.\"------------------------------------------------------------
.\" Id - set Rv,revision, and Dt, Date using rcs-Id tag.
.de Id
.ds Rv \\$3
.ds Dt \\$4
..
.Id $Id: mg_perf_hash_build.1 3745 2003-02-20 21:20:24Z mdewsnip $
.\"------------------------------------------------------------
.TH mg_perf_hash_build 1 \*(Dt CITRI
.SH NAME
mg_perf_hash_build \- generate an order-preserving hash function for the stemmed dictionary
.SH SYNOPSIS
.B mg_perf_hash_build
[
.B \-h
]
[
.BI \-r " rndseed"
]
[
.BI \-d  " directory"
]
.if n .ti +9n
.BI \-f " name"
.SH DESCRIPTION
.B mg_perf_hash_build
generates an order-preserving hashing function from the compressed
stemmed dictionary and writes it out to disk.
.BR mg_passes (1)
will make use of the hash function when it builds the inverted file.
.SH OPTIONS
Options may appear in any order.
.TP "\w'\fB\-d\fP \fIdirectory\fP'u+2n"
.B \-h
This displays a usage line on
.IR stderr .
.TP
.BI \-r " rndseed"
This specifies the random seed to be used in the generation of the
hash function; it must be an integer.  If this is not specified, the
current time will be used as the random seed.
.TP
.BI \-d " directory"
This specifies the directory where the document collection can be found.
.TP
.BI \-f " name"
This specifies the base name of the document collection.
.SH ENVIRONMENT
.TP "\w'\fBMGDATA\fP'u+2n"
.SB MGDATA
If this environment variable exists, then its value is used as the
default directory where the
.BR mg (1)
collection files are.  If this variable does not exist, then the
directory \*(lq\fB.\fP\*(rq is used by default.  The command line
option
.BI \-d " directory"
overrides the directory in
.BR MGDATA .
.SH FILES
.TP 20
.B *.invf.dict
Stemmed dictionary.
.TP
.B *.invf.dict.hash
Data for a order-preserving perfect hash function.
.SH "SEE ALSO"
.na
.BR mg (1),
.BR mg_compression_dict (1),
.BR mg_fast_comp_dict (1),
.BR mg_get (1),
.BR mg_invf_dict (1),
.BR mg_invf_dump (1),
.BR mg_invf_rebuild (1),
.BR mg_passes (1),
.BR mg_text_estimate (1),
.BR mg_weights_build (1),
.BR mgbilevel (1),
.BR mgbuild (1),
.BR mgdictlist (1),
.BR mgfelics (1),
.BR mgquery (1),
.BR mgstat (1),
.BR mgtic (1),
.BR mgticbuild (1),
.BR mgticdump (1),
.BR mgticprune (1),
.BR mgticstat (1).