mwc-probability

commit aaeb8f599c1aa4c70c2971244ef4edd63e779344
parent 85e50c05844677201ae38e4ea66da2ffb306c15a
Author: Jared Tobin <jared@jtobin.ca>
Date:   Fri, 10 Apr 2015 14:18:58 +1200

Add poisson generator.

Diffstat:
M
mwc-probability.cabal
 | 
2
+-
M
src/System/Random/MWC/Probability.hs
 | 
7
+++++++

2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/mwc-probability.cabal b/mwc-probability.cabal
@@ -1,5 +1,5 @@
 name:                mwc-probability
-version:             0.3.1.0
+version:             0.3.2.0
 homepage:            http://github.com/jtobin/mwc-probability
 license:             MIT
 license-file:        LICENSE
diff --git a/src/System/Random/MWC/Probability.hs b/src/System/Random/MWC/Probability.hs
@@ -21,6 +21,7 @@ module System.Random.MWC.Probability (
   , multinomial
   , t
   , isoGauss
+  , poisson
   ) where
 
 import Control.Applicative
@@ -31,6 +32,7 @@ import Data.List (findIndex)
 import System.Random.MWC as MWC hiding (uniform, uniformR)
 import qualified System.Random.MWC as QMWC
 import qualified System.Random.MWC.Distributions as MWC.Dist
+import System.Random.MWC.CondensedTable
 
 newtype Prob m a = Prob { sample :: Gen (PrimState m) -> m a }
 
@@ -142,3 +144,8 @@ isoGauss :: PrimMonad m => [Double] -> Double -> Prob m [Double]
 isoGauss ms sd = mapM (\m -> normal m sd) ms
 {-# INLINE isoGauss #-}
 
+poisson :: PrimMonad m => Double -> Prob m Int
+poisson l = Prob $ genFromTable table where
+  table = tablePoisson l
+{-# INLINE poisson #-}
+