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.IX Title "SLMBUILD 1"
.TH SLMBUILD 1 2024-02-10 "perl v5.38.2" "User Contributed Perl Documentation"
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.SH NAME
slmbuild \- generate language model from idngram file
.SH SYNOPSIS
.IX Header "SYNOPSIS"
slmbuild [\fIoption\fR]... \fIidngram_file\fR...
.SH DESCRIPTION
.IX Header "DESCRIPTION"
\&\fBslmbuild\fR generates a back-off smoothing language model from a given idngram file. Generally, the \fIidngram_file\fR is created by \fBids2ngram\fR.
.SH "OPTIONS All the following options are mandatory."
.IX Header "OPTIONS All the following options are mandatory."
.IP "\fB\-n\fR,\fB\-\-NMax\fR \fIN\fR" 4
.IX Item "-n,--NMax N"
1 for unigram, 2 for bigram, 3 for trigram. Any number not in the range of 1..3 is not valid.
.IP "\fB\-o\fR, \fB\-\-out\fR \fIoutput-file\fR" 4
.IX Item "-o, --out output-file"
Specify the output xfilei name.
.IP "\fB\-l\fR, \fB\-\-log\fR" 4
.IX Item "-l, --log"
using \fI\-log(pr)\fR, use \fIpr\fR directly by default.
.IP "\fB\-w\fR, \fB\-\-wordcount\fR \fIN\fR" 4
.IX Item "-w, --wordcount N"
Lexican size, number of different words.
.IP "\fB\-b\fR, \fB\-\-brk\fR \fIid\fR..." 4
.IX Item "-b, --brk id..."
Set the ids which should be treated as breaker.
.IP "\fB\-e\fR, \fB\-\-e\fR \fIid\fR..." 4
.IX Item "-e, --e id..."
Set the ids which should not be put into LM.
.IP "\fB\-c\fR, \fB\-\-cut\fR \fIc\fR..." 4
.IX Item "-c, --cut c..."
k\-grams whose freq <= c[k] are dropped.
.IP "\fB\-d\fR, \fB\-\-discount\fR \fImethod\fR, \fIparam\fR..." 4
.IX Item "-d, --discount method, param..."
The k\-th \fB\-d\fR parm specifies the discount method
.Sp
For k\-gram, possibble values for method/param are:
.Sp
.Vb 7
\&      B<GT>,I<R>,I<dis>  : B<GT> discount for r E<lt>= I<R>, r is the freq of a ngram.
\&                  Linear discount for those r E<gt> I<R>, i.e. r\*(Aq=r*dis
\&                  0 E<lt>E<lt> dis E<lt> 1.0, for example 0.999 
\&      B<ABS>,[I<dis>] : Absolute discount r\*(Aq=r\-I<dis>. And I<dis> is optional
\&                  0 E<lt>E<lt> I<dis> E<lt> cut[k]+1.0, normally I<dis> E<lt> 1.0.
\&      LIN,[I<dis>] : Linear discount r\*(Aq=r*dis. And dis is optional
\&                  0 E<lt> dis E<lt> 1.0
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.SH NOTE
.IX Header "NOTE"
\&\fB\-n\fR must be given before \fB\-c\fR \fB\-b\fR. And \fB\-c\fR must give right number of cut-off,
also \fB\-d\fRs must appear exactly N times specifying the discounts for 1\-gram, 2\-gram..., 
respectively.
.PP
BREAKER-IDs could be SentenceTokens or ParagraphTokens. Conceptually,
these ids have no meaning when they appeared in the middle of n\-gram.
.PP
EXCLUDE-IDs could be ambiguious-ids. Conceptually, n\-grams which
contain those ids are meaningless.
.PP
We can not erase ngrams according to BREAKER-IDS and EXCLUDE-IDs directly
from IDNGRAM file, because some low-level information is still useful in it.
.SH EXAMPLE
.IX Header "EXAMPLE"
Following example read 'all.id3gram' and write trigram model 'all.slm'.
.PP
At 1\-gram level, use Good-Turing discount with cut-off 0, i<R>=8, \fIdis\fR=0.9995. At
2\-gram level, use Absolute discount with cut-off 3, dis auto-calc. At 3\-gram
level, use Absolute discount with cut-off 2, dis auto-calc. Word id 10,11,12
are breakers (sentence/para/paper breaker, etc). Exclude-ID is 9. Lexicon 
contains 200000 words. The result languagme model uses \-log(pr).
.PP
\&\fBslmbuild \-l \-n 3 \-o all.slm \-w 200000 \-c 0,3,2 \-d GT,8,0.9995 \-d ABS \-d ABS \-b 10,11,12 \-e 9 all.id3gram\fR
.SH AUTHOR
.IX Header "AUTHOR"
Originally written by Phill.Zhang <phill.zhang@sun.com>.
Currently maintained by Kov.Chai <tchaikov@gmail.com>.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
\&\fBids2ngram\fR(1), \fBslmprune\fR(1).