[postgis-users] Different results in datum transform pg v2 vs pg v1

[David Fawcett]

We are finally able to retire one of our older servers running an old
version of PostGIS and we are migrating everything over to a new install.

One thing that I am noticing is that I am getting different behavior
between the two versions when transforming some values from 4267 to 4326.

The Old Server:

SELECT Postgis_Version();
1.3 USE_GEOS=1 USE_PROJ=1 USE_STATS=1

SELECT
ST_Y(ST_Transform(ST_SetSRID(ST_Point(-94.884720995369,47.4732852509464),4267),4326))
AS lat,

ST_X(ST_Transform(ST_SetSRID(ST_Point(-94.884720995369,47.4732852509464),4267),4326))
AS lon;

47.4732375024506 | -94.8849980111078



The New Server
SELECT Postgis_Version();
2.1 USE_GEOS=1 USE_PROJ=1 USE_STATS=1

SELECT
ST_Y(ST_Transform(ST_SetSRID(ST_Point(-94.884720995369,47.4732852509464),4267),4326))
AS lat,

ST_X(ST_Transform(ST_SetSRID(ST_Point(-94.884720995369,47.4732852509464),4267),4326))
AS lon;

47.4732852509464 | -94.884720995369

This issue feels familiar, but I couldn't find anything about it when
searching.  Can anyone shed some light?

Thanks,

David.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20150605/504cee38/attachment.html>