In article <MPG.12f91c174956d2d89899fc@news.frii.com>, davidf@dfanning.com (David Fanning) wrote: > Anyway, the easiest way to get a perimeter, I think is to > use the Triangulate function. > > Cheers, I think that TRIANGULATE returns the convex hull of a set of points. If the boundary of the region is concave, the perimeter is different from the perimeter of the convex hull. Ken Bowman