Azimuth/Bearing calculation in objective-c

I have been trying this formula to obtain the azimut/bearing of two points of the map.

I mean, to obtain the real north di开发者_StackOverflow中文版rection of the vector done with the two coordinates.

θ =atan2(sin(Δlong).cos(lat2),cos(lat1).sin(lat2)−sin(lat1).cos(lat2).cos(Δlong))

azimut=θ*180/M_PI;

azimuth=(azimuth+360)MOD 360;

I have obtain this formula from this webpage(http://www.yourhomenow.com/house/haversine.html), but i never get the same result.

Is there any other way to obtain the azimut of two points?

Thanks!

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You also need to have Δlong, lat1 and lat2 in radians. Therefore you should multiply all of them by M_PI/180 before starting the calculation.