[GRASS-dev] v.info Projection info

Maciej Sieczka tutey at o2.pl
Tue Oct 24 03:22:40 EDT 2006

Huidae Cho wrote:
> Hi,
> I found that Vect_open_old_head() does not set Map.proj:


> 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?


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.

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?


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