Thorsten Froehlich <tho### [at] trfde> wrote:
> On 12.05.10 19:38, Warp wrote:
> > Thorsten Froehlich<tho### [at] trfde>  wrote:
> >> This property is shared by all software random number generators
> >> that have no hardware source of randomness.
> >
> >    No

> Yes, thank you for taking some sentence out of context, putting some random 
> words in my mouth, and then providing some pointless off-topic lecture. ROFL

  And exactly how was it taken out of context?

  The original poster had noticed (and you quoted it) that there was a
clearly distinguishable pattern between the seed and the subsequent random
numbers. In other words, when the initial seed is changed incrementally,
an obviously regular pattern emerges from the rng stream that follows.

  To that observation you responded with "the rng has been designed so, and
this is a property of *all* rngs".

  Clearly you were confusing this situation with the fact that a given seed
will always produce the same random stream, which is a completely different
matter.

  The rng used in POV-Ray was certainly not specifically designed to give
clearly distinguishable patterns in relation to successive seed values. This
is simply a side-effect of the linear congruential generator used by POV-Ray.

  Higher-quality rngs don't present such obvious patterns. You can try with
successive seed values, and such linear patterns won't emerge (at least not
as obviously). Naturally the same seed will always give the same rng stream,
but that's a completely different matter.

-- 
                                                          - Warp

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