NArray is an Numerical N-dimensional Array class. Supported element types are
1/2/4-byte Integer, single/double-precision Real/Complex, and Ruby Object. This
extension library incorporates fast calculation and easy manipulation of large
numerical arrays into the Ruby language. NArray has features similar to NumPy,
but NArray has vector and matrix subclasses.

WWW: http://rubygems.org/gems/narray/