Math help - rolling average Wind Direction

[skimask]

Maybe I'm thinking linearly too, but doesn't that just move the problem from North to South?
At a little SE its 179 or less, and move a little SW and it's -179 or more, which averages to 0 or North.
Maybe there's another trick in that hint?
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What I'm thinkin...(without colons this time )
1st reading is 30 degrees, 2nd reading is 330 degrees, average wanted should be 0 degrees, obviously the AVERAGE is 180...no good...but...
if you take the sin and cos of 30, you get .5 and .866...
if you take the sin and cos of 330, you get -.5 and .866...
the average of the .5 and -.5 is 0, sin(0)=0 (average of .5 & -.5)...
but I'm stuck at what to do with the 2 cosine values. Maybe this example is just a 'special case' where the result is right one 'axis' lines of a graph...
More thought needed...I know the answer is right here...just have to put my finger on it...

Or maybe you could treat the first 30 degree reading as actually 390 (360 + 30), then do the averaging, which would give you the right answer of 360, subtract 360 from the result and you get the answer...