以米为单位计算两个位置之间的距离 [英] Calculate distance between two locations in metre

问题描述

我有两个地点，我想用米计算距离。

  private void getDistancBetweenTwoPoints（double lat1，double lon1，double lat2，double lon2）我写了一些代码，但它并不完美。 
 {
位置loc1 =新位置（）; 
 loc1.setLatitude（lat1）; 
 loc1.setLongitude（lon1）; 
 
位置loc2 =新位置（）; 
 loc2.setLatitude（lat2）; 
 loc2.setLongitude（lon2）; 
 
 int R = 6371; // km 
 
 double dLat = deg2rad（lat2-lat1）; 
 double dLon = deg2rad（lon2-lon1）; 
 double a = 
 Math.sin（dLat / 2）* Math.sin（dLat / 2）+ 
 Math.cos（deg2rad（lat1））* Math.cos（deg2rad（lat2 ））* 
 Math.sin（dLon / 2）* Math.sin（dLon / 2）
; 
 double c = 2 * Math.atan2（Math.sqrt（a），Math.sqrt（1-a））; 
 double distanceInMeters = R * c; 
 Log.e（distanceInMeters，distanceInMeters / 10000 +mm）; 
} 
 
 public double deg2rad（double deg）{
 return deg *（Math.PI / 180）; 
} 
  

如何以米为单位计算距离？我的目标是，如果米> 200做一些事情。如何解决我的问题？

解决方案

无需为此重新发明轮子。您可以使用 Location.distanceBetween（）方法。

From 文档：

计算两个地点之间的近似距离（单位：米）
blockquote>

下面是一个简单的例子：

  private float getDistancBetweenTwoPoints （double lat1，double lon1，double lat2，double lon2）{
 
 float [] distance = new float [2]; 
 
 Location.distanceBetween（lat1，lon1，
 lat2，lon2，distance）; 
 
返回距离[0]; 
 
 
 
 $ b $ p 
 $ b如果结果数组不仅包含索引零，包含一个方位（初始和最终）。 
 
 
方位是指定罗盘方向的数字。  
 
 
从 http：// www。 geomidpoint.com/destination/help.html ： 
 
 
 
 
方位角（或方位角）是从
的起始点，并且必须在0到360的范围内。0表示
北，90表示东，180表示南，270表示西。 
 
 
I have two locations and I want to calculate distance in meter. I wrote some code but it's not working perfectly.
private void getDistancBetweenTwoPoints(double lat1,double lon1,double lat2,double lon2)
{
    Location loc1 = new Location("");
    loc1.setLatitude(lat1);
    loc1.setLongitude(lon1);

    Location loc2 = new Location("");
    loc2.setLatitude(lat2);
    loc2.setLongitude(lon2);

    int R = 6371; // km

    double dLat = deg2rad(lat2-lat1);
    double dLon = deg2rad(lon2-lon1);
    double  a =
            Math.sin(dLat/2) * Math.sin(dLat/2) +
                    Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) *
                            Math.sin(dLon/2) * Math.sin(dLon/2)
            ;
    double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
    double distanceInMeters = R * c;
    Log.e("distanceInMeters",distanceInMeters/10000+"mm");
}

public double  deg2rad(double deg) {
    return deg * (Math.PI/180);
}
How can I calculate distance in meter? My goal is, if meter > 200 do something. How can i solve my problem?
解决方案
There is no need to re-invent the wheel for this.


You can just use the Location.distanceBetween() method.

From the documentation:

  
Computes the approximate distance in meters between two locations
Here is a simple example:
private float getDistancBetweenTwoPoints(double lat1,double lon1,double lat2,double lon2) {

    float[] distance = new float[2];

    Location.distanceBetween( lat1, lon1,
            lat2, lon2, distance);

    return distance[0];
}
If the result array has more than just index zero populated, the other indices each contain a bearing (initial and final).

A bearing is a number that specifies a compass direction. 

From http://www.geomidpoint.com/destination/help.html :

  
The bearing (or azimuth) is the compass direction to travel from the
  starting point, and must be within the range 0 to 360. 0 represents
  north, 90 is east, 180 is south and 270 is west.


                        
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