functions to use and smooth course from CLLocationManager and get north angle relative to current angle

courseAngles.swift

   var courseAvgX: Double = 0
    var courseAvgY: Double = 0
    
    func getVectorAvg(latestReading: Double) -> Double {
        
        let deg2Rad = 180 / Double.pi
        // convert reading to radians
        var theta = latestReading / deg2Rad
        
        // running average
        courseAvgX = courseAvgX * 0.5 + cos(theta) * 0.5;
        courseAvgY = courseAvgY * 0.5 + sin(theta) * 0.5;
        
        // get the result in degrees
        var avgAngleDeg =  atan2(courseAvgY, courseAvgX) * deg2Rad;
        
        // result is -180 to 180. change this to 0-360.
        if(avgAngleDeg < 0){ avgAngleDeg = avgAngleDeg + 360}
        
        return avgAngleDeg;
    }
    
    
    
    
    
    
    // location
    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        
        guard let location = locations.last else {
            return
        }
        
        let lat = location.coordinate.latitude
        let lon = location.coordinate.longitude
        let alt = location.altitude
        let course = location.course
        
        currentLat = lat;
        currentLon = lon;
        
        print("location.course: \(course)" )
        
        
        let avgCourse = getVectorAvg(latestReading: course)
        
        print("avgCourse: \(avgCourse)")
        
        
        self.navIndicatorView.courseAngle = CGFloat(360.0 - avgCourse + course) * -1.0
        
        
        self.navIndicatorView.northAngle = CGFloat(360.0 - course) * -1.0
        
        // print("northAngle: \(self.navIndicatorView.northAngle)")
        
     
        
        labelLatVal.text = String(format: "%.6f", lat)
        labelLonVal.text = String(format: "%.6f", lon)
        labelAltVal.text = String(format: "%.f", alt * GeoMath.metersToFeet)
        labelCourseVal.text = String(format: "%.1f", course)
        labelHeadingVal.text = String(format: "%.1f", (avgCourse))
        
    }