[GRASSLIST:2413] Re: v.proj problems

morten at untamo.net morten at untamo.net
Fri Jan 30 16:13:02 EST 2004


Please do what Paul is asking for: send the output of g.region -p and 
g.projinfo for both your lonlat and utm location. Then maybe we can help 
you.

 

On Fri, 30 Jan 2004, Ian Macmillan wrote:

> Quoting Paul Kelly <paul-grass at stjohnspoint.co.uk>:
> 
> > On Thu, 29 Jan 2004, Ian Macmillan wrote:
> > 
> > > Hi all, I am trying to convert some data from a lat-long projection to a
> > utm
> > > projection.  I am using v.proj, but the projected vectors come out in the
> > wrong
> > > location (northern hemisphere, when they should be southern).  The area I
> > am
> > > using is in Chile, so it is in the southern hemisphere, I was thinking
> > this
> > > might be the problem?  The v.info results are listed here.
> > >
> > >  Projection: UTM (zone 19)
> > >  |N:    8062436    S:    3775859
> > >  |E:     774210    W:    -213663
> > >
> > >  Projection: Latitude-Longitude (zone 0)
> > >  |N:        -18    S:        -56
> > >  |E:        -66    W:        -76
> > >
> > > Both projections use the wgs84 datum.
> > 
> > What are the PROJ_INFO files for your locations? (g.projinfo)
> > And the output of g.region -p ?
> > I'm thinking it should say zone -19, not 19, although that wouldn't affect
> > v.proj which should get all the projection information from PROJ_INFO. If
> > it has zone: 19 then it should also contain south: defined although
> > zone: -19 on its own should also work.
> > 
> Hey all, so I am a bit of an idiot, the vector I am trying to import extends
> much farther than zone 19.  I figured this must be the main problem.  However,
> when I converted the vector to a raster (v.to.rast) and cut the raster down to
> an area that is definitely within zone 19 (using r.mapcalc, and resizing the
> region), using r.proj (in the utm location) only yields an error message saying
> the proposed raster lies outside of my current region (even though the region
> was set to fit an area larger than the raster.
> 
> Ack, i am lost, i have used r.proj successfully many times, but something seems
> to be wrong here.
> 
> My proj_info file says zone: 19 and south: defined in the utm location.
> 
> Any ideas?
> Thanks a bunch, ian
> 




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