[R-sig-Geo] GRASS with R and distances between polygon edges

[Duncan Golicher]

White.Denis at epamail.epa.gov wrote:

> Or, write a program/function
>to do the search:  for each polygon, find the minimum distance between
>all of its vertices and all of the vertices of each other polygon.
>  
>
I thought of that, but was too lazy to start doing it.

>However, this algorithm does not work well with two polygons like this:
>
>|---------------------|
>|                     |
>|---------------------|
>
>           /\
>          /  \
>         /____\
>  
>
Indeed.

>A buffering approach would do better.
>
>Denis
>
>  
>
Thanks for this Dennis.  I found morphology in adehabitat does what we 
needed through erosion or dilation. Good to know that there isn't 
another simple way that we overlooked.

Duncan

-- 
Dr Duncan Golicher
Ecologia y Sistematica Terrestre
Conservación de la Biodiversidad
El Colegio de la Frontera Sur
San Cristobal de Las Casas, 
Chiapas, Mexico

Email: dgoliche at sclc.ecosur.mx 

Tel: 967 674 9000 ext 1310
Fax: 967 678 2322

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