Web墨卡托坐标与WGS84坐标互转

//经纬度转墨卡托
-(CGPoint
)lonLat2Mercator:(CGPoint ) lonLat
{
    CGPoint  mercator;
    double
x = lonLat.x *20037508.34/180;
    double y =
log(tan((90+lonLat.y)*M_PI/360))/(M_PI/180);
    y = y *20037508.34/180;
 
  mercator.x = x;
    mercator.y = y;
    return mercator
;
}
//墨卡托转经纬度
-(CGPoint )Mercator2lonLat:(CGPoint ) mercator
{
 
  CGPoint lonLat;
    double x = mercator.x/20037508.34*180;
    double y
= mercator.y/20037508.34*180;
    y=
180/M_PI*(2*atan(exp(y*M_PI/180))-M_PI/2);
    lonLat.x = x;
    lonLat.y
= y;
    return lonLat;
}