Works great! Thanks everyone! On Tue, Nov 24, 2009 at 12:47 PM, Paul Ramsey <[email protected]> wrote: > select st_x(st_centroid(geom)) as x, st_y(st_centroid(geom)) as y from > mytable; > > On Tue, Nov 24, 2009 at 9:46 AM, Robert Hicks <[email protected]> wrote: >> Great thanks! I think either ST_PointOnSurface() or ST_Centroid() >> should be fine, but now I need convert the geometry string into >> latitude and longitude (Sorry, I should have been more clear before >> what I was ultimately looking for). >> >> On Tue, Nov 24, 2009 at 12:40 PM, Paul Ramsey <[email protected]> >> wrote: >>> Ah, POINT(avg(X), avg(Y))... >>> >>> On Tue, Nov 24, 2009 at 9:38 AM, Kevin Neufeld <[email protected]> >>> wrote: >>>> Maxime van Noppen wrote: >>>>> >>>>> Paul Ramsey wrote: >>>>>> >>>>>> Use ST_Centroid() then. It's just the mid-point of the bbox, so it's >>>>>> fast to calculate. >>>>> >>>>> It might be outside the polygon though. >>>>> >>>> >>>> In which case, if it matters, use ST_PointOnSurface(). >>>> >>>> Paul, just a clarification, I believe centroid calculates the geometric >>>> centre of a geoemtry or "centre of mass" and not the mid-point of the bbox. >>>> Here are a few pictorial examples: >>>> http://postgis.org/documentation/manual-1.5SVN/ST_Centroid.html >>>> >>>> -- Kevin >>>> _______________________________________________ >>>> 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 >>> >> >> >> >> -- >> web http://www.hyxspace.com >> aim hyx1138 >> _______________________________________________ >> 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 >
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