multi-ngram.1

这是一款很好用的工具包

multi-ngram(1)                                     multi-ngram(1)



NNAAMMEE
       multi-ngram - build multiword N-gram models

SSYYNNOOPPSSIISS
       mmuullttii--nnggrraamm [--hheellpp] option ...

DDEESSCCRRIIPPTTIIOONN
       mmuullttii--nnggrraamm  builds  N-gram  language  models that contain
       multiwords, i.e., compound words that are a  concatenation
       of  words from some prior given model.  It will optionally
       generate multiword N-grams and insert them into an  exist-
       ing,  reference  N-gram  model,  so as to cover multiwords
       occuring in a specified vocabulary.  It will  then  assign
       probabilities  to  the  multiword  N-grams  so  that  word
       strings containing multiwords have the same  probabilities
       as  the strings of component words in the reference model.

       Note that the inverse operation (expanding a multiword  N-
       gram  to  contain  only  regular words) is subsumed by the
       nnggrraamm --eexxppaanndd--ccllaasssseess function.

OOPPTTIIOONNSS
       Each filename argument can be an ASCII  file,  or  a  com-
       pressed file (name ending in .Z or .gz), or ``-'' to indi-
       cate stdin/stdout.

       --hheellpp  Print option summary.

       --vveerrssiioonn
              Print version information.

       --oorrddeerr _n
              Set the maximal N-gram order to be  used  from  the
              reference  model.   NOTE: The order of the model is
              not set automatically when a model file is read, so
              the  same  file  can be used at various orders.  To
              use models of order higher than 3 it is always nec-
              essary to specify this option.

       --mmuullttii--oorrddeerr _n
              The  maximal  N-gram  order  in the multiword-based
              model.

       --ddeebbuugg _l_e_v_e_l
              Set the debugging output level (0 means  no  debug-
              ging output).

       --vvooccaabb _f_i_l_e
              Words  to  be  added  to the model.  In particular,
              this should include all the multiwords to be added.

       --mmuullttii--cchhaarr _C
              Character used to delimit component words in multi-
              words (an underscore character by default).

       --llmm _f_i_l_e
              Reference N-gram model.

       --mmuullttii--llmm _f_i_l_e
              Model containing multiwords; the  N-grams  in  this
              model  will  be assigned new probabilities based on
              the reference model.  If this option is  _n_o_t  given
              then  the  multiword  model  will  be  generated by
              adding multiword N-grams to the reference model.

       --pprruunnee--uunnsseeeenn--nnggrraammss
              This option prevents the insertion of multiword  N-
              grams  whose component N-grams are not contained in
              the reference model.  For example, for a  multiword
              bigram  "a_b  c_d" to be inserted, a trigram refer-
              ence model must contain the trigrams "a b c" and "b
              c  d".  If the reference model were a bigram LM, it
              would have to contain "a b",  "b  c",  and  "c  d".
              This option is important to control the size of the
              multiword LM for large vocabularies.

       --wwrriittee--llmm _f_i_l_e
              Output location of the generated multiword model.

SSEEEE AALLSSOO
       ngram(1), ngram-format(5).

BBUUGGSS
       This program is a hack for cases were the original  train-
       ing  data is not available and a multiword model has to be
       generated from an existing model.
       The resulting model  is  no  longer  properly  normalized,
       since  the same word string can potentially be represented
       with or without multiwords.
       The generation of multiword N-grams uses a heuristic algo-
       rithm that works well for bigrams and trigrams, but is not
       exhaustive.

AAUUTTHHOORR
       Andreas Stolcke <[e-mail]>.
       Copyright 2000-2004 SRI International



SRILM Tools        $Date: 2004/12/03 17:59:01 $    multi-ngram(1)