random uses

#define oneUp31Bit      (4.656612875245796924105750827168e-10)
val = (((val* 214013 + 2531011) >> 1) & 0x7fffffff) * oneUp31Bit


rand uses one of two algorithms -- selectable

Original is
#define RNDMUL  15625
           rand *= rndmul;
           rand += 1

New is
f(z) = (16807 * z) mod (2 ** 31 - 1)
  *  Based on "Random Number Generators: Good Ones Are Hard to Find",
  *  S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
  *  and "Two Fast Implementations of the 'Minimal Standard' Random
  *  Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), p. 87-88

I believe rand with new algorithm is high quality

On some machines you can get true random with urandom

==John
Quoting mskala@ansuz.sooke.bc.ca:

> On Mon, 17 Feb 2014, Paul Batchelor wrote:
>> random* lets you specify specific max/min ranges.
>>
>> rand* does values between 0 and 1
>
> The rand* opcodes also seem to allow adjusting the bounds using the
> amplitude and offset arguments.  But that's what I meant by syntax
> differences.  Are there any more substantive differences, for instance in
> the PRNG algorithms used?
>
> --
> Matthew Skala
> mskala@ansuz.sooke.bc.ca                 People before principles.
> http://ansuz.sooke.bc.ca/
>
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