It is worth noting that the median (middlemost element) of a set of numbers is the point that minimizes the sum of the differences. That is, for a set of real numbers x1, ..., xn, the value

(x1-u) + (x2-u) + ... + (xn-u)

is minimized by setting u to be the median of the set.

Using this definition, we see that if n is even, then any value in the range from xn/2 to xn/2+1 could be considered the median. Additionally, it is possible to extend the definition to cover multi-dimensional sets.