Mark Cave-Ayland wrote:
Stephen Woodbridge wrote:
Hi guys,
This is looking like it might be a bug on version "POSTGIS="1.3.3"
GEOS="3.0.0-CAPI-1.4.1" PROJ="Rel. 4.6.0, 21 Dec 2007" USE_STATS"
which I know is ancient, but upgrading is not trivial.
What I am trying to do is construct a shape in 900913 in meters and
then rotate, transform it to 4326 and translate it to a location.
The problem is the transform does not look correct. To just rough out
the math, 4030 meters should be about 0.036202 degrees based on
4030/40075016*360 = 0.036202 but st_transform is giving back numbers
like -5.67596869587729e-09
Is this a known problem on this version?
Is my logic faulty?
Is there a better way to do this?
Thanks,
-Steve
Hi Steve,
The first thing I would suggest is that you run the same query on a
spare fresh 1.4/1.5 installation and see what happens. The
transformation code had a good tidy up and some logic corrections within
that timeframe, including better reporting of error messages.
Hi Mark, et al,
1) Can someone run this query 1.4 and report back the results:
SELECT astext(st_linefromtext('LINESTRING(0 0,4030 0,4030 4030,0 4030)',
900913)),
astext(st_rotate(st_linefromtext('LINESTRING(0 0,4030 0,4030
4030,0 4030)', 900913), radians(90))),
astext(st_transform(st_rotate(st_linefromtext('LINESTRING(0
0,4030 0,4030 4030,0 4030)', 900913), radians(90)), 4326)),
astext(st_translate(st_transform(st_rotate(st_linefromtext('LINESTRING(0
0,4030 0,4030 4030,0 4030)', 900913), radians(90)), 4326),-71.26162,
42.30028));
It assumes that you have 900913 loaded in your spatial_ref_sys table.
2) Does anyone know where I can get postgis 1.4 for debian lenny. I can
get postgresql 8.4 from from backports.org, but they do not have postgis
there. Ideally, at package like postgresql-8.3-postgis based on 1.4
would be simplest, but I'm willing to take a couple of days to dump and
reload all my databases to upgrade to postgresql 8.4 also.
Thanks,
-Steve
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