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List:       postgis-users
Subject:    [postgis-users] Re: Negative buffer chokes on Alaska
From:       Sean Fulton <seanasy () gmail ! com>
Date:       2008-06-24 2:46:38
Message-ID: g3pn6d$36r$1 () ger ! gmane ! org
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Yep. ST_IsValid returns true.

	Sean

On 2008-06-23 10:02:10 -0400, "Paul Ramsey" <pramsey@cleverelephant.ca> said:

> Have you run as ST_IsValid test on it?
> 
> On Sun, Jun 22, 2008 at 7:47 PM, Sean Fulton <seanasy@gmail.com> wrote:
>> I have Census congressional district data loaded in a Postgis db. I want to
>> do a negative buffer on all of the districts. The data is in US National
>> Atlas (EPSG:2163).
>> 
>> Whenever I try to do a large (~10,000 m) buffer postgresql crashes. I
>> eventually figured out that Alaska was causing the problem. Reducing the
>> buffer gives unusual results for Alaska. A -500m buffer produces the image
>> attached (blue = buffer result, green = original data).
>> 
>> Postgis: POSTGIS="1.3.3" GEOS="3.0.0-CAPI-1.4.1" PROJ="Rel. 4.6.0, 21 Dec
>> 2007" USE_STATS
>> Original data: http://dpaste.com/58232/plain/
>> 
>> Is it a problem with the data? With Postgis?
>> 
>> Thanks in advance,
>> 
>> Sean
>> _______________________________________________
>> postgis-users mailing list
>> postgis-users@postgis.refractions.net
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