As promised in a couple of CPAN RT tickets from a while ago, the Stats::Descriptive::Full methods can be made faster for common use cases.
This involves shifting some of the method calculations out of add_data, using a couple of List::Util and List::MoreUtils subs, and generally reducing the amount of processing done.
These changes are all based on code profiling I did a few months ago, and they result in substantial differences when many thousands of stats objects are created and populated.
I've used a four-space indent in the changes, and am happy to convert the rest of the file if you want. The parentheses are also mixed at the moment, so I can standardise that as well.