This class can be used to convert a document collection contained in a CStringFeatures<char> object where each document is stored as a single vector into a hashed Bag-of-Words representation. Like in the standard Bag-of-Words representation, this class considers each document as a collection of tokens, which are then hashed into a new feature space of a specified dimension. This class is very flexible and allows the user to specify the tokenizer used to tokenize each document, specify whether the results should be normalized with regards to the sqrt of the document size, as well as to specify whether he wants to combine different tokens. The latter implements a k-skip n-grams approach, meaning that you can combine up to n tokens, while skipping up to k. Eg. for the tokens ["a", "b", "c", "d"], with n_grams = 2 and skips = 2, one would get the following combinations : ["a", "ab", "ac" (skipped 1), "ad" (skipped 2), "b", "bc", "bd" (skipped 1), "c", "cd", "d"].
在文件 HashedDocConverter.h 第 39 行定义.
Public 成员函数 | |
CHashedDocConverter () | |
CHashedDocConverter (int32_t hash_bits, bool normalize=false, int32_t n_grams=1, int32_t skips=0) | |
CHashedDocConverter (CTokenizer *tzer, int32_t hash_bits, bool normalize=false, int32_t n_grams=1, int32_t skips=0) | |
virtual | ~CHashedDocConverter () |
virtual CFeatures * | apply (CFeatures *features) |
SGSparseVector< float64_t > | apply (SGVector< char > document) |
virtual const char * | get_name () const |
void | set_normalization (bool normalize) |
void | set_k_skip_n_grams (int32_t k, int32_t n) |
virtual CSGObject * | shallow_copy () const |
virtual CSGObject * | deep_copy () const |
virtual bool | is_generic (EPrimitiveType *generic) const |
template<class T > | |
void | set_generic () |
template<> | |
void | set_generic () |
template<> | |
void | set_generic () |
template<> | |
void | set_generic () |
template<> | |
void | set_generic () |
template<> | |
void | set_generic () |
template<> | |
void | set_generic () |
template<> | |
void | set_generic () |
template<> | |
void | set_generic () |
template<> | |
void | set_generic () |
template<> | |
void | set_generic () |
template<> | |
void | set_generic () |
template<> | |
void | set_generic () |
template<> | |
void | set_generic () |
template<> | |
void | set_generic () |
template<> | |
void | set_generic () |
void | unset_generic () |
virtual void | print_serializable (const char *prefix="") |
virtual bool | save_serializable (CSerializableFile *file, const char *prefix="", int32_t param_version=Version::get_version_parameter()) |
virtual bool | load_serializable (CSerializableFile *file, const char *prefix="", int32_t param_version=Version::get_version_parameter()) |
DynArray< TParameter * > * | load_file_parameters (const SGParamInfo *param_info, int32_t file_version, CSerializableFile *file, const char *prefix="") |
DynArray< TParameter * > * | load_all_file_parameters (int32_t file_version, int32_t current_version, CSerializableFile *file, const char *prefix="") |
void | map_parameters (DynArray< TParameter * > *param_base, int32_t &base_version, DynArray< const SGParamInfo * > *target_param_infos) |
void | set_global_io (SGIO *io) |
SGIO * | get_global_io () |
void | set_global_parallel (Parallel *parallel) |
Parallel * | get_global_parallel () |
void | set_global_version (Version *version) |
Version * | get_global_version () |
SGStringList< char > | get_modelsel_names () |
void | print_modsel_params () |
char * | get_modsel_param_descr (const char *param_name) |
index_t | get_modsel_param_index (const char *param_name) |
void | build_gradient_parameter_dictionary (CMap< TParameter *, CSGObject * > *dict) |
virtual void | update_parameter_hash () |
virtual bool | parameter_hash_changed () |
virtual bool | equals (CSGObject *other, float64_t accuracy=0.0, bool tolerant=false) |
virtual CSGObject * | clone () |
静态 Public 成员函数 | |
