Move choose.

Statistics/Distribution/Binomial.hs

@@ -27,7 +27,7 @@ import Control.Exception (assert)
 import Data.Array.Vector
 import Data.Typeable (Typeable)
 import qualified Statistics.Distribution as D
-import Statistics.Function (choose)
+import Statistics.Math (choose)
 
 -- | The binomial distribution.
 data BinomialDistribution = BD {

Statistics/Function.hs

@@ -12,8 +12,7 @@
 
 module Statistics.Function
     (
-      choose
-    , minMax
+      minMax
     , sort
     , partialSort
     ) where
@@ -45,17 +44,3 @@ minMax = fini . foldlU go (MM (1/0) (-1/0))
     go (MM lo hi) k = MM (min lo k) (max hi k)
     fini (MM lo hi) = lo :*: hi
 {-# INLINE minMax #-}
-
--- | The binomial coefficient.
---
--- > 7 `choose` 3 == 35
-choose :: Int -> Int -> Int
-n `choose` k
-    | k > n = 0
-    | otherwise = ceiling . foldlU go 1 . enumFromToU 1 $ k'
-    where go a i = a * (nk + j) / j
-              where j = fromIntegral i :: Double
-          k' | k > n `div` 2 = n - k
-             | otherwise     = k
-          nk = fromIntegral (n - k')
-{-# INLINE choose #-}