NAME

       ids2ngram - generate n-gram data file from ids file

SYNOPSIS

       ids2ngram [option]... ids_file...

DESCRIPTION

       ids2ngram generates idngram file, which is a sorted [id1,..,idN,freq] array, from binary
       id stream files. Here, the id stream files are always generated by mmseg or slmseg.
       Basically, it finds all occurrence of n-words tuples (i.e. the tuple of (id1,..,idN)), and
       sorts these tuples by the lexicographic order of the ids make up the tuples, then write
       them to specified output file.

INPUT

       The input file is presented as a binary id stream, which looks like:
           [id0,...,idX]

OPTIONS

       All the following options are mandatory.

       -n,--NMax N
           Generates N-gram result. ids2ngram does only support uni-gram, bi-gram, and trigram,
           so any number not in the range of 1..3 is not valid.

       -s,--swap swap-file
           Specify the temporary intermediate file.

       -o, --out output-file
           Specify the result idngram file, e.g. the array of [id1, ..., idN, freq]

       -p, --para N
           Specify the maximum n-gram items per paragraph. ids2ngram writes to the temporary file
           on a per-paragraph basis. Every time it writes a paragraph out, it frees the
           corresponding memory allocated for it. When your computer system permits, a higher N
           is suggested. This can speed up the processing speed because of less I/O.

EXAMPLE

       Following example will use three input idstream file idsfile[1,2,3] to generate the
       idngram file all.id3gram. Each para (internal map size or hash size) would be 1024000,
       using swap file for temp result. All temp para result would eventually be merged to got
       the final result.

       ids2ngram -n 3 -s /tmp/swap -o all.id3gram -p 1024000 idsfile1 idsfile2 idsfile3

AUTHOR

       Originally written by Phill.Zhang <phill.zhang@sun.com>.  Currently maintained by Kov.Chai
       <tchaikov@gmail.com>.

SEE ALSO

       mmseg(1), slmseg(1), slmbuild (1).