在實際開發(fā)過程中，由于各種地圖坐標之間的偏差，混用導(dǎo)致結(jié)果不正確，但如果搞清楚他們采用何種坐標，問題就迎刃而解了；
地球坐標(WGS84)
國際標準
例如：CLLocationManager
火星坐標 (GCJ-02)
中國標準
例如：iOS MKMapView、高德地圖、國內(nèi)google 、搜搜、阿里云
百度坐標 (BD-09)
百度標準
例如：百度 SDK，地圖
以下給出相應(yīng)的轉(zhuǎn)換方法：
// a = 6378245.0, 1/f = 298.3
// b = a * (1 - f)
// ee = (a^2 - b^2) / a^2;
let a:Double = 6378245.0
let ee:Double = 0.00669342162296594323
letx_pi:Double=M_PI*3000.0/180.0
importCoreLocation
public extension CLLocation {
? ? /// 從地圖坐標轉(zhuǎn)化到火星坐標
? ? ///
? ? /// - Returns: CLLocation
? ? func locationMarsFromEarth() -> CLLocation {
? ? ? ? let (n_lat,n_lng) = CLLocation.transform_earth_from_mars(lat: self.coordinate.latitude, lng: self.coordinate.longitude)
? ? ? ? let coord_2d = CLLocationCoordinate2D(latitude: n_lat + self.coordinate.latitude, longitude: n_lng + self.coordinate.longitude)
? ? ? ? return CLLocation(coordinate: coord_2d, altitude: self.altitude, horizontalAccuracy: self.horizontalAccuracy, verticalAccuracy: self.horizontalAccuracy, course: self.course, speed: self.speed, timestamp: self.timestamp)
? ? }
? ? /// 從火星坐標到地圖坐標
? ? ///
? ? /// - Returns: CLLocation
? ? func locationEarthFromMars() -> CLLocation {
? ? ? ? let (n_lat,n_lng) = CLLocation.transform_earth_from_mars(lat: self.coordinate.latitude, lng: self.coordinate.longitude)
? ? ? ? let coord_2d = CLLocationCoordinate2D(latitude: self.coordinate.latitude - n_lat, longitude: self.coordinate.longitude - n_lng)
? ? ? ? return CLLocation(coordinate: coord_2d, altitude: self.altitude, horizontalAccuracy: self.horizontalAccuracy, verticalAccuracy: self.horizontalAccuracy, course: self.course, speed: self.speed, timestamp: self.timestamp)
? ? }
? ? /// 從火星坐標轉(zhuǎn)化到百度坐標
? ? ///
? ? /// - Returns: CLLocation
? ? func locationBaiduFromMars() -> CLLocation {
? ? ? ? let (n_lat,n_lng) = CLLocation.transform_mars_from_baidu(lat: self.coordinate.latitude, lng: self.coordinate.longitude)
? ? ? ? letcoord_2d =CLLocationCoordinate2D(latitude: n_lat,longitude: n_lng)
? ? ? ? return CLLocation(coordinate: coord_2d, altitude: self.altitude, horizontalAccuracy: self.horizontalAccuracy, verticalAccuracy: self.horizontalAccuracy, course: self.course, speed: self.speed, timestamp: self.timestamp)
? ? }
? ? /// 從百度坐標到火星坐標
? ? ///
? ? /// - Returns: CLLocation
? ? func locationMarsFromBaidu() -> CLLocation {
? ? ? ? let (n_lat,n_lng) = CLLocation.transform_baidu_from_mars(lat: self.coordinate.latitude, lng: self.coordinate.longitude)
? ? ? ? letcoord_2d =CLLocationCoordinate2D(latitude: n_lat,longitude: n_lng)
? ? ? ? return CLLocation(coordinate: coord_2d, altitude: self.altitude, horizontalAccuracy: self.horizontalAccuracy, verticalAccuracy: self.horizontalAccuracy, course: self.course, speed: self.speed, timestamp: self.timestamp)
? ? }
? ? /// 從百度坐標到地圖坐標
? ? ///
? ? /// - Returns: CLLocation
? ? func locationEarthFromBaidu() -> CLLocation {
