  Nondominated sorting arranges a set of points in Euclidean space into layers
by repeatedly removing the coordinatewise minimal elements. It was recently
shown that nondominated sorting of random points has a Hamilton-Jacobi equation
continuum limit. The obvious numerical scheme for this PDE has a slow
convergence rate of O(h^1/n) for a grid of spacing h>0 in dimension n. In this
paper, we introduce two new numerical schemes that have formal rates of O(h)
and we prove the usual O(h^1/2) theoretical rates. We also present the results
of numerical simulations illustrating the difference between the formal and
theoretical rates.
