Download full size 2560 x 1600 original of by .

Tags: artwork, desktop, wallpaper, fractal, mandelbrot, 2012

I have always enjoyed fractals, and was curious if scripting languages were up to the task. I wrote a very simple Mandelbrot set generator for my test. Rather than optimizing for each language, I tried to write each program in approximately the same way in each language to make a reasonable performance comparison.

Here are the results from running on my 867 mhz Powerbook G4. Shorter is better. Please note, the following benchmarks are not scientific, and were simply done to satisfy my curiosity. Your mileage may vary.

Feel free to send me ports to any other languages. The program should print the time in seconds that elapsed at the bottom in the form of 'Elapsed %0.2f'. If you can, include instructions for building on MacOS X.

— Erik Wrenholt (erik -at- timestretch.com) 2005-09-20

LanguageTime SecondsRelative Time
C gcc-4.0.1 0.05   1.00 x
ocaml compiled 3.09.2 0.05   1.00 x
SBCL 1.0.2 0.13   2.55 x
Java 1.4.2 0.40   8.00 x
Io 20070410 Vector 1.40   28.09 x
Lua 5.1 1.50   30.00 x
ocaml bytecode 3.09.2 3.76   75.15 x
Python 2.5.1 9.99   199.80 x
Ghostscript 8.51 11.66   233.12 x
Perl 5.8.6 Optimized 12.37   247.34 x
TCL 8.4 Optimized 16.00   320.00 x
Perl 5.8.6 21.75   435.00 x
PHP 5.1.4 23.12   462.40 x
Javascript SpiderMonkey v1.6 31.06   621.27 x
Ruby 1.8.4 34.31   686.18 x
Emacs Lisp 47.25   945.00 x
Applescript 71.75   1435.00 x
Io 20070410 85.26   1705.13 x

2012-02-07 Fractal Benchmark Extended: Theo Wollenleben has added many more language ports and benchmarks!

2007-06-08 — I enabled optimization in C. 'gcc -O3 Mandelbrot.c -o Mandelbrot.'

2007-06-04 — I added a compiled OCAml version. Faster than both C and SBCL!

2007-06-02 — I updated the C version to utilize doubles instead of floats. Most scripting languages use doubles behind-the-scenes so this results in a more accurate comparision.

I updated Python to 2.5.1. Much faster!

I also began including speed relative to the fastest language.

2007-06-02 — I fixed up the Java, Ruby, Lua, Io, PHP, and Applescript versions. They were calculating one extra row and column (less than or equal to 39 rather than just less than). It turns out this didn't affect performance that much because those columns are over a low-iteration area.

I also starting running each language four times and averaging the time elapsed in order to make the results more consistent.

2007-05-28 — I added a SBCL Lisp version. Unfortunately, SBCL triggers a crash report on MacOS X every time I invoke it. SBCL's actual performance may vary slightly from the results shown.

2007-05-27 — I added a Ghostscript Postscript version.

2007-05-26 — I added an OCaml and Javascript (Using Mozilla's SpiderMonkey 1.6). I also removed the 'slow' TCL version and left the optimized one. After adding curly brackets around expressions, it increased the speed by 25 times.

2007-04-26 — I added an Applescript version.

2007-04-24 — Just for fun, I'm including optimized versions that don't change the character of the code (e.g. no loop unrolling). I received both Perl and TCL optimized versions and have included them in the benchmark. It's interesting to see how minor changes can drastically improve the performance of these scripts. If you notice something glaringly inefficient in one of the examples below, let me know.

2007-04-03 — I temporarily removed the Haskell version while I learn how to get it to print 'Elapsed <seconds>'. Anders Bergh ported the scripts on this page to D, C#. When I am able to run them from the command line, I'll add them to this page. Also pending are a Javascript, and a CL version.

