circ_stats

 stats = circ_stats(alpha, w)
   Computes descriptive statistics for circular data.

   Input:
     alpha   sample of angles in radians
     [w      weightings in case of binned angle data]
     [d    spacing of bin centers for binned data, if supplied 
           correction factor is used to correct for bias in 
           estimation of r]

   Output:
     stats   structure containing descriptive statistics

 References:
   Statistical analysis of circular data, N. I. Fisher
   Topics in circular statistics, S. R. Jammalamadaka et al. 
   Biostatistical Analysis, J. H. Zar

 Circular Statistics Toolbox for Matlab

0001 function stats = circ_stats(alpha, w, d)
0002 %
0003 % stats = circ_stats(alpha, w)
0004 %   Computes descriptive statistics for circular data.
0005 %
0006 %   Input:
0007 %     alpha   sample of angles in radians
0008 %     [w      weightings in case of binned angle data]
0009 %     [d    spacing of bin centers for binned data, if supplied
0010 %           correction factor is used to correct for bias in
0011 %           estimation of r]
0012 %
0013 %   Output:
0014 %     stats   structure containing descriptive statistics
0015 %
0016 % References:
0017 %   Statistical analysis of circular data, N. I. Fisher
0018 %   Topics in circular statistics, S. R. Jammalamadaka et al.
0019 %   Biostatistical Analysis, J. H. Zar
0020 %
0021 % Circular Statistics Toolbox for Matlab
0022 
0023 % By Philipp Berens, 2009
0024 % berens@tuebingen.mpg.de
0025 
0026 alpha = alpha(:);
0027 if nargin<2
0028   w = ones(size(alpha));
0029 end
0030 
0031 if nargin < 3
0032   d = 0;
0033 end
0034 
0035 % mean
0036 stats.mean = circ_mean(alpha,w);
0037 
0038 % median
0039 if sum(w)==length(alpha)
0040   if numel(alpha) > 1000
0041     idx = randperm(numel(alpha));
0042     idx = idx(1:1000);
0043   else
0044     idx = 1:numel(alpha);
0045   end
0046   stats.median = circ_median(alpha(idx));
0047 else
0048   stats.median = NaN;
0049 end
0050 
0051 % variance
0052 stats.var = circ_var(alpha,w,d);
0053 
0054 % standard deviation
0055 [stats.std stats.std0] = circ_std(alpha,w,d);
0056 
0057 
0058 % skewness
0059 [stats.skewness stats.skewness0] = circ_skewness(alpha,w);
0060 
0061 % kurtosis
0062 [stats.kurtosis stats.kurtosis0] = circ_kurtosis(alpha,w);
0063 
0064 
0065 
0066