Hi Martin,
Charlie, this is not a problem. Floating point rounding error only comes into play when you are doing computations using numeric operations. Extent computation only uses comparison operations, and these are exact.
Ah - that's interesting. So if a BBox is computed for a geometry and it has the
max and min x and y being exactly the same, it can be determined to be a Point, with no worry about error. (Conversely, if a geometry is not a point, it must have at least two coordinates with different Xs or Ys, and so its BBox will have a non-zero extent.
Thanks for the information. Ok, then I'll see if I can fix up the bbox2 to geometry conversion so it returns a point if either xmin=xmax or ymin=ymax. Currently it returns an invalid polygon - same problem that envelope had.
Charlie
smime.p7s
Description: S/MIME Cryptographic Signature
_______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
