Galton-Brett

<?php
function normalverteilung( $max ){
    /*
     * @ see: http://de.wikipedia.org/wiki/Galtonbrett
     */

    $i = 0;
    $random = 0;
    $iteration = $max-1;

    for( $i=0; $i < $iteration; $i++ ){
        $random += mt_rand( 0, 1 );
    }

    return $random;
}

$e = 0;
$iterations = 4711;
$variance = 5;
$result = array_fill( 0, $variance, 0 );

for( $e=0; $iterations > $e; $e++ ){
    $result[ normalverteilung( $variance ) ]++;
}


/*
 * Display results
 */
ksort( $result );

$sum = array_sum( $result );
$percent = $sum / 100;

foreach( $result as $k=>$v ){
    $p = round( ( $v/$percent ), 2);
    $display_array[$k] = $p;
}

echo '<DOCTYPE html><html><head><title>Normalverteilung</title></head><body style="background-color:#666; color:#eee">';
echo '<h2>Normalverteilung</h2>';
printf( "Anzahl Zahlen: %d - Anzahl Durchläufe: %d<hr />", count( $result ), $sum );

$c = 0;
$d = 'f';
foreach( $display_array as $raw ){
    echo '<div><p style="float:left">'.sprintf( "%02d", ($c+1) ).'&nbsp;</p><div style="float:left;background-color:#'.dechex($c).dechex($c).$d.'; width:'.$raw.'em; border:1px solid black; height:2em"><p style="position:relative; bottom:0.2em; left:0.5em">'.$raw.'%</p></div></div><br style="clear:left" />';
    $c++;
        if($c>16)
            $d= 'ff';

}

echo '</body></html>';