>>>So far, so good:

        public static void Main()
>>>        {
>>>            var result = GetAverage(new int[] {357, 2, 359, 356, 4, 2, 355, 22});  //Result : 2
>>>            result = GetAverage(new int[] { 180, 182, 175, 178, 183, 185, 177, 172 });   //Result: 44 :-{
>>>        }
>>>
>>>        public static double GetAverage(int[] values)
>>>        {
>>>            double c = 0;
>>>            double s = 0;
>>>
>>>            foreach (int i in values)
>>>            {
>>>                double r = DegreeToRadian(i);
>>>                c += Math.Cos(r);
>>>                s += Math.Sin(r);
>>>            }
>>>
>>>            double a = Math.Atan2(s, c);
>>>
>>>            return RadianToDegree(a);
>>>        }
>>>
>>>        public static double DegreeToRadian(double angle)
>>>        {
>>>            return Math.PI * angle / 180.0;
>>>        }
>>>
>>>        public static double RadianToDegree(double angle)
>>>        {
>>>            return angle * (180.0 / Math.PI);
>>>        }

>>> More testing......
>>
>>
>>Took a bit of your code - adding vectors
>>To my surprise Atan2() is clever - and returns the right quadrant
>>
>>

>>		public static int GetAverage(IEnumerable<int> readings)
>>		{
>>			double s = 0.0, c = 0.0;
>>			bool haveData = false;
>>
>>			foreach (int value in readings)
>>			{
>>				double rads = DegreeToRadian(value);
>>				
>>				s += Math.Sin(rads);
>>				c += Math.Cos(rads);
>>				haveData = true;
>>			}
>>			
>>			int result = 0;
>>			if (haveData)
>>			{
>>				double rads;
>>
>>				if (c == 0)
>>				{
>>					rads = s >= 0.00 ? Math.PI / 2.0 : -Math.PI / 2.0;
>>				}
>>				else
>>					rads = Math.Atan2(s, c);
>>
>>				result  = (int)RadianToDegree(rads);
>>
>>			}
>>			return result;
>>		}
>>		public static double DegreeToRadian(double degrees)
>>		{
>>			return Math.PI * Modulo(degrees, 360.00) / 180.0;
>>		}
>>
>>		 public static double RadianToDegree(double rads)
>>		{
>>			return Modulo(rads, Math.PI * 2) * (180.0 / Math.PI);
>>		}
>>		public static double Modulo(double dividend, double divisor)
>>		{
>>			return (dividend % divisor)
>>					+ (Math.Sign(dividend) * Math.Sign(divisor) >= 0 ? 0 : divisor);
>>		}
>>

I ended up with this (JScript):

function getAverageAngle(angleArray) {
>    var c = 0;
>    var s = 0;
>    
>    for (var i = 0; i < angleArray.length; i++) {
>        var r = degreeToRadian(angleArray[i]);
>        c += Math.cos(r);
>        s += Math.sin(r);
>    }
>    var a = Math.atan2(s, c);
>    var result = radianToDegree(a);
>    if (result < 0)
>        result = 360 + result;
>    return result;
>}
>
>function degreeToRadian(angle) {
>    return Math.PI * angle / 180;
>}
>
>function radianToDegree(angle) {
>    return angle * (180 / Math.PI);
>}

Raw and average seem to tally.


Right - and to my surprise Atan2 also works when the cosine is zero