Craig, Yes as Webb said - that would help a lot to see some of your problematic geometries.
Looking at your query it looks perfectly fine. The only reason I can think why you would be missing polygons is your condition of a.buf_dist = 1 (I am assuming you are not expecting to see any bio.bnd_bufs where the buf_dist <> 1)? And a far out reason - you really have Polylines (line strings) and not Polygons. On screen they would look more or less the same unless you have them shaded in. Hope that helps, Regina -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Webb Sprague Sent: Sunday, October 21, 2007 10:49 PM To: PostGIS Users Discussion Subject: Re: [postgis-users] Repost: Intersection not working properly Can you post astext() version of your geometries and srids so the list members can try to reproduce? (Disregard if you already did in your last email). -W On 10/21/07, Craig Feuerherdt <[EMAIL PROTECTED]> wrote: > This is a re-post of a message from last week. I still have not resolved the > issue. > > I am trying to clip one table using the features in another. My query is as > follows; > > drop table bio.bnd_evc; > create table bio.bnd_evc as > select a.buf_dist, b.bio_no, b.bio_code, b.evc, b.constcde, b.consstat , > b.density, intersection(a.the_geom, b.the_geom) as the_geom > from bio.bnd_buf as a, bio.evc as b > where a.the_geom && b.the_geom > and a.buf_dist = 1 > and intersects(a.the_geom, b.the_geom) > > Both tables have a GIST index. The query returns a table, however there are > several polygons from the evc table, within the bnd_buf table, that are > missing. I thought those missing polygons may have had invalid geometries > (which is not the case as isvalid(evc.the_geom) returns TRUE for all > geometries) and buffered the evc layer by 0, however this made no > difference. One of the missing polygons is completely contained by the > selected feature in bnd_buf, but other features that are also completely > contained have been selected. The resultant table also shows (in QGIS) > polygons where there were no evc polygons. > > I am at a loss to explain what is going on nor how to correct it. > > Thanks in advance, > > Craig Feuerhedt > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users > > _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users ----------------------------------------- The substance of this message, including any attachments, may be confidential, legally privileged and/or exempt from disclosure pursuant to Massachusetts law. It is intended solely for the addressee. If you received this in error, please contact the sender and delete the material from any computer. _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
