[R-sig-Geo] Ideas on qualifying urban shapes: linear / circular / star

[Barry Rowlingson]

On Fri, Sep 30, 2011 at 10:21 AM, Mathieu Rajerison
<mathieu.rajerison at gmail.com> wrote:
> Hello list,
>
>
> I have determined major urban areas.
>
> This is just a post to get ideas from R-users on how to qualify urban
> shapes.
>
> The data can either be binary raster (urban/ not urban), either vector.
>
> 1) Some urban areas follow linear infrastructures, thus are linear
> 2) Some other diverge equally from a central heart, and are circular.
> 3) Some are a mix and are like stars.
>
> The idea would be to get an index that give for each area, the probability
> of belonging to each of these three classes. Like a 3-column data frame
>
> I wondered if packages already existed, or statistical methods for this
> purpose. Notably, I think that topographic derivatives derived from
> smoothed/unsmoothed binary data like aspect, could be used to qualify these
> shapes (?)
>
> Thanks for any idea or exchange on the subject!

 Sounds like shape analysis or morphometrics. There's package:shape
that might help. Sometimes these techniques depend on landmarks though
(like the locations of eyes, noses, and ears on faces) and probably
won't be any use on vector or raster datasets.

http://en.wikipedia.org/wiki/Morphometrics

Barry