[R-sig-Geo] help tp select points of border with spatstat

[Georg Ruß]

On 10/02/11 21:56:02, gianni lavaredo wrote:
> I have a points shapefile with wave shape. I wish to select only the border
> points to create a border owin with the same wave shape. I tryed to use
> convex.hull but the final shape is not the same. Some researchers have some
> suggestions?

I once had a similar issue when I wanted to create a hull (i.e. select
only the border points) for a non-convex set of points, so-to-say. I ended
up doing some approximation and also came across the alphahull package.
Maybe "ahull" in that package with a suitable "alpha" parameter can help.

Georg.
-- 
Research Assistant
Otto-von-Guericke-Universität Magdeburg
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