? ? ? ? let mars = self.locationMarsFromBaidu()
? ? ? ? let (n_lat,n_lng) = CLLocation.transform_earth_from_mars(lat: mars.coordinate.latitude, lng: mars.coordinate.longitude)
? ? ? ? let coord_2d = CLLocationCoordinate2D(latitude: self.coordinate.latitude - n_lat, longitude: self.coordinate.longitude - n_lng)
? ? ? ? return CLLocation(coordinate: coord_2d, altitude: self.altitude, horizontalAccuracy: self.horizontalAccuracy, verticalAccuracy: self.horizontalAccuracy, course: self.course, speed: self.speed, timestamp: self.timestamp)
? ? }
? ? private class func transform_earth_from_mars(lat: Double, lng: Double) -> (Double, Double) {
? ? ? ? if CLLocation.transform_sino_out_china(lat: lat, lng: lng) {
? ? ? ? ? ? return(lat, lng)
? ? ? ? }
? ? ? ? vardLat =CLLocation.transform_earth_from_mars_lat(lng -105.0, lat -35.0)
? ? ? ? vardLng =CLLocation.transform_earth_from_mars_lng(lng -105.0, lat -35.0)
? ? ? ? letradLat = lat /180.0*M_PI
? ? ? ? varmagic =sin(radLat)
? ? ? ? magic =1-ee* magic * magic
? ? ? ? letsqrtMagic:Double=sqrt(magic)
? ? ? ? dLat = (dLat *180.0) / ((a* (1-ee)) / (magic * sqrtMagic) *M_PI)
? ? ? ? dLng = (dLng *180.0) / (a/ sqrtMagic *cos(radLat) *M_PI)
? ? ? ? return(dLat,dLng)
? ? }
? ? private class func transform_earth_from_mars_lat(_ x: Double,_ y: Double) -> Double {
? ? ? ? varret:Double= -100.0+2.0* x +3.0* y +0.2* y * y +0.1* x * y +0.2*sqrt(fabs(x))
? ? ? ? ret += (20.0*sin(6.0* x *M_PI) +20.0*sin(2.0* x *M_PI)) *2.0/3.0
? ? ? ? ret += (20.0*sin(y *M_PI) +40.0*sin(y /3.0*M_PI)) *2.0/3.0
? ? ? ? ret += (160.0*sin(y /12.0*M_PI) +320*sin(y *M_PI/30.0)) *2.0/3.0
? ? ? ? returnret
? ? }
? ? private class func transform_earth_from_mars_lng(_ x: Double,_ y: Double) -> Double {
? ? ? ? varret:Double=300.0+ x +2.0* y +0.1* x * x +0.1* x * y +0.1*sqrt(fabs(x))
? ? ? ? ret += (20.0*sin(6.0* x *M_PI) +20.0*sin(2.0* x *M_PI)) *2.0/3.0
? ? ? ? ret += (20.0*sin(x *M_PI) +40.0*sin(x /3.0*M_PI)) *2.0/3.0
? ? ? ? ret += (150.0*sin(x /12.0*M_PI) +300.0*sin(x /30.0*M_PI)) *2.0/3.0
? ? ? ? returnret
? ? }
? ? private class func transform_mars_from_baidu(lat: Double, lng: Double) -> (Double,Double) {
? ? ? ? letx = lng , y = lat
? ? ? ? letz =sqrt(x * x + y * y) +0.00002*sin(y *x_pi)
? ? ? ? lettheta =atan2(y, x) +0.000003*cos(x *x_pi)
? ? ? ? return(z *sin(theta) +0.006, z *cos(theta) +0.0065)
? ? }
? ? private class func transform_baidu_from_mars(lat: Double, lng: Double) -> (Double,Double) {
? ? ? ? letx = lng -0.0065, y = lat -0.006
? ? ? ? letz =? sqrt(x * x + y * y) -0.00002*sin(y *x_pi)
? ? ? ? lettheta =atan2(y, x) -0.000003*cos(x *x_pi)
? ? ? ? return(z *sin(theta), z *cos(theta))
? ? }
? ? private class func transform_sino_out_china(lat: Double, lng: Double) -> Bool {
? ? ? ? if(lng <72.004|| lng >137.8347) {
? ? ? ? ? ? returntrue
? ? ? ? }
? ? ? ? if(lat <0.8293|| lat >55.8271) {
? ? ? ? ? ? returntrue
? ? ? ? }
? ? ? ? return false
? ? }
}
