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Ryan

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16 Aug 2012 Circular Statistics Toolbox (Directional Statistics) Compute descriptive and inferential statistics for circular or directional data. Author: Philipp Berens

I haven't run through this toolbox yet, so I apologize if I am missing something with this question (I just glanced through the source code because I am interested in directional stats).

When you calculate the mean, the formula you use is:

% compute weighted sum of cos and sin of angles
r = w'*exp(1i*alpha);

% obtain mean by
mu = angle(r);

Now, correct me if I'm wrong, but this doesn't seem to calculate the average at all? It seems to me that here we are inputting a data array into the angle command, which will output the phase angle of each element of that array, not a singular mean.

Wouldn't a better way of calculating the average be to use atan2? Something like:

for i = 1:w
S(i) = sin(alpha(i));
C(i) = cos(alpha(i));
end

X = sum(S)*(1/w);
Y = sum(C)*(1/w);

mu = atan2(X,Y);

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