如何在JavaScript中找到我与已知位置的距离 [英] How to find my distance to a known location in JavaScript

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本文介绍了如何在JavaScript中找到我与已知位置的距离的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

在浏览器中使用JavaScript,如何确定从当前位置到另一个具有经度和纬度的位置的距离? 解决方案

如果您的代码在浏览器中运行,您可以使用HTML5地理定位API:

  window.navigator。 geolocation.getCurrentPosition(function(pos){
console.log(pos);
var lat = pos.coords.latitude;
var lon = pos.coords.longitude;
})

一旦您知道了目标的当前位置和位置,就可以计算他们之间的距离按照这个问题中记录的方式:计算两个纬度经度点之间的距离? (Haversine公式)



因此,完整的脚本变成:



函数距离(lon1,lat1,lon2,lat2){
var R = 6371; //以公里为单位的地球半径
var dLat =(lat2-lat1).toRad(); //以弧度表示的Javascript函数
var dLon =(lon2-lon1).toRad();
var a = Math.sin(dLat / 2)* Math.sin(dLat / 2)+
Math.cos(lat1.toRad())* Math.cos(lat2.toRad()) *
Math.sin(dLon / 2)* Math.sin(dLon / 2);
var c = 2 * Math.atan2(Math.sqrt(a),Math.sqrt(1-a));
var d = R * c; //以公里为单位的距离
返回d;
$ **
$ b / **将数值度数转换为弧度* /
if(typeof(Number.prototype.toRad)===undefined){
Number .prototype.toRad = function(){
return this * Math.PI / 180;



window.navigator.geolocation.getCurrentPosition(function(pos){
console.log(pos);
console.log
距离(pos.coords.longitude,pos.coords.latitude,42.37,71.03)
);
});

显然,我现在距马萨诸塞州波士顿市中心6643米(这是硬编码的第二

请参阅以下链接以获取更多信息:


Using JavaScript in the browser, how can I determine the distance from my current location to another location for which I have the latitude and longitude?

解决方案

If your code runs in a browser, you can use the HTML5 geolocation API:

window.navigator.geolocation.getCurrentPosition(function(pos) { 
  console.log(pos); 
  var lat = pos.coords.latitude;
  var lon = pos.coords.longitude;
})

Once you know the current position and the position of your "target", you can calculate the distance between them in the way documented in this question: Calculate distance between two latitude-longitude points? (Haversine formula).

So the complete script becomes:

function distance(lon1, lat1, lon2, lat2) {
  var R = 6371; // Radius of the earth in km
  var dLat = (lat2-lat1).toRad();  // Javascript functions in radians
  var dLon = (lon2-lon1).toRad(); 
  var a = Math.sin(dLat/2) * Math.sin(dLat/2) +
          Math.cos(lat1.toRad()) * Math.cos(lat2.toRad()) * 
          Math.sin(dLon/2) * Math.sin(dLon/2); 
  var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a)); 
  var d = R * c; // Distance in km
  return d;
}

/** Converts numeric degrees to radians */
if (typeof(Number.prototype.toRad) === "undefined") {
  Number.prototype.toRad = function() {
    return this * Math.PI / 180;
  }
}

window.navigator.geolocation.getCurrentPosition(function(pos) {
  console.log(pos); 
  console.log(
    distance(pos.coords.longitude, pos.coords.latitude, 42.37, 71.03)
  ); 
});

Apparently I am 6643 meters from the center of Boston, MA right now (that's the hard-coded second location).

See these links for more information:

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