static index_t | generate_ngram_hashes (SGVector< uint32_t > &hashes, index_t hashes_start, index_t len, SGVector< index_t > &ngram_hashes, int32_t num_bits, int32_t ngrams, int32_t tokens_to_skip) |
Public 属性 | |
SGIO * | io |
Parallel * | parallel |
Version * | version |
Parameter * | m_parameters |
Parameter * | m_model_selection_parameters |
Parameter * | m_gradient_parameters |
ParameterMap * | m_parameter_map |
uint32_t | m_hash |
Protected 成员函数 | |
void | init (CTokenizer *tzer, int32_t d, bool normalize, int32_t n_grams, int32_t skips) |
int32_t | count_distinct_indices (CDynamicArray< uint32_t > &hashed_indices) |
SGSparseVector< float64_t > | create_hashed_representation (CDynamicArray< uint32_t > &hashed_indices) |
virtual TParameter * | migrate (DynArray< TParameter * > *param_base, const SGParamInfo *target) |
virtual void | one_to_one_migration_prepare (DynArray< TParameter * > *param_base, const SGParamInfo *target, TParameter *&replacement, TParameter *&to_migrate, char *old_name=NULL) |
virtual void | load_serializable_pre () throw (ShogunException) |
virtual void | load_serializable_post () throw (ShogunException) |
virtual void | save_serializable_pre () throw (ShogunException) |
virtual void | save_serializable_post () throw (ShogunException) |
Protected 属性 | |
int32_t | num_bits |
CTokenizer * | tokenizer |
bool | should_normalize |
int32_t | ngrams |
int32_t | tokens_to_skip |
Default constructor
在文件 HashedDocConverter.cpp 第 23 行定义.
CHashedDocConverter | ( | int32_t | hash_bits, |
bool | normalize = false , |
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int32_t | n_grams = 1 , |
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int32_t | skips = 0 |
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Constructor Creates tokens on whitespace
hash_bits | the number of bits of the hash. Means a dimension of size 2^(hash_bits). |
normalize | whether to normalize vectors or not |
n_grams | the max number of tokens to consider when combining tokens |
skips | the max number of tokens to skip when combining tokens |
在文件 HashedDocConverter.cpp 第 28 行定义.
CHashedDocConverter | ( | CTokenizer * | tzer, |
int32_t | hash_bits, | ||
bool | normalize = false , |
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int32_t | n_grams = 1 , |
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int32_t | skips = 0 |
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) |
Constructor
tzer | the tokenizer to use |
hash_bits | the number of bits of the hash. Means a dimension of size 2^(hash_bits). |
normalize | whether to normalize vectors or not |
n_grams | the max number of tokens to consider when combining tokens |
skips | the max number of tokens to skip when combining tokens |
在文件 HashedDocConverter.cpp 第 34 行定义.
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virtual |
Destructor
在文件 HashedDocConverter.cpp 第 40 行定义.
Hashes each string contained in features
features | the strings to be hashed. Must be an instance of CStringFeatures. |
实现了 CConverter.
在文件 HashedDocConverter.cpp 第 81 行定义.
SGSparseVector< float64_t > apply | ( | SGVector< char > | document | ) |
Hashes the tokens contained in document
document | the char vector to tokenize and hash |
the array will contain all the hashes generated from the tokens
this vector will maintain the current n+k active tokens in a circular manner
the combinations generated from the current active tokens will be stored here to avoid creating new objects
Reading n+s-1 tokens
Reading token and storing index to hashed_indices
For remaining combinations
Normalizing vector
在文件 HashedDocConverter.cpp 第 101 行定义.
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inherited |
Builds a dictionary of all parameters in SGObject as well of those of SGObjects that are parameters of this object. Dictionary maps parameters to the objects that own them.
dict | dictionary of parameters to be built. |
在文件 SGObject.cpp 第 1185 行定义.
