ratistics

https://github.com/jdantonio/ratistics

Ratistics is a purely functional library that provides basic statistics functions to Ruby programs. It is intended for small data sets only. This gem was designed for simplicity. Ratistics functions operate any any enumerable object and support block syntax for accessing complex data. This makes it possible to perform statistical computations on a wide range of collections, including ActiveRecord record sets. Ratistics is pronounced *ra-TIS-tics*. Just like "statistics" but with an 'R'