转载：高德地图计算2点之间的距离

//搜索出来的代码，原作者不明，先拿来研究
function LngLat(longitude, latitude) {
this.longitude = longitude;
this.latitude = latitude;
}

function calculateLineDistance(start, end) {
var d1 = 0.01745329251994329;
var d2 = start.longitude;
var d3 = start.latitude;
var d4 = end.longitude;
var d5 = end.latitude;
d2 *= d1;
d3 *= d1;
d4 *= d1;
d5 *= d1;
var d6 = Math.sin(d2);
var d7 = Math.sin(d3);
var d8 = Math.cos(d2);
var d9 = Math.cos(d3);
var d10 = Math.sin(d4);
var d11 = Math.sin(d5);
var d12 = Math.cos(d4);
var d13 = Math.cos(d5);
var arrayOfDouble1 = [];
var arrayOfDouble2 = [];
arrayOfDouble1.push(d9 * d8);
arrayOfDouble1.push(d9 * d6);
arrayOfDouble1.push(d7);
arrayOfDouble2.push(d13 * d12);
arrayOfDouble2.push(d13 * d10);
arrayOfDouble2.push(d11);
var d14 = Math.sqrt((arrayOfDouble1[0] - arrayOfDouble2[0]) * (arrayOfDouble1[0] - arrayOfDouble2[0]) +
(arrayOfDouble1[1] - arrayOfDouble2[1]) * (arrayOfDouble1[1] - arrayOfDouble2[1]) +
(arrayOfDouble1[2] - arrayOfDouble2[2]) * (arrayOfDouble1[2] - arrayOfDouble2[2]));
return(Math.asin(d14 / 2.0) * 12742001.579854401);
}
var start = new LngLat("116.368904", "39.923423");
var end = new LngLat("116.387271", "39.922501");

console.log(start,end);

console.log(calculateLineDistance(start, end));