Data.Number.Erf

Documentation

class Floating a => Erf a where

Error function related functions.

The derivative of erf is x -> 2 / sqrt pi * exp (x^2), and this uniquely determines erf by erf 0 = 0.

Minimal complete definition is erfc or normcdf.

Methods

erf :: a -> a

erfc

Arguments

:: a

-> a

erfc x = 1 - erf x

erfcx

Arguments

:: a

-> a

erfcx x = exp (x*x) * erfc x

normcdf

Arguments

:: a

-> a

normcdf x = erfc(-x  sqrt 2)  2

Instances

Erf Double

Erf Float

class Floating a => InvErf a where

Inverse error functions, e.g., inverf . erf = id and erf . inverf = id assuming the appropriate codomain for inverf. Note that the accuracy may drop radically for extreme arguments.

Methods

inverf :: a -> a

inverfc :: a -> a

invnormcdf :: a -> a

Instances

InvErf Double

InvErf Float