From: David Alan Black <blackdav@...>
Date: 2004-03-07T03:57:00+09:00
Subject: Re: random range

Hi --

On Sun, 7 Mar 2004, Joel VanderWerf wrote:

> 
> 
> David A. Black wrote:
> > Hi --
> >
> > On Sun, 7 Mar 2004, Joel VanderWerf wrote:
> >
> >
> >>Hal Fulton wrote:
> >>
> >>>Someone suggested allowing not just rand(Fixnum) and rand(Range)
> >>>but in general rand(Enumerable).
> >>
> >>Would be tricky for general Enumerables...
> >>
> >>   class Seq
> >>     include Enumerable
> >>     def each
> >>       i = 0
> >>       loop do
> >>         yield i
> >>         i += 1
> >>       end
> >>     end
> >>   end
> >
> >
> > I'm not quite following (?) -- I think the original idea was
> > something like:
> >
> >   module Enumerable
> >     def rand
> >       to_a[Kernel.rand(size)]
> >     end
> >   end
> 
> Wouldn't size be infinite in this case?
> 
> Now, if you wanted a non-uniform random distribution, it would be
> possible. But how do you uniformly choose from an infinite set?

Right -- I now see what you mean.  I had Array tunnel-vision.  


David

-- 
David Alan Black
Associate Professor
Department of Communication
Seton Hall University

blackdav@shu.edu
http://pirate.shu.edu/~blackdav