[postgis-users] Problem with functions contains

[strk at refractions.net]

He submitted HEXEWWB, I will send you shapefiles
if you want to take a look.

--strk;

On Wed, Oct 05, 2005 at 08:50:33AM -0700, Martin Davis wrote:
> It's quite possible this is just a rendering bug.  If that's the only
> indication of a "bug in contains", then I would suspect the rendering
> rather than the function itself.
> 
> The only real way to test this is to find the vertex or line segment
> which lies outside the containing polygon. How about submitting the WKT?
> (Not perfectly accurate I know, but at least a start)
> 
> Martin Davis, Senior Technical Architect
> Vivid Solutions Inc.      www.vividsolutions.com
> Suite #1A-2328 Government Street Victoria, B.C. V8T 5G5
> Phone: (250) 385 6040 - Local 308 Fax: (250) 385 6046
> 
> 
> > -----Original Message-----
> > From: postgis-users-bounces at postgis.refractions.net 
> > [mailto:postgis-users-bounces at postgis.refractions.net] On 
> > Behalf Of strk at refractions.net
> > Sent: October 5, 2005 5:40 AM
> > To: postgis-users at postgis.refractions.net
> > Subject: Re: [postgis-users] Problem with functions contains
> > 
> > 
> > I get the same results, but I can't "visually" see the 
> > non-containment. I tried using qgis, but no displacement is 
> > shown between the two boundaries until I zoom *really close* 
> > obtaining a rendering bug instead. Can it be JUMP gets 
> > confused as well by too-small values ?
> > 
> > --strk;
> > 
> > On Tue, Oct 04, 2005 at 06:09:57PM -0300, Miguel de la Fuente wrote:
> > > strk: I' have the following problem, when I use the 
> > function contains 
> > > it returns true when the polygons is not totally contains. I have 
> > > applied snaptogrid in my geometry column. I did the following :
> > > update table1 set new_geom=snaptogrid(the_geom,1e-2)
> > > update table2 set new_geom=snaptogrid(the_geom,1e-2))
> > > When I use the function contains()
> > >  select
> > > b.*
> > > from table2 b, table1 a
> > > where contains (b.new_geom,a.new_geom)
> > > it returns true,but I see visually that b not contains completely a.
> > >  I don't understand why??
> > >   I attach the data and a image showing the problem.
> > >  Thanks.
> > 
> > 
> > 
> > 
> > > _______________________________________________
> > > postgis-users mailing list postgis-users at postgis.refractions.net
> > > http://postgis.refractions.net/mailman/listinfo/postgis-users
> > 
> > _______________________________________________
> > postgis-users mailing list postgis-users at postgis.refractions.net
> > http://postgis.refractions.net/mailman/listinfo/postgis-users
> > 
> _______________________________________________
> postgis-users mailing list
> postgis-users at postgis.refractions.net
> http://postgis.refractions.net/mailman/listinfo/postgis-users