Here the code modified with the changes suggested by Oren Trutner and from myself:
#define degreesToRadians(x) (M_PI * x / 180.0)
#define radiansToDegrees(x) (x * 180.0 / M_PI)
- (float)getHeadingForDirectionFromCoordinate:(CLLocationCoordinate2D)fromLoc toCoordinate:(CLLocationCoordinate2D)toLoc
{
float fLat = degreesToRadians(fromLoc.latitude);
float fLng = degreesToRadians(fromLoc.longitude);
float tLat = degreesToRadians(toLoc.latitude);
float tLng = degreesToRadians(toLoc.longitude);
float degree = radiansToDegrees(atan2(sin(tLng-fLng)*cos(tLat), cos(fLat)*sin(tLat)-sin(fLat)*cos(tLat)*cos(tLng-fLng)));
if (degree >= 0) {
return degree;
} else {
return 360+degree;
}
}