  A new O(nlog(n)) algorithm is presented for performing Delaunay triangulation
of sets of 2D points. The novel component of the algorithm is a radially
propagating \emph{sweep-hull} (sequentially created from the radially sorted
set of 2D points, giving a non-overlapping triangulation), paired with a final
triangle flipping step to give the Delaunay triangluation.
  In empirical tests the algorithm runs in approximately half the time of
q-hull for 2D Delaunay triangulation on randomly generated point sets.
