Recently I added a vector strength function to scipy.  I was interested in also adding some tests of circular statistics, which scipy currently lacks, and noticed there is already a circmean, circvar, and circstd functions.  Matlab and R both have circular statistics toolboxes.

I don't think this is something that would qualify for an entirely different namespace, but what about  moving "vector_strength" to scipy.stats and having a separate section for circular statistics in the scipy.stats documentation?  Then we might be able to add some more circular statistics functions there.