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virtualinherited |
Creates a clone of the current object. This is done via recursively traversing all parameters, which corresponds to a deep copy. Calling equals on the cloned object always returns true although none of the memory of both objects overlaps.
在文件 SGObject.cpp 第 1302 行定义.
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protected |
This method takes a dynamic array as an argument, sorts it and returns the number of the distinct elements(indices here) in the array.
hashed_indices | the array to sort and count elements |
Counting nnz features
在文件 HashedDocConverter.cpp 第 228 行定义.
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protected |
This method takes the dynamic array containing all the hashed indices of a document and returns a compact sparse representation with each index found and with the count of such index
hashed_indices | the array containing the hashed indices |
在文件 HashedDocConverter.cpp 第 184 行定义.
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virtualinherited |
A deep copy. All the instance variables will also be copied.
在文件 SGObject.cpp 第 146 行定义.
Recursively compares the current SGObject to another one. Compares all registered numerical parameters, recursion upon complex (SGObject) parameters. Does not compare pointers!
May be overwritten but please do with care! Should not be necessary in most cases.
other | object to compare with |
accuracy | accuracy to use for comparison (optional) |
tolerant | allows linient check on float equality (within accuracy) |
在文件 SGObject.cpp 第 1206 行定义.
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static |
Generates all the k-skip n-grams combinations for the pre-hashed tokens in hashes, starting from hashes[hashes_start] and going up to hashes[1+len] in a circular manner. The generated tokens (maximun (n-1)(k+1)+1) are stored in ngram_hashes. The number of created tokens is returned in case fewer tokens are generated (due to a smaller len than the size of hashes). See class description for more information on k-skip n-grams.
hashes | the hashes of the tokens to combine as k-skip n-grams |
hashes_start | the index in hashes to consider as the starting point |
len | the maximum allowed number of tokens to reach in a circular manner, starting from hashes_start |
ngram_hashes | the vector where to store the generated hashes. Must have been created to be able to store at most (n-1)(k+1)+1 tokens. |
num_bits | the dimension in which to limit the hashed indices (means a dimension of size 2^num_bits) |
ngrams | the n in k-skip n-grams or the max number of tokens to combine |
tokens_to_skip | the k in k-skip n-grams or the max number of tokens to skip when combining |
在文件 HashedDocConverter.cpp 第 205 行定义.
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inherited |
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inherited |
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inherited |
在文件 SGObject.cpp 第 1077 行定义.
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inherited |
Returns description of a given parameter string, if it exists. SG_ERROR otherwise
param_name | name of the parameter |
在文件 SGObject.cpp 第 1101 行定义.
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inherited |
Returns index of model selection parameter with provided index
param_name | name of model selection parameter |
在文件 SGObject.cpp 第 1114 行定义.
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init
在文件 HashedDocConverter.cpp 第 45 行定义.
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virtualinherited |
If the SGSerializable is a class template then TRUE will be returned and GENERIC is set to the type of the generic.
generic | set to the type of the generic if returning TRUE |
在文件 SGObject.cpp 第 243 行定义.
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inherited |
maps all parameters of this instance to the provided file version and loads all parameter data from the file into an array, which is sorted (basically calls load_file_parameter(...) for all parameters and puts all results into a sorted array)
file_version | parameter version of the file |
current_version | version from which mapping begins (you want to use Version::get_version_parameter() for this in most cases) |
file | file to load from |
prefix | prefix for members |
在文件 SGObject.cpp 第 648 行定义.
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inherited |
loads some specified parameters from a file with a specified version The provided parameter info has a version which is recursively mapped until the file parameter version is reached. Note that there may be possibly multiple parameters in the mapping, therefore, a set of TParameter instances is returned
param_info | information of parameter |
file_version | parameter version of the file, must be <= provided parameter version |
file | file to load from |
prefix | prefix for members |
在文件 SGObject.cpp 第 489 行定义.
