[postgis-users] Intersection problems

[Sean M. Montague]

Hi Markus,

I've included images showing the areas that are causing the problem.
I've discovered a second potential bug also.  I'm using php, and have
cleaned up the files to just show the issues at hand.  The first one,
which I described yesterday, you'll need to right click on the SVG and
you'll see where I printed something to show the select statement
failed.  The second issue actually displays the SVG, except that it
leaves a county to the west out.  The bb I'm using to clip the data is
based on the extents of Devnver county, which means Jefferson county, to
the west, gets intersected, but the bb "pinches" it on the western
boundary of Denver.  I included the images, since they explain it
better.  The result is that JeffCo is left out.  Thanks for looking into
it.

Sean

-----Original Message-----
From: postgis-users-bounces at postgis.refractions.net
[mailto:postgis-users-bounces at postgis.refractions.net] On Behalf Of
Markus Schaber
Sent: Tuesday, March 08, 2005 7:03 AM
To: PostGIS Users Discussion
Subject: Re: [postgis-users] Intersection problems

Hi, Sean,

Sean M. Montague schrieb:
> I posted a few days ago about some intersection problems I was having,
> and speculated that it may be doughnut poly problems.  Further
> investigation shows that the doughnuts are not necessarily the
problem.
> It appears that if the bb representing what I want to intersect splits
a
> poly with a doughnut hole in it, postgreSQL will not even execute the
> SQL statement if the doughnut hole is intersected also.  It is
difficult
> to explain, so I have exported a jpeg showing the poly and the bb
> representing what I am trying to export.  If it'll help, let me know
and
> I will send the jpeg.  Thank you.

Please send it. Can you also send us WKT or HexWKB rep of those two
geometries?

Markus

-- 
Markus Schaber | Logical Tracking&Tracing International AG
Dipl. Inf.     | Software Development GIS

Fight against software patents in EU! www.ffii.org
www.nosoftwarepatents.org
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