class func bd_encrypt(gg_lat:Double,gg_lon: Double) -> (bd_lat:Double,bd_lon: Double) {

var x = gg_lon;

var y = gg_lat;

var z =sqrt(x * x + y * y) + 0.00002 * sin(y * x_pi);

var theta =atan2(y,x) + 0.000003 * cos(x * x_pi);

var bdlon = z *cos(theta) + 0.0065;

var bdlat = z *sin(theta) + 0.006;

return (bdlat,bdlon)

}

classfunc bd_decrypt(bd_lat: Double,bd_lon:Double) -> (gg_lat: Double,gg_lon:Double) {

var x = bd_lon - 0.0065;

var y = bd_lat - 0.006;

var z =sqrt(x * x + y * y) - 0.00002 * sin(y * x_pi);

var theta =atan2(y,x) - 0.000003 * cos(x * x_pi);

var gglon = z *cos(theta);

var gglat = z *sin(theta);

return (gglat,gglon)

}