Different random shuffles generated when compiled with gdc than with dmd

Andrew Brown via Digitalmars-d-learn digitalmars-d-learn at puremagic.com
Fri May 30 08:20:34 PDT 2014


I'd like it to be predictable given the seed, right now it's 
predictable given the seed and the compiler. Is this a bug, 
shouldn't the random number process be completely defined in the 
language?

I'm not trying to misuse it like the PHP crowd :) It's for a 
piece of scientific software: I'm hoping people will test the 
significance of their results with a stochastic process, and for 
reproducibility we need to allow other people to recreate their 
analysis exactly (hence the seed). For my purposes I don't need 
truly random, I just need it not to repeat too quickly.

Thanks

Andrew

On Friday, 30 May 2014 at 14:09:20 UTC, Wanderer wrote:
> I must note if the sequence is predictable, it's not random 
> anymore, it's pseudo-random at most.
>
> Also, if anyone interested, PHP had such way to generate 
> predictable sequences in the past, but after it was horribly 
> misused by various people for crypto keys/password generation 
> purposes, they have forbidden it completely, so only 
> non-predictable sequences in PHP from now on. Maybe, just 
> maybe, it makes sense not to stand on the same rack twice.



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