module Data.Random.Distribution.Triangular where
import Data.Random.RVar
import Data.Random.Distribution
import Data.Random.Distribution.Uniform
data Triangular a = Triangular
{ triLower :: a
, triMid :: a
, triUpper :: a
} deriving (Eq, Show)
realFloatTriangular :: (RealFloat a) => a -> a -> a -> RVar a
realFloatTriangular a b c
| a <= b && b <= c
= do
let p = (cb)/(ca)
u <- realFloatStdUniform
let d | u >= p = a
| otherwise = c
x | u >= p = (u p) / (1 p)
| otherwise = u / p
return (b ((1 sqrt x) * (bd)))
instance RealFloat a => Distribution Triangular a where
rvar (Triangular a b c) = realFloatTriangular a b c