1. A non-transitory computer readable medium storing a program for determining positional entropy of a set of N points resulting from a measurement, said program comprising the steps of: receiving coordinates for each of said N points; calculating a set of a maximum of N(N−1)/2 pairs of distances within said points; calculating local symmetry; calculating global symmetry to determine a set of occupation numbers; determining a total symmetry and an un-normalized positional entropy deficit for said points from said occupation numbers; and determining a positional entropy value of said set of N points.