Bob, Not quite clear what you are looking for here. So are you trying to put your text identifier on a hole in a geometry? What if there is no hole? Also the centroid of a geometry is not guaranteed to lie on the geometry so even if you turned empty space into non-empty so you can take the centroid of it, the centroid may not be in the hole. To get the centroid of a hole, I think you need to turn it into non-hole (like turning anti-matter into matter). you can do this by say taking the exterior of the covering area, and then using ST_Difference. The result would be the holes turned into geometries
_____ From: [email protected] [mailto:[email protected]] On Behalf Of Bob Pawley Sent: Saturday, March 28, 2009 11:24 PM To: PostGIS Users Discussion Subject: [postgis-users] Finding Empty Space Hi The expression st_isempty returns a boolean set. Is there any method of returning the centroid coordinates of an empty space wihtin a given geometry? I want to add a text identifier to a geometry without it being lost in the clutter. Bob
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