[postgis-users] PostGIS analogues to ArcInfo geoprocessing functions

[Paul Ramsey]

On Thu, Jan 29, 2009 at 8:42 AM, Martin Davis <mbdavis at refractions.net> wrote:
> The basic approach to computing polygon overlays has been well-understood
> for a long time (although this does not imply well-documented!).  The
> implementation however is quite tricky, especially if performance and
> robustness is required.  There is a notable lack of open-source existing
> implementations - which should be an indication of just how difficult this
> really is.

I believe the vector component of GRASS includes overlay (and of
course the raster component does too).

http://grass.itc.it/grass64/manuals/html64_user/v.overlay.html

P.