两经纬度间距离

/**
 * @param 	 两经纬度间距离  
 * @param    [float]	$lng1 [经度]
 * @param    [float]	$lat1 [纬度]
 * @param    [float]	$lng2 [经度]
 * @param    [float]	$lat2 [纬度]
 * @return   [float]	[距离,单位米]
 */
/*
function getDistance($lng1, $lat1, $lng2, $lat2) {
    // 将角度转为弧度
    $radLat1 = deg2rad($lat1); //deg2rad()函数将角度转换为弧度
    $radLat2 = deg2rad($lat2);
    $radLng1 = deg2rad($lng1);
    $radLng2 = deg2rad($lng2);
    $a = $radLat1 - $radLat2;
    $b = $radLng1 - $radLng2;
    $s = 2 * asin(sqrt(pow(sin($a / 2), 2) + cos($radLat1) * cos($radLat2) * pow(sin($b / 2), 2))) * 6378137;
    $s = round($s * 10000) / 10000;
    return $s;//正确答案：330518.674
} 
function getDistanceAction($lng1, $lat1, $lng2, $lat2){
    $radius = 6378137;   //地球半径
    $rad = pi() / 180.0;
    $radLat1 = $lat1 * $rad;
    $radLat2 = $lat2 * $rad;
    $a = $radLat1 - $radLat2;    // 两点纬度差
    $b = ($lng1 - $lng2) * $rad;  // 两点经度差
    $s = 2 * asin(sqrt(pow(sin($a / 2), 2) + cos($radLat1) * cos($radLat2) * pow(sin($b / 2), 2)));
    $s = $s * $radius;
    $s = round($s * 10000) / 10000;
    return $s;   //正确答案：330518.6740
}
echo getdistance('117.27', '31.86', '120.19', '30.26');echo '<br>';
echo getdistanceAction('117.27', '31.86', '120.19', '30.26');