[GRASS-dev] v.info Projection info

Huidae Cho grass4u at gmail.com
Tue Oct 24 03:33:03 EDT 2006


On Tue, Oct 24, 2006 at 09:22:40AM +0200, Maciej Sieczka wrote:
> Huidae Cho wrote:
> > Hi,
> > 
> > I found that Vect_open_old_head() does not set Map.proj:
> 
> <snip>
> 
> > For this reason, v.info always prints out "Projection: x,y (zone ...)"
> > (Map.proj == 0 == PROJECTION_XY) regardless of its actual projection.
> > It seems like to me there is no projection info in vector files.  If
> > individual vector files cannot have a different projection from its
> > location, why doesn't v.info use G_database_projection_name() like
> > r.info does?
> 
> Hi,
> 
> Since this issue is rised, I'd like throw my 0,01 PLN in. Why, in the
> first place, does r.info or v.info even try to print the projection
> info? I don't think they should. It is pointless - all the maps within
> one Location have the same projection anyway. For querying the
> Location's projection info there is g.proj -p. And also the g.region
> -p, but same as in case of *.info modules, I believe it shouldn't do
> that - g.region should be concerned with the region extent and
> resolution only. It would be enough if it just distunguished between
> lat/long, projected and xy, and not go into ellipsoids/datums/zones
> details and stuff - there is g.proj for that.

I've been thinking about that.  I personally like only one way for one
task.  We can avoid inconsistent/erroneous outputs in this way.

Huidae

> 
> What do you think? Removing this code alltogether from *.info would let
> us get rid of bogus, missleading r.info output in the kind of
> "Projection: Latitude-Longitude (zone 0)" as well. Propably not a plan
> for GRASS 6, but how about 7?
> 
> Maciek




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