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virtualinherited |
Load this object from file. If it will fail (returning FALSE) then this object will contain inconsistent data and should not be used!
file | where to load from |
prefix | prefix for members |
param_version | (optional) a parameter version different to (this is mainly for testing, better do not use) |
在文件 SGObject.cpp 第 320 行定义.
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protectedvirtualinherited |
Can (optionally) be overridden to post-initialize some member variables which are not PARAMETER::ADD'ed. Make sure that at first the overridden method BASE_CLASS::LOAD_SERIALIZABLE_POST is called.
ShogunException | Will be thrown if an error occurres. |
被 CKernel, CWeightedDegreePositionStringKernel, CList, CAlphabet, CLinearHMM, CGaussianKernel, CInverseMultiQuadricKernel, CCircularKernel , 以及 CExponentialKernel 重载.
在文件 SGObject.cpp 第 1004 行定义.
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protectedvirtualinherited |
Can (optionally) be overridden to pre-initialize some member variables which are not PARAMETER::ADD'ed. Make sure that at first the overridden method BASE_CLASS::LOAD_SERIALIZABLE_PRE is called.
ShogunException | Will be thrown if an error occurres. |
被 CDynamicArray< T >, CDynamicArray< float64_t >, CDynamicArray< float32_t >, CDynamicArray< int32_t >, CDynamicArray< char >, CDynamicArray< bool > , 以及 CDynamicObjectArray 重载.
在文件 SGObject.cpp 第 999 行定义.
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inherited |
Takes a set of TParameter instances (base) with a certain version and a set of target parameter infos and recursively maps the base level wise to the current version using CSGObject::migrate(...). The base is replaced. After this call, the base version containing parameters should be of same version/type as the initial target parameter infos. Note for this to work, the migrate methods and all the internal parameter mappings have to match
param_base | set of TParameter instances that are mapped to the provided target parameter infos |
base_version | version of the parameter base |
target_param_infos | set of SGParamInfo instances that specify the target parameter base |
在文件 SGObject.cpp 第 686 行定义.
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protectedvirtualinherited |
creates a new TParameter instance, which contains migrated data from the version that is provided. The provided parameter data base is used for migration, this base is a collection of all parameter data of the previous version. Migration is done FROM the data in param_base TO the provided param info Migration is always one version step. Method has to be implemented in subclasses, if no match is found, base method has to be called.
If there is an element in the param_base which equals the target, a copy of the element is returned. This represents the case when nothing has changed and therefore, the migrate method is not overloaded in a subclass
param_base | set of TParameter instances to use for migration |
target | parameter info for the resulting TParameter |
在文件 SGObject.cpp 第 893 行定义.
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protectedvirtualinherited |
This method prepares everything for a one-to-one parameter migration. One to one here means that only ONE element of the parameter base is needed for the migration (the one with the same name as the target). Data is allocated for the target (in the type as provided in the target SGParamInfo), and a corresponding new TParameter instance is written to replacement. The to_migrate pointer points to the single needed TParameter instance needed for migration. If a name change happened, the old name may be specified by old_name. In addition, the m_delete_data flag of to_migrate is set to true. So if you want to migrate data, the only thing to do after this call is converting the data in the m_parameter fields. If unsure how to use - have a look into an example for this. (base_migration_type_conversion.cpp for example)
param_base | set of TParameter instances to use for migration |
target | parameter info for the resulting TParameter |
replacement | (used as output) here the TParameter instance which is returned by migration is created into |
to_migrate | the only source that is used for migration |
old_name | with this parameter, a name change may be specified |
在文件 SGObject.cpp 第 833 行定义.
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virtualinherited |
在文件 SGObject.cpp 第 209 行定义.
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inherited |
prints all parameter registered for model selection and their type
在文件 SGObject.cpp 第 1053 行定义.
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virtualinherited |
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virtualinherited |
Save this object to file.
file | where to save the object; will be closed during returning if PREFIX is an empty string. |
prefix | prefix for members |
param_version | (optional) a parameter version different to (this is mainly for testing, better do not use) |
在文件 SGObject.cpp 第 261 行定义.
