js两个点经纬度计算两点之间的距离。

百度地图经纬度坐标拾取：

http://api.map.baidu.com/lbsapi/getpoint/index.html

var EARTH_RADIUS = 6378137.0; //单位M var PI = Math.PI; function getRad(d) { return d * PI / 180.0; } /** * caculate the great circle distance * @param {Object} lat1 纬度 * @param {Object} lng1 经度 * @param {Object} lat2 * @param {Object} lng2 */ function getFlatternDistance(lat1,lng1,lat2,lng2){ var f = getRad((lat1 + lat2)/2); var g = getRad((lat1 - lat2)/2); var l = getRad((lng1 - lng2)/2); 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 = EARTH_RADIUS; 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; return d*(1 + fl*(h1*sf*(1-sg) - h2*(1-sf)*sg)); } getFlatternDistance(22.576979, 114.065712, 22.574034, 114.065739);

结果如下：