.TH v.to.sites 1 "" "" "" ""
.SH NAME
\*Lv.to.sites\*O  - Converts point data in a binary
GRASS vector map layer into a GRASS site_lists
file.
.br
(GRASS Vector Program)
.SH SYNOPSIS
\*Lv.to.sites\*O
.br
\*Lv.to.sites help\*O
.br
\*Lv.to.sites [-acCid\*O] \*Linput=\*Oname 
\*Loutput=\*Oname 
[\*Ldmax=\*Ovalue]
.SH DESCRIPTION
The v.to.sites program extracts data from a GRASS vector map layer
and stores output in a new GRASS site_lists file.
If  \*L-a\*O flag is selected, v.to.sites extracts all vertices from
a vector file, if not selected, it extracts site (point) features only,
ignoring lines and areas. 
If  \*L-i\*O flag is selected then, for each line, if the distance between
any two vertices on this line is greater that \*Ldmax\*O, additional
points are added to keep the distance withing \*Ldmax\*O range.
The resulting sites map layer can be used with such programs as 
\*Ld.sites\*O.
.PP
The user can run the program non-interactively by
specifying the names of an existing vector \*Linput\*O map
layer and a new site list file to be \*Loutput\*O on the
command line.  The program will be run interactively if the
user types \*Lv.to.sites\*O without arguments on the
command line.  In this case, the user will be prompted to
enter parameter values through the standard user interface
described in the manual entry for
\*Lparser\*O.
.SH OPTIONS:
.SH Flags:
.VL 4m
.LI "\*L-a\*O 
Outputs all vertices (instead of site data only) from
vector file to site file
.LI "\*L-c\*O 
The Category NUMERIC data is used instead of attribute as a
site description
.LI "\*L-C\*O 
The Category TEXT data is used instead of attribute as a
site description
.LI "\*L-i\*O 
Additional sites are added between each 2 points on a
line if the distance between them is greater than specified
\*Ldmax\*O.  (valid only when \*L-a\*O is used)
.LI "\*L-d\*O 
Write attribute as double instead of cat.
.PP
If any of the sites have been labeled in 
\*Lv.digit\*O,
then the resultant site list will contain category
information (or attribute in case \*L-a\*O was used but
\*L-c\*O was not).  If none of the sites are labeled, a
binary (0/1) site list file will be produced.
.LE
.SH Parameters:
.VL 4m
.LI "\*Linput=\*Oname 
Name of an existing binary vector map layer from which
site data are to be extracted.
.LI "\*Loutput=\*Oname 
Name to be assigned to the resultant site_lists file.
.LI "\*Ldmax=\*Ovalue 
Maximum distance between points (valid only when
\*L-a\*O and \*L-i\*O are used)
.LE
.SH SEE ALSO
\*Ld.sites\*O,
\*Ls.db.rim\*O,
\*Ls.menu\*O,
\*Lv.db.rim\*O,
\*Lv.digit\*O
and
\*Lparser\*O
.SH AUTHOR
Dave Gerdes,
.br
Irina Kosinovsky, 
.br
U.S.Army Construction Engineering 
Research Laboratory