[postgis-users] Roeck test

[Martin Davis]

This page has a nice write-up of three different algorithms.  Go Paul!

http://www.personal.kent.edu/~rmuhamma/Compgeometry/MyCG/CG-Applets/Center/centercli.htm

Paul Ramsey wrote:
> Wouldn't the ratio of area to perimeter be a similar metric? Also,
> wouldn't it be easier to just stop letting politicians draw their own
> boundaries? :)
>
> I wonder what the algorithm for minimum enclosing circle is...
>
> (Short answer, no, because we don't have a min-circle routine.)
>
> P.
>
> On Fri, Oct 24, 2008 at 8:59 AM, Lee Meilleur <lee.meilleur at gis.leg.mn> wrote:
>   
>> Has anyone calculated the Roeck test using PostGIS?  This is an area based measure that computes the ratio of the area of a polygon to the area of the minimum enclosing circle for the polygon.  It's used to measure compactness of districts for redistricting applications, basically a way to test for gerrymandering.  Thanks.
>>
>> Lee Meilleur
>> LCC-GIS Office
>> Minnesota Legislature
>> 100 Rev. Dr. MLK Jr Blvd.
>> 55 State Office Building
>> St. Paul, MN 55155
>> 651.296.0098  Fax: 651.297.3697
>> lee.meilleur at gis.leg.mn
>> http://www.gis.leg.mn
>>
>>
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-- 
Martin Davis
Senior Technical Architect
Refractions Research, Inc.
(250) 383-3022