From: Gavin Kistner <gavin.kistner@...>
Date: 2006-11-15T02:53:17+09:00
Subject: Re: lib - generating a list of random number

From: Robert Klemme [mailto:shortcutter@googlemail.com] 
> On 14.11.2006 17:09, Josselin wrote:
> > but I don't understand very well  how to coordinate the sue 
> > of srand and rand..
> 
> I am not sure I understand you here.  What does "sue" mean here?

I think Josselin meant "use".

> What about this?
> 
>  >> def rand_seq(count, min, max)
>  >>   (1..count).map { rand(max-min) + min }
>  >> end
> => nil
>  >> rand_seq 10, -5, 5
> => [2, -4, -2, -1, -3, 1, 1, 1, -3, 0]

I think you have a fencepost error there...
  irb(main):017:0> r = rand_seq( 1_000_000, -10, 10 )
  irb(main):018:0> r.min
  => -10
  irb(main):019:0> r.max
  => 9
...though it depends if the OP wanted min/max to be inclusive or
exclusive.

Also, it depends on if the OP wanted integers only or floats. If
floating point numbers are desired, here's an alternative:

  def rand_seq(count, min, max)
    (1..count).map { rand * (max-min) + min }
  end

  r = rand_seq( 10_000_000, -10, 10 )
  p r.min, r.max
  #=> -9.99999704788504
  #=> 9.99999886739173

  p r[ 0..10 ]
  #=> [6.89334712606148, -3.51560170870142, 3.62144692732178,
9.29043168269461, -8.24044290511051, -6.06086914781006,
-6.78123809802907, 7.52184969087783, -2.21712322878881,
-0.845330115529201, -2.82092973043312]