Benchmark Generated on 2007-06-08 21:11:16

C gcc-4.0.1

// by Erik Wrenholt
#include <stdio.h>
#include <sys/time.h>

#define BAILOUT 16
#define MAX_ITERATIONS 1000

int mandelbrot(double x, double y)
{
	double cr = y - 0.5;
	double ci = x;
	double zi = 0.0;
	double zr = 0.0;
	int i = 0;

	while(1) {
		i ++;
		double temp = zr * zi;
		double zr2 = zr * zr;
		double zi2 = zi * zi;
		zr = zr2 - zi2 + cr;
		zi = temp + temp + ci;
		if (zi2 + zr2 > BAILOUT)
			return i;
		if (i > MAX_ITERATIONS)
			return 0;
	}
	
}

int main (int argc, const char * argv[]) {
	struct timeval aTv;
	gettimeofday(&aTv, NULL);
	long init_time = aTv.tv_sec;
	long init_usec = aTv.tv_usec;

	int x,y;
	for (y = -39; y < 39; y++) {
		printf("\n");
		for (x = -39; x < 39; x++) {
			int i = mandelbrot(x/40.0, y/40.0);
			if (i==0)
				printf("*");
			else
				printf(" ");
		}	
	}
	printf ("\n");
	
	gettimeofday(&aTv,NULL);
	double query_time = (aTv.tv_sec - init_time) + (double)(aTv.tv_usec - init_usec)/1000000.0;	
	printf ("C Elapsed %0.2f\n", query_time);
    return 0;
}

Java 1.4.2

// by Erik Wrenholt
import java.util.*;

class Mandelbrot
{  
	static int BAILOUT = 16;
	static int MAX_ITERATIONS = 1000;
	
	private static int iterate(float x, float y)
	{
		float cr = y-0.5f;
		float ci = x;
		float zi = 0.0f;
		float zr = 0.0f;
		int i = 0;
		while (true) {
			i++;
			float temp = zr * zi;
			float zr2 = zr * zr;
			float zi2 = zi * zi;
			zr = zr2 - zi2 + cr;
			zi = temp + temp + ci;
			if (zi2 + zr2 > BAILOUT)
				return i;
			if (i > MAX_ITERATIONS)
				return 0;
		}
	}

	public static void main(String args[])
	{
		Date d1 = new Date();
		int x,y;
		for (y = -39; y < 39; y++) {
			System.out.print("\n");
			for (x = -39; x < 39; x++) {
				if (iterate(x/40.0f,y/40.0f) == 0) 
					System.out.print("*");
				else
					System.out.print(" ");

			}
		}
		Date d2 = new Date();
		long diff = d2.getTime() - d1.getTime();
		System.out.println("\nJava Elapsed " + diff/1000.0f);
		
	}
}

Io 20070410 Vector

#!/usr/local/bin/io

# Vectorized by Steve Dekorte

printSet := method(
    bailout := 16
    max_iterations := 1000

    cr := Vector clone
    ci := Vector clone

    i := 0
    for(y, -39, 38,
	for(x, -39, 38,
	    cr atPut(i, y/40.0 - 0.5)
	    ci atPut(i, (x/40.0))
	    i = i + 1
	)
    )

    size := cr size

    zi := Vector clone setSize(size)
    zr := Vector clone setSize(size) 
    zr2 := Vector clone setSize(size)
    zi2 := Vector clone setSize(size)
    temp := Vector clone setSize(size)

    for(i, 1, max_iterations,
	temp copy(zr) *= zi
	
	zr2 copy(zr) square
	zi2 copy(zi) square
	
	zr copy(zr2) -= zi2 
	zr += cr
	zi copy(temp) *= 2
	zi += ci
    )

    result := zi2 + zr2

    i := 0
    for(y, -39, 38,
	writeln
	for(x, -39, 38,
	    r := result at(i) 
	    write(if( r > 0, "*", " "))
	    i = i + 1
	)
    )
)

writeln("\nIo Elapsed " .. Date secondsToRun(printSet))

Lua 5.1

#!/usr/local/bin/lua

-- By Erik Wrenholt

local BAILOUT = 16
local MAX_ITERATIONS = 1000

function iterate(x,y)

	local cr = y-0.5
	local ci = x
	local zi = 0.0
	local zr = 0.0
	local i = 0
	
	while 1 do
		i = i+1
		local temp = zr * zi
		local zr2 = zr*zr
		local zi2 = zi*zi
		zr = zr2-zi2+cr
		zi = temp+temp+ci
		if (zi2+zr2 > BAILOUT) then
			return i
		end
		
		if (i > MAX_ITERATIONS) then
			return 0
		end
	end

end

function mandelbrot()
	local t = os.time()
	for y = -39, 38 do
		for x = -39, 38 do
			if (iterate(x/40.0, y/40) == 0) then
				io.write("*")
			else
				io.write(" ")
			end
		end
		io.write("\n")
	end
	io.write(string.format("Time Elapsed %d\n", os.time() - t))
end

