From: Jim Freeze <jim@...>
Date: 2005-05-11T21:11:53+09:00
Subject: Re: ruby vs. java?

* Jim Freeze <jim@freeze.org> [2005-05-11 20:59:42 +0900]:

Let me point out one other thing. If you start with
   f = 1.0

instead of 
   f = 1

that is, floating pt math instead of integer math, you get:
  % ruby fac 7500
  0.03094
  0.038541
  0.068006
  % ruby fac 17500
  0.066106
  0.075447
  0.128814
  % ruby fac 27500
  0.10868
  0.113806
  0.198435

>   % ruby fac 7500
>   0.498884
>   0.337408
>   0.283017  # this is faster than #2
>   % ruby fac 17500
>   2.375539
>   2.075047
>   2.111601  # looks like a GC happened. Used to be faster.
>   % ruby fac 27500
>   5.997851
>   5.749802
>   5.797634
> 
>   % cat fac
>   def fac1( n )
>    f = 1
>    (1..n).each { |x| f *= x }
>    return f
>   end
> 
>   def fac2( n )
>    f = 1
>    (1..n).each { |x| f *= x }
>   end
> 
>   def fac3( n )
>    (1..n).inject(1) { |f,x| f * x }
>   end
> 
>   start = Time.now
>   fac1( ARGV[0].to_i )
>   puts Time.now - start
> 
>   start = Time.now
>   fac2( ARGV[0].to_i )
>   puts Time.now - start
> 
>   start = Time.now
>   fac3( ARGV[0].to_i )
>   puts Time.now - start
> 
> -- 
> Jim Freeze

-- 
Jim Freeze
Ruby: I can explain it to ya but I can't understand it fer ya.