I am not convinced. A statistical test for assessing statistical fairness is chi-square:

Well yes. Chi2 is the "standard test" in certain circles; but it needs

  1. to be implemented properly;
  2. to include Yates' (of Fisher-Yates fame) correction;
  3. to be used correctly;

I haven't investigated the particular implementation you used, but I did install it so I could run your code. A few times...

C:\test>junk123 best_shuffle : There's a >25% chance, and a <50% chance, that this dat +a is random. good_shuffle : There's a >1% chance, and a <5% chance, that this data +is random. bad_shuffle : There's a <1% chance that this data is random. C:\test>junk123 best_shuffle : There's a >75% chance, and a <90% chance, that this dat +a is random. good_shuffle : There's a >25% chance, and a <50% chance, that this dat +a is random. bad_shuffle : There's a >50% chance, and a <75% chance, that this data + is random. C:\test>junk123 best_shuffle : There's a >10% chance, and a <25% chance, that this dat +a is random. good_shuffle : There's a >5% chance, and a <10% chance, that this data + is random. bad_shuffle : There's a >50% chance, and a <75% chance, that this data + is random.

In 3 runs, it evaluates the probability that the results from (one of) the best PRNGs available, is actually random, varies between 10% and 90%, whilst that of a deliberately buggered PRNG is between 1% and 75%.

Honestly, those 3 sets of results look as good an approximation of random as I can think of.

I'll investigate whether it is the way you are using it; the implementation, or the potted interpretations it is producing later, once I've woken properly; but at first glance, I'd have to say "somethings not right".

(May be we could feed S::CS its own results and see it it judges itself random :) )


With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority". The enemy of (IT) success is complexity.
In the absence of evidence, opinion is indistinguishable from prejudice. Suck that fhit

In reply to Re^4: Shuffling CODONS by BrowserUk
in thread Shuffling CODONS by WouterVG

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