the website of xero harrison

abstract render tutorial

2008-10-11T02:11:00-04:00

this is a "long image" tutorial i did under my alias 0x000000 for igraphixz.com

another as3 range seeded randomizer

2008-04-10T15:44:00-04:00

just another take on a classic piece of code. the pseudo-random number generator. this one is almost the same, just a slightly diffrent algorithm.

private function randomizer(low:Number, high:Number):Number {
	var num:Number = high-low;
	return (Math.random()*num)+low;
}

then use it...

var x:Number = randomizer(5, 50);

i <3 randomization

the lorenz attractor

2008-02-09T11:52:00-05:00

we were discussing recursive algorithms and chaos theory at work yesterday. when one of the chemistry professors brought up the lorenz attractor. he was trying to draw one on the white board for about 10 minutes until i decided it would be easier to draw in flash, lol!

after a quick conversation w/ andy zupko about the new Line3D object, and my new CanvasView3D component for papervision, i made a sweet lorenz attractor!

the algorithm is super simple:

x1 = x0 + h * a * (y0 - x0);
y1 = y0 + h * (x0 * (b - z0) - y0);
z1 = z0 + h * (x0 * y0 - c * z0);

asp.net random number generator

2007-10-18T17:55:00-04:00

here is my asp.net randomizer class based on the c R250/512 shift-register sequence random number generator, by kirkpatrick and stoll and published (j. computational physics, vol 40, pp. 517-526) with an added a pseudo-random class redefinition and buffer overflow protection.

example usage:

randomizer x = new randomizer();
int num = x.random();

actionscript3 randomizer

2007-07-03T19:36:00-04:00

here a nice little one liner. this function returns a random number between a user supplied range.

function randomizer (low:Number, high:Number):Number {
   return Math.floor(low + (Math.random() * (high-low)));
}

example useage, will return a number between 5 - 50.

var x:Number = randomizer(5, 50);

random page perl script

2003-11-18T16:27:00-05:00

place this code in a file called index.cgi, chmod it to 775, and place it in a directory of html files. this script will pick one of the files in the specified directory at random, and print it to the screen. refresh the page for a new random one.

#!/usr/bin/perl
print "Content-type: text/html\n\n";
 
#print "";
$basep = "/wwwroot/path2/randomdir";
 
srand(time ^ $$);
#print "got random time...\n";
 
@files = `ls $basep/*.html`;
#print "got file list...\n";
#foreach (@files) { print "-----$_\n";}
 
$file = rand(@files);
#print "got random file...$phrase\n";
 
$nupath = "$files[$file]";
#print "got new path...$nupath\n";
 
open(LOG, $nupath) or die "$!\n"; 
while () 
{
  print $_;
}
close (LOG);
#print "";

exit;