Distance between points and a polygon?

Thanks Rolf,

The necessary function do indeed exists in the spatstat package, but 
rather well hidden I would say.
But after looking thru the bdist.points code I came up with this example:

library(spatstat)

#Define a matrix with all the points

points<-matrix(c(1,3,3,3,6,3),3,2,byrow=T) 

#Define a matrix with the points the polyline consists of

pl<-matrix(c(1,1,4,1,4,4),3,2,byrow=T) 

#Returns the minimun distance for each point to the polyline

apply(distppll(points,cbind(pl[-nrow(pl),],pl[-1,])),1,min)
[1] 2 1 2

Cheers,

Hans Gardfjell
Ume? University, Sweden

Look at the spatstat package, available from CRAN.

The function bdist.points() does ***essentially*** what you want.  It
assumes that the points are the points of a spatial point pattern,
and that the polygon is the window though which the pattern is
observed.  But it would not be at all hard to hack this  function
into a form that would work in a more general context.

Hope this helps.

				cheers,

					Rolf Turner
					rolf at math.unb.ca

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