public function getDistance($lat1, $lng1, $lat2, $lng2)
    {
        $p = 3.1415926535898;
        $r = 6378.137;

        $radLat1 = $lat1 * ($p / 180);
        $radLat2 = $lat2 * ($p / 180);
        $a = $radLat1 - $radLat2;
        $b = ($lng1 * ($p / 180)) - ($lng2 * ($p / 180));
        $s = 2 * asin(sqrt(pow(sin($a / 2), 2) + cos($radLat1) * cos($radLat2) * pow(sin($b / 2), 2)));
        $s = $s * $r;
        $s = round($s * 10000) / 10000;
        return $s;
    }