Rasher's Toolbox - lat_lon

int lat_lon_dist(lat1, lon1, lat2, lon2 [, emperic]) -- Calculate the distance between two coordinates.

Description

Calculates the distance between the two coordinates defined by lat1,lon1 and lat2,lon2. Returns in km unless the optional fifth parameter is set to true, in which case the result will be returned in miles. The function was found on http://sourceforge.net/snippet/detail.php?type=snippet&id=100060 and the fifth parameter added by me.

Example

<?php echo "Distance from New York to Paris is ".lat_lon_dist(48.8667, 2.3333, 40.7000, -74.0000)."km."; ?>

This will output:

Distance from New York to Paris is 5828.092745214km.

Source


<?php
function lat_lon_dist($lat1, $lon1, $lat2, $lon2, $emperic = false) {
    $dist = acos(sin(deg2rad($lat1)) * sin(deg2rad($lat2)) + cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($lon1 - $lon2)));
    $dist = rad2deg($dist);
    $miles = $dist * 69;
    if ($emperic !== false) { return $miles; }
    else { return $miles * 1.609344; }
}
?>