incanter/incanter — pull request #263 by chausler (2014-08-05 23:46:51+00:00)
Title: Update median to return Double/NaN when provided an empty list

median in stats.clj currently returns 0.0 for when provided an empty list.
the median of nothing is undefined and as such should return Double/NaN.

I have updated the function for median and it's test to follow this logic.