From: seebs@... (Peter Seebach)
Date: 2007-04-30T16:46:44+09:00
Subject: Re: sorting by rand?

In message <4635AB25.9050809@gmail.com>, Dan Zwell writes:
>You're right. I guess I'm just inclined to discount a such a small 
>difference in orderings. And the difference in our benchmarks may have 
>been due to the fact that I'm using a different algorithm (for each 
>element i, swap i with an element from i...end).

Hmm.  I don't *think* that makes a difference, although I'm not sure.
It may affect the results.

>Or perhaps because I 
>have more method calls, as I made a method Array#randomize! (that calls 
>Array#swap! n times)

That might well do it; method lookup is comparatively expensive, I
think.

... Of course, the entire thing is probably silly, in that I doubt most
programs spend much time unsorting arrays.  I was mostly just curious
about the question of what happens if you try to provide an un-fixed
sort key.  For sort_by, they're cached; sort { rand <=> rand } might
be unpredictable, though.

-s