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Yes, I guess that what I meant too, you just formulate it better, in a
more general way. I find this interesting, as I have experimented with
weighted Voronoi polygons, but only in vector format. There is a
complete book on that methodolgy: Atsuyuki Okabe, Barry Boots, Kokochi
Sugihara, Sung Nok Chiu: Spatial Tesselations. Concepts and
Applications of Voronoi Diagrams. Wiley, Chichester 2000. It's really
fascinating to see how much you can do with this technology, not only
in theory but also in practice. Of course, the vector based algorithms
are hard to implement and can be very resource hungry. A lot of them
are already available however: just Google on "weighted voronoi". As
always, a raster based approach could be not only more efficient, but
also conceptually more general. There is an ArcGIS extension available
that does exactly this: see
<a class="moz-txt-link-freetext" href="http://portal.acm.org/citation.cfm?id=1332465">http://portal.acm.org/citation.cfm?id=1332465</a><br>
<br>
With that in mind, if the algorithm you propose would be indeed an
approximation to weighted Voronoi polygons, *and* it wouldn't be all to
hard to implement (I have no idea about that), would it make sense to
propose this as a new RFC for GRASS?<br>
<br>
Jan<br>
<br>
Glynn Clements wrote:
<blockquote
cite="mid:18837.32489.523357.871738@cerise.gclements.plus.com"
type="cite">
<pre wrap="">Jan Hartmann wrote:
</pre>
<blockquote type="cite">
<blockquote type="cite">
<pre wrap="">The problem with using r.cost is that you would need to know the cost
for each cell before you have created the polygons.
I think that the simplest accurate approach would be to modify
r.grow.distance.
</pre>
</blockquote>
<pre wrap="">Do you mean: adding a metric parameter to Euclidean, Squared, Manhattan,
and Maximum? Something like: compute on the basis of the value of
traversed cells?
</pre>
</blockquote>
<pre wrap=""><!---->
I mean scale the distance by the value of the nearest non-null cell.
</pre>
</blockquote>
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