code: function(originLL, destLL) {
  
  			var keys = geolib.getKeys(originLL);
  			var latitude = keys.latitude;
  			var longitude = keys.longitude;
  
  			// difference of longitude coords
  			var diffLon = geolib.useDecimal(destLL[longitude]).toRad() - geolib.useDecimal(originLL[longitude]).toRad();
  
  			// difference latitude coords phi
  			var diffPhi = Math.log(Math.tan(geolib.useDecimal(destLL[latitude]).toRad() / 2 + Math.PI / 4) / Math.tan(geolib.useDecimal(originLL[latitude]).toRad() / 2 + Math.PI / 4));
  
  			// recalculate diffLon if it is greater than pi
  			if(Math.abs(diffLon) > Math.PI) {
  				if(diffLon > 0) {
  					diffLon = (2 * Math.PI - diffLon) * -1;
  				}
  				else {
  					diffLon = 2 * Math.PI + diffLon;
  				}
  			}
  
  			//return the angle, normalized
  			return (Math.atan2(diffLon, diffPhi).toDeg() + 360) % 360;
  
  		}
docs: Gets rhumb line bearing of two points. Find out about the difference between rhumb line and
  great circle bearing on Wikipedia. It's quite complicated. Rhumb line should be fine in most cases:
  
  http://en.wikipedia.org/wiki/Rhumb_line#General_and_mathematical_description
  
  Function heavily based on Doug Vanderweide's great PHP version (licensed under GPL 3.0)
  http://www.dougv.com/2009/07/13/calculating-the-bearing-and-compass-rose-direction-between-two-latitude-longitude-coordinates-in-php/
  
  @param		object		origin coordinate (e.g. {latitude: 51.5023, longitude: 7.3815})
  @param		object		destination coordinate
  @return		integer		calculated bearing