gamma
gamma function in javascript using the lanczos approximation for small values and the spouge approximation for larger values
example
> var gamma = require('gamma')
> gamma(5)
23.999999999999996
> gamma(1.6)
0.8935153492876909
methods
var gamma = require('gamma')
gamma(z)
Return the gamma function over z
. Complex numbers aren't supported, only reals.
gamma.log(z)
Return the natural log of the gamma function for z
.
This function is used internally by the spouge approximation to compute large values.
install
With npm do:
npm install gamma
kudos
Implementation transliterated from the python script on the wikipedia entry for the lanczos approximation.
Spouge approximation from Niggler.
license
MIT