$r = $x * $y ** (1 - rand 2);

[download]

update:

Or if you want to reduce the variance: 

$r = $x * $y ** ((1 - rand 2) ** $n)

[download]
where $n is an odd integer bigger than one.

In reply to Re: custom random number generator by salva
in thread custom random number generator by Anonymous Monk

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