get_feature_class() 00182 { 00183 return C_WD; 00184 } 00185 00186 inline virtual int32_t get_num_vectors() 00187 { 00188 return num_strings; 00189 } 00190 00191 inline virtual int32_t get_size() 00192 { 00193 return sizeof(float64_t); 00194 } 00195 00198 void set_normalization_const(float64_t n=0); 00199 00201 inline float64_t get_normalization_const() 00202 { 00203 return normalization_const; 00204 } 00205 00207 inline virtual const char* get_name() const { return "HashedWDFeatures"; } 00208 00209 protected: 00210 00212 void set_wd_weights(); 00213 00214 protected: 00216 CStringFeatures<uint8_t>* strings; 00217 00219 int32_t degree; 00221 int32_t start_degree; 00223 int32_t from_degree; 00225 int32_t string_length; 00227 int32_t num_strings; 00229 int32_t alphabet_size; 00231 int32_t w_dim; 00233 int32_t partial_w_dim; 00235 float64_t* wd_weights; 00237 uint32_t mask; 00239 int32_t m_hash_bits; 00240 00242 float64_t normalization_const; 00243 }; 00244 } 00245 #endif // _HASHEDWDFEATURES_H___