Htirage/Draw.hs

   1 -- | Tirages.
   2 module Htirage.Draw where
   3
   4 import Data.Bool
   5 import Prelude (Integer, Integral(..), Num(..))
   6 import Data.List (length, map)
   7
   8 import Htirage.Bits
   9 import Htirage.Combin
  10 import Htirage.Sequence
  11
  12 -- | @unorderedDraw k xs bs@ retourne 'k' choix (sans ordre ni répétition) parmi 'xs'
  13 -- déterminés par l’entropie 'bs'.
  14 unorderedDraw :: Integer -> [a] -> [Bool] -> [a]
  15 unorderedDraw k xs bs = map fromInteger (combinOfRank n k r) `permute` xs
  16         where n = toInteger (length xs)
  17               r = randomIntegerOfBits (n`nCk`k) bs
  18
  19 -- | @orderedDraw k xs bs@ retourne 'k' choix (avec ordre mais sans répétition) parmi 'xs'
  20 -- déterminés par l’entropie 'bs'.
  21 orderedDraw :: Integer -> [a] -> [Bool] -> [a]
  22 orderedDraw k xs bs = map fromInteger (sequenceOfRank n k r) `permute` xs
  23         where n = toInteger (length xs)
  24               r = randomIntegerOfBits (n`nAk`k) bs