Monte Carlo Pi Estimation

montepi.php

<?php

$iterations = isset($argv[1]) ? (int) $argv[1] : 100000000;
$randmax = mt_getrandmax();
$hits = 0;

for ($i = 0; $i < $iterations; ++$i) {
    $x = mt_rand() / $randmax;
    $y = mt_rand() / $randmax;
    if (sqrt($x * $x + $y * $y) <= 1.0) {
        ++$hits;
    }
}

printf("Pi: %0.6f\n", (4 * ($hits / $iterations)));