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.TH mg_weights_build 1 \*(Dt CITRI
.SH NAME
mg_weights_build \- builds the approximate weights file
.SH SYNOPSIS
.B mg_weights_build
[
.B \-h
]
[
.BI \-b " num-bits"
]
.if n .ti +17n
[
.BI \-d " directory"
]
.BI \-f " name"
.SH DESCRIPTION
.B mg_weights_build
is the program that generates the exact and approximate weights 
files.  To do this, it uses the inverted file
and dictionary.
.SH OPTIONS
Options may appear in any order.
.TP "\w'\fB\-d\fP \fIirectory\fP'u+2n"
.B \-h
This displays a usage line on
.IR stderr .
.TP
.BI \-b " num-bits"
This specifies the number of bits of precision that should be used for
the approximate weights.  If not specified, it defaults to 8.
.TP
.BI \-d " directory"
This specifies the directory where the document collection is.
.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 mg
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
Inverted file.
.TP
.B *.invf.dict
Compressed stemmed dictionary.
.TP
.B *.text.idx
Index into the compressed documents.
.TP
.B *.weight
The exact weights file.
.TP
.B *.weight.approx
Approximate document weights.
.SH "SEE ALSO"
.na
.BR mg_compression_dict (1),
.BR mg_fast_comp_dict (1),
.BR mg_invf_dict (1),
.BR mg_passes (1),
.BR mg_perf_hash_build (1),
.BR mg_stem_idx (1)