mandelbrot()

ocaml compiled 3.09.2

(* Courtesy of pango on #ocaml *)

let bailout = 16.
let max_iterations = 1000

let mandelbrot x y =
  let cr = y -. 0.5 in
  let ci = x in
  let zi = ref 0.0 in
  let zr = ref 0.0 in
  let i = ref 0 in
  let continue = ref true in
  let result = ref 0 in
  while !continue do
    incr i;
    let temp = !zr *. !zi in
    let zr2 = !zr *. !zr in
    let zi2 = !zi *. !zi in
    zr := zr2 -. zi2 +. cr;
    zi := temp +. temp +. ci;
    if zi2 +. zr2 > bailout then begin
      result := !i;
      continue := false;
    end
    else if !i > max_iterations then
      continue := false;
  done;
  !result

let () =
  let start_time = Unix.gettimeofday () in
  for y = -39 to 38 do
    print_newline ();
    for x = -39 to 38 do
      let i = mandelbrot (float x /. 40.) (float y /. 40.) in
      print_char (if i = 0 then '*' else ' ');
    done
  done;
  print_newline ();
  let stop_time = Unix.gettimeofday () in
  let query_time = stop_time -. start_time in
  Printf.printf "OCaml Elapsed %0.2f\n" query_time

ocaml bytecode 3.09.2

#!/opt/local/bin/ocamlrun ocaml unix.cma
(* Courtesy of pango on #ocaml *)

let bailout = 16.
let max_iterations = 1000

let mandelbrot x y =
  let cr = y -. 0.5 in
  let ci = x in
  let zi = ref 0.0 in
  let zr = ref 0.0 in
  let i = ref 0 in
  let continue = ref true in
  let result = ref 0 in
  while !continue do
    incr i;
    let temp = !zr *. !zi in
    let zr2 = !zr *. !zr in
    let zi2 = !zi *. !zi in
    zr := zr2 -. zi2 +. cr;
    zi := temp +. temp +. ci;
    if zi2 +. zr2 > bailout then begin
      result := !i;
      continue := false;
    end
    else if !i > max_iterations then
      continue := false;
  done;
  !result

let () =
  let start_time = Unix.gettimeofday () in
  for y = -39 to 38 do
    print_newline ();
    for x = -39 to 38 do
      let i = mandelbrot (float x /. 40.) (float y /. 40.) in
      print_char (if i = 0 then '*' else ' ');
    done
  done;
  print_newline ();
  let stop_time = Unix.gettimeofday () in
  let query_time = stop_time -. start_time in
  Printf.printf "OCaml Elapsed %0.2f\n" query_time

Python 2.5.1

#!/usr/local/bin/python
# by Daniel Rosengren

import sys, time
stdout = sys.stdout

BAILOUT = 16
MAX_ITERATIONS = 1000

class Iterator:
  def __init__(self):
    print 'Rendering...'
    for y in range(-39, 39):
      stdout.write('\n')
      for x in range(-39, 39):
        i = self.mandelbrot(x/40.0, y/40.0)
        
        if i == 0:
          stdout.write('*')
        else:
          stdout.write(' ')
    
  def mandelbrot(self, x, y):
    cr = y - 0.5
    ci = x
    zi = 0.0
    zr = 0.0
    i = 0

    while True:
      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

t = time.time()
Iterator()
print '\nPython Elapsed %.02f' % (time.time() - t)

Ghostscript 8.51

%!PS
%% frac.ps by Jeff Zaroyko
%% a transliteration of the program by Erik Wrenholt
%% at http://www.timestretch.com/FractalBenchmark.html
/star {(*) print } bind def
/space { ( ) print } bind def
realtime pop

/BAILOUT 16 def
/MAX_ITERATIONS 1000 def

/mandelbrot { %% mx my
    /mx exch def
    /my exch def

    /cr my 0.5 sub def
    /ci mx def
    /zi 0.0 def
    /zr 0.0 def
    /i 0 def

    {
     /i i 1 add def
     /temp zr zi mul def
     /zr2 zr zr mul def
     /zi2 zi zi mul def
     /zr zr2 zi2 sub cr add def
     /zi temp temp add ci add def
     zi2 zr2 add BAILOUT gt
	 {
	     i exit 
	 } if
     i MAX_ITERATIONS gt
	 {
	     0 exit 
	 } if
    } loop
} bind def

