(gamma-random<1) ( alpha beta rnd -- n )

Vocabulary

random.private

Inputs

alpha	an object
beta	an object
rnd	an object

Outputs

n

an object

Definition

USING: kernel math math.constants math.functions random ;

IN: random.private

:: (gamma-random<1) ( alpha beta rnd -- n )
    alpha e + e / :> b 0 :> x! 0 :> p! [
        p 1.0 >
        [ rnd random-unit* x alpha 1 - ^ > ]
        [ rnd random-unit* x neg e^ > ] if
    ] [
        rnd random-unit* b * p! p 1.0 <=
        [ p 1.0 alpha / ^ ] [ b p - alpha / log neg ] if x!
    ] do while x beta * ;