ngram-merge.1

这是一款很好用的工具包

.\" $Id: ngram-merge.1,v 1.7 2004/12/03 17:59:01 stolcke Exp $
.TH ngram-merge 1 "$Date: 2004/12/03 17:59:01 $"  "SRILM Tools"
.SH NAME
ngram-merge \- merge N-gram counts
.SH SYNOPSIS
.B ngram-merge
[\c
.BR \-help ]
[\c
.B \-write
.IR outfile ]
[\c
.BR \-float-counts ]
[\c
.BR -- ]
.I infile1
.I infile2
\&...
.SH DESCRIPTION
.B ngram-merge 
reads two or more lexicographically sorted N-gram count files
(as produced by 
.BR "ngram-count -sort" )
and outputs the merged, sorted counts.
The output is thus suitable for subsequent merging steps.
.PP
The input format consists of one N-gram count per line,
.br
.I
	word1 word2 ... wordn count
.P
.br
The lines must be sorted lexicographically on the words, leftmost first.
The input may contain N-grams of different lengths.
.PP
Each filename argument can be a plain ASCII count file, or a 
compressed file (name ending in .Z or .gz), or ``-'' to indicate
stdin/stdout.
.PP
.B ngram-merge 
is recommended in cases where the full counts would far exceed 
available real memory.
Although an arbitrary number of input count files is accepted,
it is best to use the program as follows.
First, partition the input text into the largest chunks so that
.B ngram-count
can run in real memory.
Then merge the resulting sorted counts using
.B ngram-merge
pairwise, and continue doing so in a binary tree pattern until a
single count file containing all N-grams remains.
This procedure is automated by the
.B make-batch-counts
and
.B merge-batch-counts
scripts.
.SH OPTIONS
.PP
Each filename argument can be an ASCII file, or a 
compressed file (name ending in .Z or .gz), or ``-'' to indicate
stdin/stdout.
.TP
.B \-help
Print option and usage summary.
.TP
.B \-version
Print version information.
.TP
.BI \-write " outfile"
Write merged counts to
.IR outfile ,
instead of standard output.
.TP
.B \-float-counts
Process counts as floating point numbers.
By default counts are assumed to be unsigned integers.
.TP
.B \-\-
Indicates the end of options, in case the first input filename begins
with ``-''.
.SH "SEE ALSO"
ngram-count(1), ngram(1), training-scripts(1).
.SH AUTHOR
Andreas Stolcke <[e-mail]>
.br
Copyright 1995\-2004 SRI International