On Tue, 26 Jan 2010, Karl Ove Hufthammer wrote:
Dear list members
Is there an easy and preferably fast way to measure the distance from a
of (large) number of points to the nearest polygon? spDistsN1 seems to
only want to measure the distance between points.
For example, I need the distance between points at sea to the nearest
land area (as defined by for example the 'world' dataset).
It's not very important which polygon, e.g., country, the given distance
is to. It would be nice if the 'distance' from points that are inside
the polygons were zero or negative, but it's not required -- distance to
the polygon border, e.g., shoreline, would be OK.
There are methods for point to line segment distances in spatstat.
Further, for projected (planar) coordinates, this could be added to
R-Forge rgeos; for geographical coordinates Boost ggl would be needed.
Roger
--
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: roger.biv...@nhh.no
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