Go to the documentation of this file.00001
00002
00003
00004
00005
00006
00007
00008
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___