Question

在我的Android应用程序中，我计算用户当前位置与用户点击地图的点之间的距离。我用这个函数来计算：

     public double CalculationByDistance(LatLng StartP, LatLng EndP) {
     int Radius=6371;//radius of earth in Km         
     double lat1 = StartP.latitude;
     double lat2 = EndP.latitude;
     double lon1 = StartP.longitude;
     double lon2 = EndP.longitude;
     double dLat = Math.toRadians(lat2-lat1);
     double dLon = Math.toRadians(lon2-lon1);
     double a = Math.sin(dLat/2) * Math.sin(dLat/2) +
    Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2)) *
    Math.sin(dLon/2) * Math.sin(dLon/2);
    double c = 2 * Math.asin(Math.sqrt(a));
    double valueResult= Radius*c;
    double km=valueResult/1;
    DecimalFormat newFormat = new DecimalFormat("####");
    int kmInDec =  Integer.valueOf(newFormat.format(km));
    double meter=valueResult%1000;
    int  meterInDec= Integer.valueOf(newFormat.format(meter));
    Log.i("Radius Value",""+valueResult+"   KM  "+kmInDec+" Meter   "+meterInDec);

    return Radius * c;
    }

但是我的结果距离很长，例如。我到达距离大约20米的两个地方之间的距离为10947公里。任何人都可以帮助我吗？

Answer 1

Android提供了计算两个纬度/经度点之间距离的方法。

android.location.Location.distanceBetween(double startLatitude,
    double startLongitude, double endLatitude, double endLongitude, float[] results)

Answer 2

使用此方法：

        private double distance(double lat1, double lon1, double lat2,
            double lon2) {
        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;
        return (dist);
    }

或者只需查看此conversation

即可

Answer 3

搜索有关Haversine方程式。这是一个在Meter中返回距离的实现：

public static double haversine(double lat1, double lon1, double lat2, double lon2) {
    double dLat = Math.toRadians(lat2 - lat1);
    double dLon = Math.toRadians(lon2 - lon1);
    lat1 = Math.toRadians(lat1);
    lat2 = Math.toRadians(lat2);

    double a = Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.sin(dLon / 2) * Math.sin(dLon / 2) * Math.cos(lat1) * Math.cos(lat2);

    double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));

    return R * c;
}

其中R = 6371000;

Answer 4

以公里计算距离的方法

public static double distanceKM(double lat1, double lon1, double lat2,
            double lon2) {
        int EARTH_RADIUS_KM = 6371;
        double lat1Rad = Math.toRadians(lat1);
        double lat2Rad = Math.toRadians(lat2);
        double deltaLonRad = Math.toRadians(lon2 - lon1);

        double dist_travelled = Math
                .acos(Math.sin(lat1Rad) * Math.sin(lat2Rad) + Math.cos(lat1Rad)
                        * Math.cos(lat2Rad) * Math.cos(deltaLonRad))
                * EARTH_RADIUS_KM;

        dist_travelled = Double.parseDouble(new DecimalFormat("##.######")
                .format(dist_travelled));
        return dist_travelled;

    }

如何使用LatLng在谷歌地图v2中获得两公里之间的距离

4 个答案: