module Statistics.Distribution.Geometric
(
GeometricDistribution
, fromSuccess
, pdSuccess
) where
import Control.Exception (assert)
import Data.Typeable (Typeable)
import qualified Statistics.Distribution as D
newtype GeometricDistribution = GD {
pdSuccess :: Double
} deriving (Eq, Read, Show, Typeable)
instance D.Distribution GeometricDistribution where
probability = probability
cumulative = cumulative
inverse = inverse
instance D.Variance GeometricDistribution where
variance (GD s) = (1 s) / (s * s)
instance D.Mean GeometricDistribution where
mean (GD s) = 1 / s
fromSuccess :: Double -> GeometricDistribution
fromSuccess x = assert (x >= 0 && x <= 1)
GD x
probability :: GeometricDistribution -> Double -> Double
probability (GD s) x = s * (1s) ** (x1)
cumulative :: GeometricDistribution -> Double -> Double
cumulative (GD s) x = 1 (1s) ** x
inverse :: GeometricDistribution -> Double -> Double
inverse (GD s) p = log (1 p) / log (1 s)