百度地图坐标转换

/**

*  地图位置计算工具(将GPS坐标转换成百度地图坐标)

*    参考文档：http://bbs.lbsyun.baidu.com/forum.php?mod=viewthread&tid=10923&qq-pf-to=pcqq.group

*

*    使用示例：批量转换坐标位置

*

*    var transferedData = GpsToBaiduPoints(prePoints);

*    $.each(transferedData,function(index,point){

*      console.log(point);

*    });

*

*-------------------以下是提供的一个简单的访问接口-------------------------

*    参数: points:new BMap.Point(lng,lat)的集合

*    返回值:resultPoints:转换后 BMap.point点集

*    function GpsToBaiduPoints(points){

*        var resultPoints = [];

*        $.each(points,function(index,point){

*            //世界大地坐标转为百度坐标

*            var _t = wgs2bd(point.lat,point.lng);

*            var _BPoint = new BMap.Point(_t[1], _t[0]);

*            resultPoints.push(_BPoint);

*        });

*        return resultPoints;

*    }

*/

//默认提供一个接口直接调用

function GpsToBaiduPoints(points){

var resultPoints = [];

$.each(points,function(index,point){

var _t = wgs2bd(point.lat,point.lng);

var _BPoint = new BMap.Point(_t[1], _t[0]);

resultPoints.push(_BPoint);

});

return resultPoints;

}

//////////////////////////////////////////

//////////////转换核心代码////////////////

//////////////////////////////////////////

var pi = 3.14159265358979324;

var a = 6378245.0;

var ee = 0.00669342162296594323;

var x_pi = 3.14159265358979324*3000.0/180.0;

//世界大地坐标转为百度坐标

function wgs2bd(lat,lon) {

var wgs2gcjR = wgs2gcj(lat, lon);

var gcj2bdR = gcj2bd(wgs2gcjR[0], wgs2gcjR[1]);

return gcj2bdR;

}

function gcj2bd(lat,lon) {

var x = lon, y = 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);

var bd_lon = z * Math.cos(theta) + 0.0065;

var bd_lat = z * Math.sin(theta) + 0.006;

var result = [];

result.push(bd_lat);

result.push(bd_lon);

return result;

}

function bd2gcj(lat,lon) {

var x = lon - 0.0065, y = lat - 0.006;

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);

var gg_lon = z * Math.cos(theta);

var gg_lat = z * Math.sin(theta);

var result = [];

result.push(gg_lat);

result.push(gg_lon);

return result;

}

function wgs2gcj(lat,lon) {

var dLat = transformLat(lon - 105.0, lat - 35.0);

var dLon = transformLon(lon - 105.0, lat - 35.0);

var radLat = lat / 180.0 * pi;

var magic = Math.sin(radLat);

magic = 1 - ee * magic * magic;

var sqrtMagic = Math.sqrt(magic);

dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);

dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi);

var mgLat = lat + dLat;

var mgLon = lon + dLon;

var result = [];

result.push(mgLat);

result.push(mgLon);

return result;

}

function transformLat(lat,lon) {

var ret = -100.0 + 2.0 * lat + 3.0 * lon + 0.2 * lon * lon + 0.1 * lat * lon + 0.2 * Math.sqrt(Math.abs(lat));

ret += (20.0 * Math.sin(6.0 * lat * pi) + 20.0 * Math.sin(2.0 * lat * pi)) * 2.0 / 3.0;

ret += (20.0 * Math.sin(lon * pi) + 40.0 * Math.sin(lon / 3.0 * pi)) * 2.0 / 3.0;

ret += (160.0 * Math.sin(lon / 12.0 * pi) + 320 * Math.sin(lon * pi  / 30.0)) * 2.0 / 3.0;

return ret;

}

function transformLon(lat,lon) {

var ret = 300.0 + lat + 2.0 * lon + 0.1 * lat * lat + 0.1 * lat * lon + 0.1 * Math.sqrt(Math.abs(lat));

ret += (20.0 * Math.sin(6.0 * lat * pi) + 20.0 * Math.sin(2.0 * lat * pi)) * 2.0 / 3.0;

ret += (20.0 * Math.sin(lat * pi) + 40.0 * Math.sin(lat / 3.0 * pi)) * 2.0 / 3.0;

ret += (150.0 * Math.sin(lat / 12.0 * pi) + 300.0 * Math.sin(lat / 30.0 * pi)) * 2.0 / 3.0;

return ret;

}