Just skip the projections altogether. select st_distance_sphere(st_makepoint(28.060455, -26.056947),st_makepoint(18.3793284, -33.9228922))
This falls apart for queries with large tables, etc, because there's no _sphere equivalent of st_dwithin that can leverage an index well. P. On Sun, Jun 14, 2009 at 9:20 AM, africa4you<[email protected]> wrote: > > Hi > > I have two points in different SRID's and would like to calculate the > distance between them, unfortunately this type of operation doesnt seem to > be valid (Operation on two GEOMETRIES with different SRIDs ). Any help in > solving this issue would be appreciated. Please see the sql below: > > Kind regards > > Grant Edwards > > SELECT postgis_full_version() > "POSTGIS="1.3.3" GEOS="3.0.0-CAPI-1.4.1" PROJ="Rel. 4.6.0, 21 Dec 2007" > USE_STATS" > > > > SELECT utmzone(ST_Centroid(setsrid((makepoint(28.060455, > -26.056947)),4326))); //Johannesburg (utmzone = 32735) > EPSG Projection 32735 - WGS 84 / UTM zone 35S > http://spatialreference.org/ref/epsg/32735/ > > SELECT utmzone(ST_Centroid(setsrid((makepoint(18.3793284, > -33.9228922)),4326))); //Cape Town (utmzone = 32734) > EPSG Projection 32734 - WGS 84 / UTM zone 34S > http://spatialreference.org/ref/epsg/32734/ > > SELECT ST_Distance(ST_Transform(setsrid((makepoint(28.060455, > -26.056947)),4326),utmzone(ST_Centroid(setsrid((makepoint(28.060455, > -26.056947)),4326)))) , > ST_Transform(setsrid((makepoint(18.3793284, > -33.9228922)),4326),utmzone(ST_Centroid(setsrid((makepoint(18.3793284, > -33.9228922)),4326))))) as dist_meters > > > ERROR: Operation on two GEOMETRIES with different SRIDs > -- > View this message in context: > http://www.nabble.com/GEOMETRIES-with-different-SRIDs-tp24022339p24022339.html > Sent from the PostGIS - User mailing list archive at Nabble.com. > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users > _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