% main

/y -39 def
{
    y 39 lt
    {
	/y y 1 add def
	(\n) print 

	/x -39 def
	{
	    x 39 lt
	    {
		/x x 1 add def
		y 40.0 div x 40.0 div mandelbrot
		0 eq { star  } { space  } ifelse
	    } { exit } ifelse
	} loop
    } { exit }ifelse  % Done.
} loop

realtime dup log ceiling cvi string cvs
(\nTotal time Elapsed ) print print (ms\n) print
quit

Perl 5.8.6 Optimized

#!/usr/bin/perl
# Ported from C to Perl by Anders Bergh <anders1@gmail.com>
# Some Perlification by John Gabriele (4-24-2007).

use strict;
use warnings;
use Time::HiRes qw( gettimeofday );

my $BAILOUT = 16;
my $MAX_ITERATIONS = 1000;
my $begin = gettimeofday();

sub mandelbrot {
    my ( $x, $y ) = @_;

    my $cr = $y - 0.5;
    my $ci = $x;
    my ( $zi, $zr ) = ( 0.0, 0.0 );
    my $i = 0;

    my ( $temp, $zr2, $zi2 );
    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;
        }
    }
}

for ( my $y = -39; $y < 39; $y++ ) {
    print( "\n" );
    my $i;
    for ( my $x = -39; $x < 39; $x++ ) {
        $i = mandelbrot( $x / 40.0, $y / 40.0 );
        if ( $i == 0 ) {
            print q{*};
        }
        else {
            print q{ };
        }
    }
}

print "\n";
my $end = gettimeofday() - $begin;
print "Perl Elapsed $end\n";

Perl 5.8.6

#!/usr/bin/perl
# Ported from C to Perl by Anders Bergh <anders1@gmail.com>
#

$BAILOUT=16;
$MAX_ITERATIONS=1000;

$begin = time();

sub mandelbrot {
       local $x = $_[0];
       local $y = $_[1];

       local $cr = $y - 0.5;
       local $ci = $x;
       local $zi = 0.0;
       local $zr = 0.0;
       local $i = 0;

       while (1)
       {
               $i = $i + 1;
               local $temp = $zr * $zi;
               local $zr2 = $zr * $zr;
               local $zi2 = $zi * $zi;
               $zr = $zr2 - $zi2 + $cr;
               $zi = $temp + $temp + $ci;
               if ($zi2 + $zr2 > $BAILOUT)
               {
                       return $i;
               }
               if ($i > $MAX_ITERATIONS)
               {
                       return 0;
               }
       }
}

for ($y = -39; $y < 39; $y++)
{
       print("\n");
       for ($x = -39; $x < 39; $x++)
       {
               $i = mandelbrot($x/40.0, $y/40.0);
               if ($i == 0)
               {
                       print("*");
               }
               else
               {
                       print(" ");
               }
       }
}
print("\n");

$end = time() - $begin;

print "Perl Elapsed $end\n";

PHP 5.1.4

#!/usr/local/php5/bin/php
<?php
define("BAILOUT",16);
define("MAX_ITERATIONS",1000);

class Mandelbrot
{
	

	function Mandelbrot()
	{
		$d1 = microtime(1);
		for ($y = -39; $y < 39; $y++) {
			echo("\n");
			for ($x = -39; $x < 39; $x++) {
				if ($this->iterate($x/40.0,$y/40.0) == 0) 
					echo("*");
				else
					echo(" ");

			}
		}
		$d2 = microtime(1);
		$diff = $d2 - $d1;
		printf("\nPHP Elapsed %0.2f", $diff);
	}

	function iterate($x,$y)
	{
		$cr = $y-0.5;
		$ci = $x;
		$zi = 0.0;
		$zr = 0.0;
		$i = 0;
		while (true) {
			$i++;
			$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;
		}
	
