non/spire — pull request #327 by non (2014-11-21 02:04:00+00:00)
Title: Improve Gaussian[A] and add Exponential[A].

This commit hooks up the ziggurat algorithm we have for generating
fast normally-distributed Double values, making Gaussian[A] a lot
faster. It also introduces Exponential[A], which also uses the
ziggurat method (and only works for Float/Double currently).

Review by @tixxit and/or @dusank