Hello,
I’ve just released daru (Data Analysis in RUby -
GitHub - SciRuby/daru: Data Analysis in RUby), a comprehensive data analysis,
manipulation and plotting library for ruby.
It is now completely compatible with statsample
(GitHub - SciRuby/statsample: A suite for basic and advanced statistics on Ruby.) and can thus can perform many
varied statistical computations and even plot them pretty.
You can see a preview of the API yourself in the notebooks section
(GitHub - SciRuby/daru: Data Analysis in RUby).
Do check it out and give it a shot! Any feedback is welcome 
Regards,
Sameer Deshmukh