jstat/jstat — pull request #28 by richarddmorey (2012-01-06 17:52:20+00:00)
Title: improved numerical stability using logs

1. Changed many distributions to work adding logs rather than
multiplying
2. Added betaln() function, which uses gammaln(); betafn() now uses
betaln()
3. Added combinationln() (mostly for stability with binomial pdf)