[postgis-users] transform error for swiss projection

[Frank Warmerdam]

Johannes Bühler wrote:
> Hi, 
> im trying to transform a geometry from wgs84 to the swiss epsg:2056 or epsg:21781. i compiled postgis 0.9 with postgresql 8.0beta4 and have the most current version of proj4 (4.4.9) installed as well. but when i execute the folling statement 
> 
> select transform(GeometryFromText('POINT(7.675133 47.533609)',4326), 21781);
> 
> i get the following error message.
> 
> FEHLER:  tranform: couldnt parse proj4 output string
> KONTEXT:  PL/pgSQL function "transform" line 2 at return
> 
> using other target projections it works.
> 
> using the most current gdal 1.2.3 the conversation is fine. But there has been the same problem before as described in 
> 
> http://bugzilla.remotesensing.org/show_bug.cgi?id=423
> 
> so probably its the same problem 
> 
> Thanks for any help
> 
> with kind regards
> 
> Johannes Buehler

Johannes,

I would suggest trying to update the proj4text field in the spatial_ref_sys
table to be as follows for the SRID in question:

+proj=somerc +lat_0=46.95240555555556 +lon_0=7.439583333333333 +x_0=2600000
+y_0=1200000 +ellps=bessel +towgs84=674.374,15.056,405.346,0,0,0,0 +units=m +no_defs

I believe the problem is that the spatial_ref_sys table is out of date since
I ignored Paul's last request for a new dump.

BTW, a dump of data for the spatial_ref_sys table can be done like this
(from within the gdal/data directory assuming you have python support):

   ../pymod/epsg_tr.py -postgis -list pcs.csv > srs.sql
   ../pymod/epsg_tr.py -postgis -list gcs.csv >> srs.sql

This dumps all the EPSG pcs and gcs values into a ready to run SQL
script.  You might need to first drop your existing spatial_ref_sys table if
you have one.  I have placed the above .sql file at:

  http://home.gdal.org/~warmerdam/srs.sql

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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