NGRAM_INFO Struct Reference

Main N-gram structure. More...

#include <ngram2.h>

Collaboration diagram for NGRAM_INFO:

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Data Fields
int	version
	version number
boolean	from_bin
	TRUE if source is bingram, otherwise ARPA.
WORD_ID	max_word_num
	N-gram vocabulary size.
NNID	ngram_num [MAX_N]
	Total number of tuples for each N.
NNID	bigram_bo_num
	Total number of bigram tuples that has back-off weight (i.e. context of upper 3-gram) (v4).
WORD_ID	unk_id
	Unknown word ID.
int	unk_num
	Number of dictionary words that are not in this N-gram vocabulary.
LOGPROB	unk_num_log
	Log10 value of unk_num, used for calculating probability of unknown words.
boolean	isopen
	TRUE if dictionary has unknown words, which does not appear in this N-gram.
char **	wname
	List of word string [nid].
PATNODE *	root
	Root of index tree to search n-gram word ID from its name.
LOGPROB *	p
	1-gram log probabilities [nid]
LOGPROB *	bo_wt_lr
	Back-off weights for LR 2-gram [nid].
LOGPROB *	bo_wt_rl
	Back-off weights for RL 2-gram [nid].
NNID *	n2_bgn
	2-gram IDs (n2) representing beginning point of 2-gram entries that have the left context
WORD_ID *	n2_num
	Number of 2-gram that have the left context of above.
WORD_ID *	n2tonid
	Mapping each 2-gram index ID (n2) to its last word ID (nid).
LOGPROB *	p_lr
	LR 2-gram log probabilities [n2].
LOGPROB *	p_rl
	RL 2-gram log probabilities [n2].
NNID_UPPER *	n2bo_upper
	Mapping each 2-gram index ID (n2) to bigram back-off index (n2-bo) (v4).
NNID_LOWER *	n2bo_lower
	Mapping each 2-gram index ID (n2) to bigram back-off index (n2-bo) (v4).
LOGPROB *	bo_wt_rrl
	Back-off weights for RL 3-gram [n2-bo].
NNID *	n3_bgn
	3-gram IDs (n3) representing beginning point of 3-gram entries that have the left context (v3)
NNID_UPPER *	n3_bgn_upper
	upper 8-bit 3-gram IDs (n3) representing beginning point of 3-gram entries that have the left context (v4)
NNID_LOWER *	n3_bgn_lower
	lower 16-bit 3-gram IDs (n3) representing beginning point of 3-gram entries that have the left context (v4)
WORD_ID *	n3_num
	Number of 3-gram that have the left context of above.
WORD_ID *	n3tonid
	Mapping each 3-gram index ID (n3) to its last word ID (nid).
LOGPROB *	p_rrl
	RL 3-gram log probabilities [n3].

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Detailed Description

Main N-gram structure.

bigrams and trigrams are stored in the form of sequential lists. They are grouped by the same context, and referred from the context ((N-1)-gram) data by the beginning ID and its number.

Definition at line 113 of file ngram2.h.

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Field Documentation

WORD_ID NGRAM_INFO::unk_id

Unknown word ID. This value is always fixed to 0, since the CMU-Cambridge SLM Toolkit always define the unknown word "<UNK>" at the first word in vocabulary. See also: set_unknown_id Definition at line 126 of file ngram2.h. Referenced by bi_prob_lr(), bi_prob_rl(), make_ngram_ref(), make_voca_ref(), print_ngram_info(), set_unknown_id(), and tri_prob_rl().

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The documentation for this struct was generated from the following file:

• libsent/include/sent/ngram2.h

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