From: William James <w_a_x_man@...>
Date: 2009-02-11T16:38:54+09:00
Subject: Re: Ruby vs Perl performance

William James wrote:

> Reid Thompson wrote:
> 
> > Reid Thompson wrote:
> > > 
> > > Ruby Elapsed 0.045477
> > > 
> > > 
> > #!/usr/local/bin/ruby
> > 
> > require 'rubygems'
> > require 'inline'
> > 
> > BAILOUT = 16
> > MAX_ITERATIONS = 1000
> > 
> > class Mandelbrot
> > 
> >      def initialize
> >          puts "Rendering"
> >          for y in -39...39 do
> >              puts
> >              for x in -39...39 do
> >                  i = iterate(x/40.0,y/40.0)
> >                  if (i == 0)
> >                      print "*"
> >                  else
> >                      print " "
> >                  end
> >              end
> >          end
> >      end
> > 
> >      inline do |builder|
> >          builder.c "
> >          int iterate (double x, double y)
> >          {
> >              int BAILOUT = 16;
> >              int MAX_ITERATIONS = 1000;
> >              double cr = y-0.5;
> >              double ci = x;
> >              double zi = 0.0;
> >              double zr = 0.0;
> >              double zr2 = 0.0;
> >              double zi2 = 0.0;
> >              int i = 0;
> >              double temp = 0.0;
> > 
> >              while (1)
> >              {
> >                 i += 1;
> >                 temp = zr * zi;
> >                 zr2 = zr * zr;
> >                 zi2 = zi * zi;
> >                 zr = zr2 - zi2 + cr;
> >                 zi = temp + temp + ci;
> > 
> >                 if ( zi2 + zr2 > BAILOUT)
> >                 {
> >                     return i;
> >                 }
> >                 if ( i > MAX_ITERATIONS)
> >                 {
> >                     return 0;
> >                 }
> >              }
> >          }"
> >      end
> 
> > 
> > end
> > 
> > 
> > time = Time.now
> > Mandelbrot.new
> > puts
> > puts "Ruby Elapsed %f" % (Time.now - time)
> 
> 
> Using the functional language F#:
> 
> 0.0400575999999999 on my laptop with 2GHz Pentium.
> 
> let bailout = 16.0
> let max_iterations = 1000
> 
> 
> let iterate x y =
>   let cr = y - 0.5  and
>       ci = x  and
>       zi = 0.0  and
>       zr = 0.0  in
>   let rec loop zi zr i =
>     if i > max_iterations then
>       0
>     else
>       let temp = zr * zi  and
>         zr2 = zr * zr  and
>         zi2 = zi * zi  in
>       if zi2 + zr2 > bailout then
>         i
>       else
>         loop (temp + temp + ci) (zr2 - zi2 + cr) (i + 1)
>   in
>   loop zi zr 1
> 
> let mandelbrot () =
>   for y = -39 to 38 do
>     print_endline "";
>     for x = -39 to 38 do
>       let i = iterate
>         (float x / 40.0) (float y / 40.0) in
>       System.Console.Write( ( if 0 = i then "*" else " " ) )
>     done
>   done
> 
> 
> let start_time = Sys.time ()
> let _ = mandelbrot ();
> print_endline "";
> System.Console.Write (Sys.time () - start_time)

Using the built-in type complex makes the program shorter but
slower.

open Math.Complex;

let max_iterations = 1000

let iterate cmp =
  let rec loop z i =
    if i > max_iterations then
      0
    else
      if magnitude z >= 2.0 then
        i
      else
        loop (z * z + cmp) (i + 1)
  in
  loop zero 1

let mandelbrot () =
  for y = -39 to 38 do
    print_endline "";
    for x = -39 to 38 do
      let i = iterate
        (complex ((float y / 40.0) - 0.5) (float x / 40.0))  in
      System.Console.Write( ( if 0 = i then "*" else " " ) )
    done
  done


let start_time = Sys.time ()
let _ = mandelbrot ();
print_endline "";
System.Console.Write (Sys.time () - start_time)