Write a PHP function to round a float away from zero to a specified number of decimal places

<?php
function roundout ($value, $places=0) {
if ($places < 0) { $places = 0; }
$x= pow(10, $places);
return ($value >= 0 ? ceil($value * $x):floor($value * $x)) / $x;
}
echo roundout (78.78001, 2)."\n";
echo roundout (8.131001, 2)."\n";
echo roundout (0.586001, 4)."\n";
echo roundout (-.125481, 3)."\n";
echo roundout (-.125481);
?>