	}


}

$m = new Mandelbrot();
?>

Ruby 1.8.4

#!/usr/local/bin/ruby

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

	def iterate(x,y)
		cr = y-0.5
		ci = x
		zi = 0.0
		zr = 0.0
		i = 0
		
		while(1)
			i += 1
			temp = zr * zi
			zr2 = zr * zr
			zi2 = zi * zi
			zr = zr2 - zi2 + cr
			zi = temp + temp + ci
			return i if (zi2 + zr2 > BAILOUT)
			return 0 if (i > MAX_ITERATIONS)
		end
	
	end

end

time = Time.now
Mandelbrot.new
puts
puts "Ruby Elapsed %f" % (Time.now - time)

Javascript SpiderMonkey v1.6

#!/usr/local/bin/js
/* Javascript version by Patrick Haller.*/

function mandelbrot(x, y) {
	var cr = y - 0.5;
	var ci = x;
	var zi = 0.0;
	var zr = 0.0;
	var i = 0;
	var BAILOUT = 16;
	var MAX_ITERATIONS = 1000;

	while(1) {
		i++;
		var temp = zr * zi;
		var zr2 = zr * zr;
		var zi2 = zi * zi;
		zr = zr2 - zi2 + cr;
		zi = temp + temp + ci;
		if (zi2 + zr2 > BAILOUT) {
			return i;
		}
		if (i > MAX_ITERATIONS) {
			return 0;
		}
	}
}

function mandelbrot_run() {
	var x; var y;
	output = "";
	
	var date = new Date();
	for (y = -39; y < 39; y++) {
		print(output);
		output = "";
		for (x = -39; x < 39; x++) {
			var i = mandelbrot(x/40.0, y/40.0);
			if (i==0) {
				output += "*";
			}
			else {
				output += " ";
			}
		}	
	}
	var date2 = new Date();
	output += "\nJavaScript Elapsed " + (date2.getTime() - date.getTime()) / 1000;
	print(output);
	return false;
}

mandelbrot_run();

TCL 8.4 Optimized

#!/usr/bin/tclsh

# Optimized Version by Samuel Zafrany

# Ported from C by Anders Bergh <anders1@gmail.com>
package require Tcl 8.4

set BAILOUT 16
set MAX_ITERATIONS 1000

proc mandelbrot {x y} {
       global BAILOUT
       global MAX_ITERATIONS

       set cr [expr {$y - 0.5}]
       set ci $x
       set zi 0.0
       set zr 0.0
       set i 0

       while {1} {
               incr i
               set temp [expr {$zr * $zi}]
               set zr2 [expr {$zr * $zr}]
               set zi2 [expr {$zi * $zi}]
               set zr [expr {$zr2 - $zi2 + $cr}]
               set zi [expr {$temp + $temp + $ci}]

               if {$zi2 + $zr2 > $BAILOUT} {
                       return $i
               }

               if {$i > $MAX_ITERATIONS} {
                       return 0
               }
       }
}

set begin [clock clicks -milliseconds]

for {set y -39} {$y < 39} {incr y} {
       puts ""
       for {set x -39} {$x < 39} {incr x} {
               set i [mandelbrot [expr {$x / 40.0}] [expr {$y / 40.0}]]

               if {$i == 0} {
                       puts -nonewline "*"
               } else {
                       puts -nonewline " "
               }
               flush stdout
       }
}
puts ""

set diff [expr [clock clicks -milliseconds] - $begin]
#puts "Tcl Elapsed [expr int($diff / 1000)] seconds ($diff ms)"
puts "Tcl Elapsed [expr int($diff / 1000)]"

Emacs Lisp

; By Erik Wrenholt
; emacs -l Mandelbrot.lisp -batch

(defun iterate (xx yy)
	
	(let* 
	(
		(BAILOUT 16.0)
		(MAX_ITERATIONS 1000)
		(bail_val 0)
		(cr (- yy 0.5))
		(ci xx)
		(zi 0.0)
		(zr 0.0)
		(i 0)
	)
	(while (and (< i MAX_ITERATIONS) (< bail_val BAILOUT))
		(setq i (+ 1 i))
		(setq temp (* zr zi))
		(setq zr2 (* zr zr))
		(setq zi2 (* zi zi))
		(setq zr (+ (- zr2 zi2) cr))
		(setq zi (+ temp temp ci))
		
		(setq bail_val (+ zi2 zr2)))
	i)
)

(defun mandelbrot()
(setq yy -39)
(while (< yy 39)
  (setq yy (+ 1 yy))

  (setq xx -39)
  (while (< xx 39)
    (setq xx (+ 1 xx))
    
