I would like to convert a point shapefile into a polygon shapefile
containing an alpha hull of the points.  I've imported the point shapefile
and calculated the desired alpha hull:

#######################################
require(spdep)
require(alphahull)

ccPoints=readShapeSpatial('myshapefile')
a=5000

x.coords <- coordinates(ccPoints)
x.ah <- ahull(x.coords[,1], x.coords[,2], alpha=a)

# plot the concave alpha hull:
# plot(x.ah,col='purple',add=T,asp=1,cex=0, pch=4)
# looks good...

# now, would like to export alpha hull as a shapefile with a single polygon
# something like this:
# write.shp(x.ah, file = 'ahull-shapefile.shp')
#######################################

How do I output a polygon shapefile containing the alpha hull?

Many thanks, Kevin

	[[alternative HTML version deleted]]

