Calculating Bearing Between Two Cllocation Points in Swift

Calculating bearing between two CLLocation points in Swift

Here is an Objective-C solution

• CLLocation Category for Calculating Bearing w/ Haversine function

which can easily be translated to Swift:

func degreesToRadians(degrees: Double) -> Double { return degrees * .pi / 180.0 }
func radiansToDegrees(radians: Double) -> Double { return radians * 180.0 / .pi }

func getBearingBetweenTwoPoints1(point1 : CLLocation, point2 : CLLocation) -> Double {

    let lat1 = degreesToRadians(degrees: point1.coordinate.latitude)
    let lon1 = degreesToRadians(degrees: point1.coordinate.longitude)

    let lat2 = degreesToRadians(degrees: point2.coordinate.latitude)
    let lon2 = degreesToRadians(degrees: point2.coordinate.longitude)

    let dLon = lon2 - lon1

    let y = sin(dLon) * cos(lat2)
    let x = cos(lat1) * sin(lat2) - sin(lat1) * cos(lat2) * cos(dLon)
    let radiansBearing = atan2(y, x)

    return radiansToDegrees(radians: radiansBearing)
}

The result type is Double because that is how all location coordinates are
stored (CLLocationDegrees is a type alias for Double).

Calculating bearing between two CLLocationCoordinate2Ds

Your math is correct, with the following exceptions:

1. Make sure to convert fLat, fLon, tLat, and tLon to radians before applying any sin() or cos() to them. Divide by 180.0 and multiply by PI.

2. Enter the delta between tLng and fLng as tLng-fLng, and not the other way around. Note that this difference appears twice in the expression.

With those changes, I am getting 1.18660677830947 radians with double precision math and the values in the question.

CLLocation Category for Calculating Bearing w/ Haversine function

Your code seems fine to me. Nothing wrong with the calculous. You don't specify how far off your results are, but you might try tweaking your radian/degrees converters to this:

double DegreesToRadians(double degrees) {return degrees * M_PI / 180.0;};
double RadiansToDegrees(double radians) {return radians * 180.0/M_PI;};

If you are getting negative bearings, add 2*M_PI to the final result in radiansBearing (or 360 if you do it after converting to degrees). atan2 returns the result in the range -M_PI to M_PI (-180 to 180 degrees), so you might want to convert it to compass bearings, using something like the following code

if(radiansBearing < 0.0)
    radiansBearing += 2*M_PI;

Bearing of Current location in iOS SDK

CLLocation has a course property (type CLLocationDirection) which is the bearing. From the docs:

Course values are measured in degrees starting at due north and continuing clockwise around the compass. Thus, north is 0 degrees, east is 90 degrees, south is 180 degrees, and so on. Course values may not be available on all devices. A negative value indicates that the direction is invalid.

How to find out distance between coordinates?

CLLocation has a distanceFromLocation method so given two CLLocations:

CLLocationDistance distanceInMeters = [location1 distanceFromLocation:location2];

or in Swift 4:

//: Playground - noun: a place where people can play

import CoreLocation


let coordinate₀ = CLLocation(latitude: 5.0, longitude: 5.0)
let coordinate₁ = CLLocation(latitude: 5.0, longitude: 3.0)

let distanceInMeters = coordinate₀.distance(from: coordinate₁) // result is in meters

you get here distance in meter so 1 miles = 1609 meter

if(distanceInMeters <= 1609)
 {
 // under 1 mile
 }
 else
{
 // out of 1 mile
 }

Calculate offset between two CLLocationCoordinate2D locations

If I understand, what you're trying to get is the distance between 2 known location in degrees ?

If this is it then try :

class func getDistancesInDegrees(origin:CLLocationCoordinate2D, destination:CLLocationCoordinate2D) -> (degLat: CLLocationDegrees, degLon:CLLocationDegrees) {
    var latidueDegrees:CLLocationDegrees = Double(origin.coordinate.latitude) - Double(destination.coordinate.latitude)
    var longitudeDegrees:CLLocationDegrees = Double(origin.coordinate.longitude) - Double(destination.coordinate.longitude)

    return (degLat: latidueDegrees, degLon:longitudeDegrees)
}

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