[postgis-users] Bug?

[Michael Fuhr]

On Wed, Feb 07, 2007 at 02:16:20PM -0000, Pedro Doria Meunier wrote:
> During my difficulties with the distance() function (which btw, returns
> values (in srid=4326) that don't make sense to me) I found this:

distance() returns distances in the same units that the geometries
have.  If the units are degrees then distance() returns degrees;
if the units are meters then distance returns meters; if the units
are stadia then distance() returns stadia.

> A query like this works as expected (geom with srid=4326):
> 
> select transform(mygeom, 2942) from my_table;

You say "works as expected" -- what are you expecting?  What's the
input and what's the output?  Without AsText() or AsEWKT() the above
query should return something like

01010000207E0B0000000000000000F07F000000000000F07F

> but when one tries this:
> 
> select astext(transform(mygeom,2942)) from my table
> 
> the result is:
> 
> "POINT(inf inf)"

Apparently the coordinates can't be translated to SRID 2942, perhaps
because they're not really in the SRID specified in their original
geometry.  For example:

SELECT AsText(Transform(GeomFromEWKT('SRID=4326;POINT(3241 -1648)'), 2942));
     astext     
----------------
 POINT(inf inf)
(1 row)

This doesn't work because (3241 -1648) isn't really in SRID 4326,
whose coordinates should be longlat.

-- 
Michael Fuhr