geometric-random* ( p rnd -- n )

Vocabulary

random

Inputs

p	an object
rnd	an object

Outputs

n

an object

Definition

USING: kernel math math.functions ;

IN: random

:: geometric-random* ( p rnd -- n )
    p 0.3333333333333333 >= [
        1.0 p - :> q rnd random-unit* :> U 1 p p
        [ U over > ] [ [ 1 + ] [ q * ] [ dupd + ] tri* ] while
        2drop
    ] [
        1.0 rnd random-unit* - log 1.0 p - log /
        ceiling >integer
    ] if ;