Yep, this program will crawl. You can get reasonable numeric performance out of GHC, but you need to work at it. There is some advice in the GHC manual at http://www.haskell.org/ghc/docs/latest/html/users_guide/faster.html . The first thing I would do is replace your isInCircle :: (Floating a, Ord a) => (a,a) -> Bool with isInCircle :: (Double, Double) -> Bool Ben. On 26/02/2009, at 8:53 PM, haskell@kudling.de wrote:
Hi,
i have compared a C++ implementation with a Haskell implementation of the Monte Carlo Pi approximation:
http://lennart.kudling.de/haskellPi/
The Haskell version is 100 times slower and i wonder whether i do something obvious wrong.
Profiling says that the majority of the time is spend in "main". But i have no idea where.
Can someone give me a hint?
Thanks, Lenny