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protectedvirtualinherited |
Can (optionally) be overridden to post-initialize some member variables which are not PARAMETER::ADD'ed. Make sure that at first the overridden method BASE_CLASS::SAVE_SERIALIZABLE_POST is called.
ShogunException | Will be thrown if an error occurres. |
被 CKernel 重载.
在文件 SGObject.cpp 第 1014 行定义.
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protectedvirtualinherited |
Can (optionally) be overridden to pre-initialize some member variables which are not PARAMETER::ADD'ed. Make sure that at first the overridden method BASE_CLASS::SAVE_SERIALIZABLE_PRE is called.
ShogunException | Will be thrown if an error occurres. |
被 CKernel, CDynamicArray< T >, CDynamicArray< float64_t >, CDynamicArray< float32_t >, CDynamicArray< int32_t >, CDynamicArray< char >, CDynamicArray< bool > , 以及 CDynamicObjectArray 重载.
在文件 SGObject.cpp 第 1009 行定义.
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在文件 SGObject.cpp 第 38 行定义.
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在文件 SGObject.cpp 第 43 行定义.
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在文件 SGObject.cpp 第 48 行定义.
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在文件 SGObject.cpp 第 53 行定义.
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在文件 SGObject.cpp 第 58 行定义.
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在文件 SGObject.cpp 第 63 行定义.
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在文件 SGObject.cpp 第 68 行定义.
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在文件 SGObject.cpp 第 73 行定义.
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在文件 SGObject.cpp 第 78 行定义.
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在文件 SGObject.cpp 第 83 行定义.
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在文件 SGObject.cpp 第 88 行定义.
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在文件 SGObject.cpp 第 93 行定义.
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在文件 SGObject.cpp 第 98 行定义.
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在文件 SGObject.cpp 第 103 行定义.
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在文件 SGObject.cpp 第 108 行定义.
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set generic type to T
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void set_k_skip_n_grams | ( | int32_t | k, |
int32_t | n | ||
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Method used to specify the parameters for the quadratic approach of k-skip n-grams. See class description for more details and an example.
k | the max number of allowed skips |
n | the max number of tokens to combine |
在文件 HashedDocConverter.cpp 第 251 行定义.
void set_normalization | ( | bool | normalize | ) |
specify whether hashed vector should be normalized or not
normalize | whether to normalize |
在文件 HashedDocConverter.cpp 第 246 行定义.
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virtualinherited |
A shallow copy. All the SGObject instance variables will be simply assigned and SG_REF-ed.
被 CGaussianKernel 重载.
在文件 SGObject.cpp 第 140 行定义.
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unset generic type
this has to be called in classes specializing a template class
在文件 SGObject.cpp 第 250 行定义.
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Updates the hash of current parameter combination
在文件 SGObject.cpp 第 196 行定义.
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io
在文件 SGObject.h 第 461 行定义.
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parameters wrt which we can compute gradients
在文件 SGObject.h 第 476 行定义.
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Hash of parameter values
在文件 SGObject.h 第 482 行定义.
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model selection parameters
在文件 SGObject.h 第 473 行定义.
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map for different parameter versions
在文件 SGObject.h 第 479 行定义.
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parameters
在文件 SGObject.h 第 470 行定义.
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the number of consecutives tokens for quadratic
在文件 HashedDocConverter.h 第 154 行定义.
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the number of bits of the hash
在文件 HashedDocConverter.h 第 145 行定义.
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parallel
在文件 SGObject.h 第 464 行定义.
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whether to normalize or not
在文件 HashedDocConverter.h 第 151 行定义.
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the tokenizer
在文件 HashedDocConverter.h 第 148 行定义.
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the number of tokens to skip
在文件 HashedDocConverter.h 第 157 行定义.
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version
在文件 SGObject.h 第 467 行定义.