[postgis-users] Amoeba Hulls

[Stephen Woodbridge]

Do any of these sound like it would be close to what you are looking for:

http://repositories.cdlib.org/postprints/31/
http://www.cnr.berkeley.edu/~getz/Reprints04/Getz&WilmersEcoG_SF_04.pdf
http://mathforum.org/library/topics/convex_g/

What was the other software that generated the contour? You might be 
able to find out more about that algorithm by reading up on the software.

This kind of sounds like some kind of combination of a kernel density 
plot then extracting the 80% contour polygon for the density plot.

-Steve W.

Paul Ramsey wrote:
> William,
> 
> It doesn't look like this is a standard algorithm, but more likely a 
> particular empirical technique provided by the particular software you 
> were using.  So substituting some other technique might yield a 
> different shape entirely... do any of the techniques mentioned here 
> <http://www.geospatial-online.com/geospatialsolutions/article/articleDetail.jsp?id=1348> 
> sound like what was done to your data?
> 
> Paul
> 
> William Andersen wrote:
>>
>> I'm fairly new to postgis, and working to automate a number of
>> processes.
>>
>> We are trying to compute market area polygons that look like the
>> attached image. These were created by some older software.
>>
>>
>> They are referred to as Amoeba Hulls, and they contain 80% of a
>> store's customers. However I can't find any solid documentation that
>> would allow me to reproduce them.
>>
>> Does anyone have any ideas how these shapes are created or an
>> alternate name that I might be able to google? Additionally, we may
>> be in a position to finance the development of this feature.
>>
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