Changes between Version 8 and Version 9 of BluePrintGISStorage

Timestamp:

09/26/10 21:21:35 (15 years ago)

Author:

Fran Boon

Comment:

--

BluePrintGISStorage

@@ -24 +24 @@
 ST_Intersects(geography, geography) returns boolean
 
+ST_Centroid(geometry) returns a point that is approximately on the center of mass of the input argument. This simple calculation is very fast, but sometimes not desirable, because the returned point is not necessarily in the feature itself. If the input feature has a convexity (imagine the letter ‘C’) the returned centroid might not be in the interior of the feature.
+ST_PointOnSurface(geometry) returns a point that is guaranteed to be inside the input argument. It is substantially more computationally expensive than the centroid operation
+
 }}}