convex hull indices

[tretherington]

The convex function returns the pairs of points that make up the edges of the convex hull, but the indices for these points need correcting for us by R. It would also be useful to return just a list of the points as well as the edges.

x = c(30,70,20,50,40,70)
y = c(35,80,70,50,60,20)
p =data.frame(x,y)
hull =convex(point=p)
hull$convexhull[is.na(hull$convexhull)] = 0
hull$convexhull = hull$convexhull + 1
nodes = unique(c(hull$convexhull[,1],hull$convexhull[,2]))
plot(p)
points(p[nodes,], col="red", pch=16)

[tretherington]

This applies to the Delaunay triangulation too, so best check all functions

[pascal082]

@tretherington now fixed