    (if (= (iterate (/ xx 40.0) (/ yy 40.0)) 1000)
		(princ  "*")
		(princ  " ")
   )
)
(princ  "\n")
))
(setq the-time (cadr (current-time)))
(mandelbrot)
(princ (format "Elapsed %d" (- (cadr (current-time)) the-time)))

Applescript

(* Applescript Version by Erik Wrenholt
I couldn't figure out how to write to stdout
so it buffers the output until the end. *)

on unixTime()
	(do shell script "date +%s") as integer
end unixTime

on iterate(x, y)
	set BAILOUT to 16
	set MAX_ITERATIONS to 1000
	
	set cr to y - 0.5
	set ci to x
	set zi to 0.0
	set zr to 0.0
	set i to 0
	
	repeat while i < MAX_ITERATIONS
		set i to i + 1
		set temp to zr * zi
		set zr2 to zr * zr
		set zi2 to zi * zi
		set zr to zr2 - zi2 + cr
		set zi to temp + temp + ci
		if zi2 + zr2 > BAILOUT then
			return i
		end if
	end repeat
	return 0
end iterate

set t to unixTime()

set mandelbrotString to ""
set nl to (ASCII character 10)
repeat with y from -39 to 38 by 1
	set mandelbrotString to mandelbrotString & nl
	repeat with x from -39 to 38 by 1
		if iterate(x / 40.0, y / 40.0) = 0 then
			set mandelbrotString to mandelbrotString & "*"
		else
			set mandelbrotString to mandelbrotString & " "
		end if
	end repeat
end repeat

set elapsed to unixTime() - t
mandelbrotString & nl & "Time Elapsed " & elapsed

Io 20070410

#!/usr/local/bin/IoServer
# by Erik Wrenholt

iterator := Object clone do (

bailout := 16
max_iterations := 1000

mandelbrot := method (x,y,
	cr := y - 0.5
	ci := x
	zi := 0.0
	zr := 0.0
	i := 0
	
	while (1,
		i = 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)
	)
)

print_set := method (
	writeln("Rendering...")	
	for(y, -39, 38,
		write("\n")
		for(x, -39, 38,
			i := mandelbrot(x/40.0,y/40.0)
			if (i == 0, write("*"),write(" "))
		)
	)
)
)

writeln
writeln ("Io Elapsed " .. Date secondsToRun(iterator print_set))

SBCL 1.0.2

; sbcl lisp version by mandeep singh

(declaim (optimize (speed 3)))

(defconstant +BAILOUT+ 16)
(defconstant +MAX-ITERATIONS+ 1000)

(defun mandelbrot (x y)
  (declare (type single-float x y))
  (let ((cr (- y 0.5))
        (ci x)
        (zi 0.0)
        (zr 0.0))
    (declare (type single-float cr ci zi zr))
    (do ((i 0 (incf i)))
        (nil)
      (let* ((temp (the single-float (* zr zi)))
             (zr2 (the single-float (* zr zr)))
             (zi2 (the single-float (* zi zi))))
        (declare (type single-float temp zr2 zi2)
                 (type fixnum i))
        (setq zr (the single-float (+ (- zr2 zi2) cr)))
        (setq zi (the single-float (+ temp temp ci)))
        (if (> (the single-float (+ zi2 zr2)) +BAILOUT+)
            (return-from mandelbrot i))
        (if (> i +MAX-ITERATIONS+)
            (return-from mandelbrot 0))))))
 
(defun main ()
   (let ((tstart) 
	(tfinish))
     (setq tstart (get-internal-real-time))
     (do ((y -39 (incf y)))
	 ((= (the fixnum y) 39))
       (format t "~%")
       (do ((x -39 (incf x)))
	   ((= (the fixnum x) 39))
	 (let ((i (mandelbrot (the single-float (/ x 40.0))
			      (the single-float (/ y 40.0)))))
	   (declare (type fixnum i x y))
        (if (zerop i)
            (format t "*")
            (format t " ")))))
     (format t "~%")
     (setq tfinish (get-internal-real-time))
     (format t "SBCL Elapsed ~,2F~%" (coerce (/ (- tfinish tstart) internal-time-units-per-second) 'float))))

(progn 
 (main)
 (quit))		    

Tags: ruby, python, java, php, lua, perl, benchmark, mandelbrot, fractal