"Some day I hope to get this into JTS/GEOS"... Go, Martin, go!
Martin Davis wrote: > That should work. You may also have the problem of determining which > of the resultant polygons fell on each side of the drawn line. The > usual way to do this would be to run some point-in-polygon queries. > > It's amazing how much this use case comes in many different venues > (PostGIS, GUI tools, etc). Some day I hope to get this into JTS/GEOS > as a provided operation, at which point this will be much easier to > accomplish. > > James Beaudoin wrote: >> I think the steps below will work but I have one question. I am >> creating an application that allows a user to split a polygon by >> drawing a linestring across the polygon they wish to change. The >> crossing linestring has parts that are outside the polygon and I want >> to remove that before I geomunion. What's the easiest way to do that? >> >> - extract the lines that make up the polygon >> - add to this your crossing linestring >> - geomunion the lines together. >> - polygonize the union-ed set >> >> Thanks, >> >> Jim >> _______________________________________________ >> postgis-users mailing list >> postgis-users@postgis.refractions.net >> http://postgis.refractions.net/mailman/listinfo/postgis-users >> > -- Regards, Chris Hermansen mailto:[EMAIL PROTECTED] tel+1.604.714.2878 · fax+1.604.733.0631 · mob+1.778.232.0644 Timberline Natural Resource Group · http://www.timberline.ca 401 · 958 West 8th Avenue · Vancouver BC · Canada · V5Z 1E5 _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
