Greg,
Hey everyone! I have some computations that satisfy statistical properties which I would like to test --- that is, the result of the computation is non-deterministic, but I want to check that it is sampling the distribution that it should be sampling. Is anyone aware of a Haskell library out there that does anything like this?
to do some stochastic testing (in my case, generate test cases from
I don't know of a library, but here are a couple of ideas/pointers: I wanted to do something vaguely similar in the realm of real-time hardware testing. I used QuickCheck (QC) <http://hackage.haskell.org/package/QuickCheck the reals satisfying somewhat complex constraints), and I have a small patch to the QC library to make this possible. I have a short '09 Haskell Symposium paper about it (probably Sec. 5 is the most interesting). The paper and patch are here: <http://www.cs.indiana.edu/~lepike/pub_pages/qc-biphase.html
.
One caveat though is that I didn't check that the tests generated by QC satisfied any particular distribution---I was assuming it is roughly uniformly distributed. Also, I didn't investigate how to generate other distributions, but I don't think that'd be too hard. FYI, Bryan O'Sullivan has a statistics library <http://hackage.haskell.org/package/statistics
, which I plan to use myself soon!
I'm personally interested in how things turn out for you---please keep me posted. Lee