php获取经纬度计算距离

/** 
 *  @desc 根据两点间的经纬度计算距离 
 *  @param float $lat 纬度值 
 *  @param float $lng 经度值 
 */ 
function getDistance($lat1, $lng1, $lat2, $lng2) { 
     $earthRadius = 6367000; 
     $lat1 = ($lat1 * pi()) / 180; 
     $lng1 = ($lng1 * pi()) / 180; 
     $lat2 = ($lat2 * pi()) / 180; 
     $lng2 = ($lng2 * pi()) / 180; 
     $calcLongitude = $lng2 - $lng1; 
     $calcLatitude = $lat2 - $lat1; 
     $stepOne = pow(sin($calcLatitude / 2), 2) + cos($lat1) * cos($lat2) * pow(sin($calcLongitude / 2), 2);  $stepTwo = 2 * asin(min(1, sqrt($stepOne))); 
     $calculatedDistance = $earthRadius * $stepTwo; 
     return round($calculatedDistance); 
}