Calculate Distance Between Two Points using PHP

<?php
function my_getDistanceBetweenPoints($latitude1, $longitude1, $latitude2, $longitude2) {
$theta = $longitude1 - $longitude2;
$miles = (sin(deg2rad($latitude1)) * sin(deg2rad($latitude2))) + (cos(deg2rad($latitude1)) * cos(deg2rad($latitude2)) * cos(deg2rad($theta)));
$miles = acos($miles);
$miles = rad2deg($miles);
$miles = $miles * 60 * 1.1515;
$feet = $miles * 5280;
$yards = $feet / 3;
$kilometers = $miles * 1.609344;
$meters = $kilometers * 1000;
return compact('miles','feet','yards','kilometers','meters');
}
$point_A = array('lat' => 40.770623, 'long' => -73.964367);
$point_B = array('lat' => 40.758224, 'long' => -73.917404);
$show_distance = my_getDistanceBetweenPoints($point_A ['lat'], $point_A ['long'], $point_B ['lat'], $point_B ['long']);
foreach ($show_distance as $unit => $value) {
echo $unit.': '.number_format($value,4).'<br />';
}
?>