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Created Sep 8, 2010
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I have an issue with co-ordinate transform from within Django, to do with SRID 29902 (Irish National Grid).
/usr/share/proj/epsg contains the following line:
<29902> +proj=tmerc +lat_0=53.5 +lon_0=-8 +k=1.000035 +x_0=200000 +y_0=250000 +a=6377340.189 +b=6356034.447938534 +units=m +no_defs +datum=ire65 <>
And this works from the command line:
$ cs2cs -f "%.15f" +init=epsg:29902 +to +init=epsg:4326
326905 369342
-6.039196526852078 54.556479046321378 53.590400303713977
In my PostGIS database I have the following:
=> select srid,proj4text from spatial_ref_sys where srid=29902;
29902 | +proj=tmerc +lat_0=53.5 +lon_0=-8 +k=1.000035 +x_0=200000 +y_0=250000 +a=6377340.189 +b=6356034.447938534 +units=m +no_defs +datum=ire65
And this too works fine:
=> select st_astext(st_transform(st_geomfromtext('POINT(326905 369342)', 29902), 4326));
POINT(-6.03919652685208 54.5564790463214)
However ,if I try the following from python shell this is what I get:
>>> from django.contrib.gis.gdal import OGRGeometry
>>> print OGRGeometry('POINT(326905 369342)', 29902).transform(4326, True)
POINT (-6.038191373300764 54.556391716974865)
Which is what the other two options give if I remove the needed "+datum=ire65" bit.
So what is GDAL calling to do the transformation, and what do I change to make it
work as proj/PostGIS? I'm running proj 4.6.0 (with edited epsg file to match 4.7),
GDAL 1.5.2, Django 1.1.1.
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