[GRASSLIST:3095] Re: GRASSLIST digest 1338

Michael Barton michael.barton at asu.edu
Mon Apr 5 02:16:45 EDT 2004


On Sunday, April 4, 2004, at 10:01  PM, Multiple recipients of list 
wrote:

> From: "Colin Nielsen" <nielsen at myrealbox.com>
> Date: Sun Apr 4, 2004  10:05:18  AM America/Phoenix
> To: GRASSLIST at baylor.edu
> Subject: [GRASSLIST:3091] Xtent Modelling (wieghted Thieseen)
>
>
> Does anyone know of a way to rank sites so that the theissen polygons 
> are larger around higher ranked/weighted sites? I don't see any 
> weighting/ranking option in the s.voronoi module. Any ideas?
>
> -Colin
>

This is not how Thiessen polygons work. They simply divide up space by 
evenly dividing the distances between points. What you want to do is 
interesting, but different. And I'm not sure it would work since the 
polygon vertices are tied to the distances between a point and all the 
nearest surrounding points.

v.bubble creates circles around points with a radius proportionate to 
the values of a specified variable (e.g., a weighting variable). The 
s.territory module also might do what you want. Alternatively, creating 
a surface (e.g., with s.surf.rst) using the weighting varible as the 
z-value might also serve your purpose.

Michael Barton




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