"Phoenex" <rib### [at] sapopt> wrote:
> Try to use the MOD function to do an algorithm like Alvo and giving the same
> random numbers.
> I dont think x = sx MOD 1.0 is the same as x = sx - INT(sx)
> Thats one of many explanations why x = sx - INT(sx) algorithm is not an LCG.

Mathematically speaking, the "MOD 1.0" operation - when applied to floats - is
*exactly* what the fraction operation does.

However, there is indeed a significant difference between an LCG and your
algorithm, in that an LCG operates in the integer domain, and thus its values
can never "grow fractional digits".

To do exactly the same as your algorithm does, an LCG would have to use a
fractional s. I'm not sure whether that still fits the bill of an LCG, but at
any rate it's no longer a *classic* LCG.

> However, I made 3 tests with your "s" that follow. Also with the Diehard test
> the results are quit good with no p-values.

Um... may I ask what precisely you mean by "no p-values"?

If I'm not totally mistaken the Diehard test *gives* you p-values, no matter
what. They're the output of the test suite, and their actual values require
some degree of interpretation.

Also note that test suites don't tell you whether your numbers are really as
good as random. They just examine your random number stream for *some* types of
patterns.

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