JS腾讯、谷歌地图坐标转百度地图坐标

function change(lat,lng){    var x_pi = 3.14159265358979324 * 3000.0 / 180.0;    var x = parseFloat(lng);    var y = parseFloat(lat);    var z = Math.sqrt(x * x + y * y) + 0.00002 * Math.sin(y * x_pi);    var theta = Math.atan2(y,x) + 0.000003 * Math.cos(x * x_pi);    lng = z * Math.cos(theta) + 0.0065;    lat = z * Math.sin(theta) + 0.006;}