python & mathematical methods of picking numbers at random

Paul Rubin http
Thu Jan 15 21:26:33 CET 2004


Bart Nessux <bart_nessux at hotmail.com> writes:
> I am using method 'a' below to pick 25 names from a pool of 225. A
> co-worker is using method 'b' by running it 25 times and throwing out
> the winning name (names are associated with numbers) after each run
> and then re-counting the list and doing it all over again.
> 
> My boss thinks that 'b' is somehow less fair than 'a',

Both are the same, as you can see by calculating the probability of
any given name being selected.  What is the application, and the
computer environment?  You may also need to worry about correlations
in the underlying Mersenne Twister PRNG.  If the application is
something where randomness is very important (you're picking winners
for a big lottery or something) then you should use a better RNG.



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