.TH v.proj 1grass "" "GRASS 6.4.4" "Grass User's Manual"
.SH NAME
\fI\fBv.proj\fR\fR  - Re-projects a vector map from one location to the current location.
.SH KEYWORDS
vector, projection, transformation
.SH SYNOPSIS
\fBv.proj\fR
.br
\fBv.proj help\fR
.br
\fBv.proj\fR [\-\fBlz\fR]  [\fBinput\fR=\fIname\fR]  \fBlocation\fR=\fIname\fR  [\fBmapset\fR=\fIname\fR]   [\fBdbase\fR=\fIpath\fR]   [\fBoutput\fR=\fIname\fR]   [\-\-\fBoverwrite\fR]  [\-\-\fBverbose\fR]  [\-\-\fBquiet\fR] 
.SS Flags:
.IP "\fB\-l\fR" 4m
.br
List vector maps in input location and exit
.IP "\fB\-z\fR" 4m
.br
Assume z co-ordinate is ellipsoidal height and transform if possible
.br
3D vector maps only
.IP "\fB\-\-overwrite\fR" 4m
.br
Allow output files to overwrite existing files
.IP "\fB\-\-verbose\fR" 4m
.br
Verbose module output
.IP "\fB\-\-quiet\fR" 4m
.br
Quiet module output
.PP
.SS Parameters:
.IP "\fBinput\fR=\fIname\fR" 4m
.br
Name of input vector map
.IP "\fBlocation\fR=\fIname\fR" 4m
.br
Location containing input vector map
.IP "\fBmapset\fR=\fIname\fR" 4m
.br
Mapset containing input vector map
.IP "\fBdbase\fR=\fIpath\fR" 4m
.br
Path to GRASS database of input location
.IP "\fBoutput\fR=\fIname\fR" 4m
.br
Name for output vector map (default: input)
.PP
.SH DESCRIPTION
\fIv.proj\fR allows a user to convert a vector map in a specified mapset
of a specified location (different from current) with projection of input
location to the vector map in a current mapset of current location with
projection of current location (both projections are defined by
corresponding PROJ_INFO files). The projection information is taken from the
current PROJ_INFO files, as set and viewed with
\fIg.proj\fR.
.SH NOTES
If \fBoutput\fR is not specified it is set to be the same as input map
name.
.br
If \fBmapset\fR is not specified, its name is assumed to be the same
as the current mapset's name.
.br
If \fBdbase\fR is not specified it is assumed to be the current
database. The user only has to specify \fBdbase\fR if the source
location is stored in another separate GRASS database.
.PP
\fIv.proj\fR supports general datum transformations, making use of the
\fIPROJ.4\fR co-ordinate system translation library.
.PP
In order to preserve spatial detail, it is recommended to densify linear 
features with \fIv.split\fR before 
reprojecting. Depending on the source and target CRS 
(Coordinate Reference System), geometries can be substantially 
deformed (straight lines become curves, squares become trapezoids, etc). 
In these cases densification of linear features can help to avoid 
topological errors.
.SH EXAMPLES
\fC
.DS
.br
v.proj in=mymap location=latlong mapset=user1
.br
.DE
\fR
.SH REFERENCES
PROJ 4: Projection/datum support library.
.PP
\fBFurther reading\fR
.RS
.IP
 ASPRS Grids and Datum
.IP
 MapRef - The Collection of Map Projections and Reference Systems for Europe
.IP
 Projections Transform List (PROJ4)
.RE
.SH SEE ALSO
\fI
r.proj,
g.proj,
g.setproj,
i.rectify,  
r.stats,  
v.sample,
v.split,
v.surf.idw,
v.surf.rst
\fR
.SH AUTHORS
Irina Kosinovsky, US ARMY CERL
.br
M.L. Holko, USDA, SCS, NHQ-CGIS
.br
R.L. Glenn, USDA, SCS, NHQ-CGIS
.PP
\fILast changed: $Date: 2014-01-13 10:31:51 +0100 (Mon, 13 Jan 2014) $\fR
.PP
Full index
.PP
© 2003-2014 GRASS Development Team