WebMercator和geographic互相转换

//经纬度转Web墨卡托
function lonLat2WebMercator(wx,wy){
    var x = wx *20037508.34/180;
    var y = Math.log(Math.tan((90+wy)*Math.PI/360))/(Math.PI/180);
    y = y * 20037508.34/180;
    return {x:x,y:y};
}
//Web墨卡托转经纬度
function WebMercator2lonLat(cx,cy){
    var x = cx/20037508.34*180;
    var y = cy/20037508.34*180;
    y = 180/Math.PI*(2*(Math.exp(y*Math.PI/180))-Math.PI/2);
    return {x:x,y:y};
}