[postgis-users] Problem with functions contains

[Martin Davis]

Please do... I'm curious!

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 8:53 AM
> To: PostGIS Users Discussion
> Subject: Re: [postgis-users] Problem with functions contains
> 
> 
> 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.
> > > 
> > > 
> > > 
> > > 
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> > > 
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