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[swift] IOS地圖運用 (5) 計算點與點之間的距離

Posted on Edited on Disqus:

網路上有找到Google的計算公式,把它翻譯成Swift的語法後如下,回傳單位為**公里 **

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public static func GetDistance_Google(pointA:CLLocationCoordinate2D , pointB:CLLocationCoordinate2D) -> Double
{
   let EARTH_RADIUS:Double = 6378.137;

   let radlng1:Double = pointA.longitude * M_PI / 180.0;
   let radlng2:Double = pointB.longitude * M_PI / 180.0;

   let a:Double = radlng1 - radlng2;
   let b:Double = (pointA.latitude - pointB.latitude) * M_PI / 180;
   var s:Double = 2 * asin(sqrt(pow(sin(a/2), 2) + cos(radlng1) * cos(radlng2) * pow(sin(b/2), 2)));

   s = s * EARTH_RADIUS;
   s = (round(s * 10000) / 10000);
   return s;
}