Performs a Kolmogorov-Smirnov (K-S) 2-sample test. The K-S test is a non-parametric test for a difference between two empirical distributions or between an empirical distribution and a reference distribution.
A TestRes with the K-S D value and a P value for the null that FPrime is distributed identically to F against the alternative that it isn't. This implementation uses a signed D value to indicate the direction of the difference between distributions. To get the D value used in standard notation, simply take the absolute value of this D value.
Exact calculation not implemented. Uses asymptotic approximation.