如何计算Android应用程序中两点之间的距离

发布于 2024-11-02 18:45:59 字数 384 浏览 1 评论 0原文

在我的应用程序中，我试图计算一个人从一个地方到另一个地方的旅行距离。为此，我使用半正矢公式，

R = earth’s radius (mean radius = 6,371km)
Δlat = lat2− lat1
Δlong = long2− long1
a = sin²(Δlat/2) + cos(lat1).cos(lat2).sin²(Δlong/2)
c = 2.atan2(√a, √(1−a))
d = R.c

获取起始地点和到达地点的纬度和经度，我正在计算以公里为单位的距离。但其他人表示，这种距离计算仅在乘坐飞机出行时有效，如果用户乘坐公路出行，则距离计算会有所不同。

如果是这样，我在道路上行驶时如何获得正确的距离。

请帮助我朋友

原文

in my app i am trying to calculate the distance a person traveling from one place to the other. For that i am using the Haversine formula,

R = earth’s radius (mean radius = 6,371km)
Δlat = lat2− lat1
Δlong = long2− long1
a = sin²(Δlat/2) + cos(lat1).cos(lat2).sin²(Δlong/2)
c = 2.atan2(√a, √(1−a))
d = R.c

getting the latitude and longitude of starting place and reaching place i am calculating the distance in kms. But others say that this distance calculation works only if travelled by airways and get varies if user travels by roadways.

If it is so how can i get a correct distance while traveling through road ways.

please help me friends

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孤单情人 2024-11-09 18:45:59

此方法在标准 API 中（Location.distanceBetween 方法））
http://developer.android.com/reference/android/location/Location.html

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卷耳 2024-11-09 18:45:59

使用以下公式计算两个经纬度之间的距离：

private double calculateDistance(double lat1, double lon1, double lat2, double lon2, String unit) 
{
      double theta = lon1 - lon2;
      double dist = Math.sin(deg2rad(lat1)) * Math.sin(deg2rad(lat2)) + Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) * Math.cos(deg2rad(theta));
      dist = Math.acos(dist);
      dist = rad2deg(dist);
      dist = dist * 60 * 1.1515;
      if (unit == "K") {
        dist = dist * 1.609344;
      } else if (unit == "M") {
        dist = dist * 0.8684;
        }
      return (dist);
}

    /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
    /*::  This function converts decimal degrees to radians             :*/
    /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
    private double deg2rad(double deg) 
    {
      return (deg * Math.PI / 180.0);
    }

    /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
    /*::  This function converts radians to decimal degrees             :*/
    /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
    private double rad2deg(double rad)
    {
      return (rad * 180.0 / Math.PI);
    }

将纬度、经度与所需距离的函数和单位（“K”表示公里，“M”表示英里）传递。
希望这会对您有所帮助。

Use the following formula to find the distance between two lat-longs:

private double calculateDistance(double lat1, double lon1, double lat2, double lon2, String unit) 
{
      double theta = lon1 - lon2;
      double dist = Math.sin(deg2rad(lat1)) * Math.sin(deg2rad(lat2)) + Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) * Math.cos(deg2rad(theta));
      dist = Math.acos(dist);
      dist = rad2deg(dist);
      dist = dist * 60 * 1.1515;
      if (unit == "K") {
        dist = dist * 1.609344;
      } else if (unit == "M") {
        dist = dist * 0.8684;
        }
      return (dist);
}

    /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
    /*::  This function converts decimal degrees to radians             :*/
    /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
    private double deg2rad(double deg) 
    {
      return (deg * Math.PI / 180.0);
    }

    /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
    /*::  This function converts radians to decimal degrees             :*/
    /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
    private double rad2deg(double rad)
    {
      return (rad * 180.0 / Math.PI);
    }

Pass lat,longs with the function and unit in which you want distance ("K" for kilometer and "M" for Miles).
Hope this will help you.

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