废话不多说,上代码
function countDist(lat1, lng1, lat2, lng2) {//纬度1,经度1,纬度2,经度2
var f = ((lat1 + lat2) / 2) * Math.PI / 180.0;
var g = ((lat1 - lat2) / 2) * Math.PI / 180.0;
var l = ((lng1 - lng2) / 2) * Math.PI / 180.0;
var sg = Math.sin(g);
var sl = Math.sin(l);
var sf = Math.sin(f);
var s, c, w, r, d, h1, h2;
var a = 6378137.0;//地球的直径
var fl = 1 / 298.257;
sg = sg * sg;
sl = sl * sl;
sf = sf * sf;
s = sg * (1 - sl) + (1 - sf) * sl;
c = (1 - sg) * (1 - sl) + sf * sl;
w = Math.atan(Math.sqrt(s / c));
r = Math.sqrt(s * c) / w;
d = 2 * w * a;
h1 = (3 * r - 1) / 2 / c;
h2 = (3 * r + 1) / 2 / s;
var num = d * (1 + fl * (h1 * sf * (1 - sg) - h2 * (1 - sf) * sg))
return num;//返回单位:米
}
