<?php
global $timer;

function start_timer() {
	global $timer;
	$timer['start'] = microtime(true);
}

function stop_timer() {
	global $timer;
	$timer['stop'] = microtime(true);
}

function get_timer() {
	global $timer;
	return ($timer['stop'] - $timer['start']);
}
function w_rand($weights) {
	$r = mt_rand(1,10000);
	$offset = 0;
	foreach ($weights as $k => $w) {
		$offset += $w*10000;
		if ($r <= $offset) {
			return $k;
		}
	}
}
$weights = array("one" => 0.09, "two" => 0.11, "pie" => 0.05, "fish" => 0.15, "dog" => 0.30, "oink" => 0.25, "foo" => 0.05);
$r = array();
$size = 2000000;
start_timer();
while ($i++ < $size) {
	$r[w_rand($weights)]++;
}
stop_timer();
echo number_format(get_timer()/$size * 1000,6) . " ms avg. runtime\n\n";

$s = array_sum($r);

echo "key\tpct\t% err\n";
echo "---\t---\t-----\n";
foreach ($weights as $k => $w) {
	$v = $r[$k];
	$t = $v/$s * 100;
	$d = number_format(abs($t - $w*100)/($w),2);
	$t = number_format($t,2);
	echo "{$k}\t$t\t$d%\n";
}
?>