[postgis-users] problem to transform coordinates

Paragon Corporation lr at pcorp.us
Wed Jul 30 22:13:51 PDT 2008


Maybe there is something wrong with your entry in the spatial_ref_sys table
for that SRID.  Also provide two sample 22523 points and what the
ST_Transform looks like.
 
Also please use ST_Transform if you are using a PostGIS install > 1.2
 
What does 
 
SELECT proj4text 
FROM spatial_ref_sys 
WHERE srid = 22523
 
give you?
 
Mine gives 
+proj=utm +zone=23 +south +ellps=intl +towgs84=-206,172,-6,0,0,0,0 +units=m
+no_defs 
 
Hope that helps,
Regina

  _____  

From: postgis-users-bounces at postgis.refractions.net
[mailto:postgis-users-bounces at postgis.refractions.net] On Behalf Of Felipe
Fedel Pinto
Sent: Wednesday, July 30, 2008 7:26 PM
To: postgis-users at postgis.refractions.net
Subject: [postgis-users] problem to transform coordinates


To transform coordinates in PostGis I use the followed function:

UPDATE <table> SET <new_geometry_column> =
transform(<original_geometry_column>,<new_SRID>);

I have been having a weird problem when I try to transform coordinates that
are in a SRID=22523. 
Ex: I have to transform them to a SRID=4326

UPDATE coordsformiga SET coord_4326 = transform(coord_22523,4326);

where coordsformiga is the table,
          coord_22523 is the original geometry column with the coordinates
in a SRID=22523
          coord_4326 I'd be the geometry column with the coordinates
transformed in a SRID=4326

the problem is:
After the function, in the geometry column (coord_4326), all of the 97
coordinates have the same values.
But it's happening only with a SRID=22523.

Anybody knows what is happening??

thanks


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