--- /dev/null
+function [varargout]=statistic(i,DIM,fun)
+% STATISTIC estimates various statistics at once.
+%
+% R = STATISTIC(x,DIM)
+% calculates all statistic (see list of fun) in dimension DIM
+% R is a struct with all statistics
+%
+% y = STATISTIC(x,fun)
+% estimate of fun on dimension DIM
+% y gives the statistic of fun
+%
+% DIM dimension
+% 1: STATS of columns
+% 2: STATS of rows
+% N: STATS of N-th dimension
+% default or []: first DIMENSION, with more than 1 element
+%
+% fun 'mean' mean
+% 'std' standard deviation
+% 'var' variance
+% 'sem' standard error of the mean
+% 'rms' root mean square
+% 'meansq' mean of squares
+% 'sum' sum
+% 'sumsq' sum of squares
+% 'CM#' central moment of order #
+% 'skewness' skewness
+% 'kurtosis' excess coefficient (Fisher kurtosis)
+% 'mad' mean absolute deviation
+%
+% features:
+% - can deal with NaN's (missing values)
+% - dimension argument
+% - compatible to Matlab and Octave
+%
+% see also: SUMSKIPNAN
+%
+% REFERENCE(S):
+% [1] http://www.itl.nist.gov/
+% [2] http://mathworld.wolfram.com/
+
+% $Id: statistic.m 8223 2011-04-20 09:16:06Z schloegl $
+% Copyright (C) 2000-2003,2010 by Alois Schloegl <alois.schloegl@gmail.com>
+% This function is part of the NaN-toolbox
+% http://pub.ist.ac.at/~schloegl/matlab/NaN/
+
+% This program is free software; you can redistribute it and/or modify
+% it under the terms of the GNU General Public License as published by
+% the Free Software Foundation; either version 3 of the License, or
+% (at your option) any later version.
+%
+% This program is distributed in the hope that it will be useful,
+% but WITHOUT ANY WARRANTY; without even the implied warranty of
+% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+% GNU General Public License for more details.
+%
+% You should have received a copy of the GNU General Public License
+% along with this program; If not, see <http://www.gnu.org/licenses/>.
+
+
+
+if nargin==1,
+ DIM=[];
+ fun=[];
+elseif nargin==2,
+ if ~isnumeric(DIM),
+ fun=DIM;
+ DIM=[];
+ else
+ fun=[];
+ end
+end
+if isempty(DIM),
+ DIM = find(size(i)>1,1);
+ if isempty(DIM), DIM=1; end;
+end;
+
+%R.N = sumskipnan(~isnan(i),DIM); % number of elements
+[R.SUM,R.N,R.SSQ] = sumskipnan(i,DIM); % sum
+%R.S3P = sumskipnan(i.^3,DIM); % sum of 3rd power
+R.S4P = sumskipnan(i.^4,DIM); % sum of 4th power
+%R.S5P = sumskipnan(i.^5,DIM); % sum of 5th power
+
+R.MEAN = R.SUM./R.N; % mean
+R.MSQ = R.SSQ./R.N; % mean square
+R.RMS = sqrt(R.MSQ); % root mean square
+%R.SSQ0 = R.SSQ-R.SUM.*R.MEAN; % sum square of mean removed
+R.SSQ0 = R.SSQ - real(R.SUM).*real(R.MEAN) - imag(R.SUM).*imag(R.MEAN); % sum square of mean removed
+
+%if flag_implicit_unbiased_estim; %% ------- unbiased estimates -----------
+ n1 = max(R.N-1,0); % in case of n=0 and n=1, the (biased) variance, STD and SEM are INF
+%else
+% n1 = R.N;
+%end;
+
+R.VAR = R.SSQ0./n1; % variance (unbiased)
+R.STD = sqrt(R.VAR); % standard deviation
+R.SEM = sqrt(R.SSQ0./(R.N.*n1)); % standard error of the mean
+R.SEV = sqrt(n1.*(n1.*R.S4P./R.N+(R.N.^2-2*R.N+3).*(R.SSQ./R.N).^2)./(R.N.^3)); % standard error of the variance
+R.COEFFICIENT_OF_VARIATION = R.STD./R.MEAN;
+
+q = quantile(i, (1:3)/4, DIM);
+
+%sz=size(i);sz(DIM)=1;
+%Q0500=repmat(nan,sz);
+%Q0250=Q0500;
+%Q0750=Q0500;
+%MODE=Q0500;
+%for k=1:size(i,2),
+% tmp = sort(i(:,k));
+ %ix = find(~~diff([-inf;tmp;inf]))
+ %ix2=diff(ix)
+ %MODE(k)= tmp(max(ix2)==ix2)
+% Q0500(k) = flix(tmp,R.N(k)/2 + 0.5);
+% Q0250(k) = flix(tmp,R.N(k)/4 + 0.5);
+% Q0750(k) = flix(tmp,R.N(k)*3/4 + 0.5);
+%end;
+%R.MEDIAN = Q0500;
+%R.Quartiles = [Q0250; Q0750];
+
+%R.Skewness.Fisher = (R.CM3)./(R.STD.^3); %%% same as R.SKEWNESS
+
+%R.Skewness.Pearson_Mode = (R.MEAN-R.MODE)./R.STD;
+%R.Skewness.Pearson_coeff1 = (3*R.MEAN-R.MODE)./R.STD;
+%R.Skewness.Pearson_coeff2 = (3*R.MEAN-R.MEDIAN)./R.STD;
+%R.Skewness.Bowley = (Q0750+Q0250 - 2*Q0500)./(Q0750-Q0250); % quartile skewness coefficient
+
+R.CM2 = R.SSQ0./n1;
+szi = size(i); szm = [size(R.MEAN),1];
+i = i - repmat(R.MEAN,szi./szm(1:length(szi)));
+R.CM3 = sumskipnan(i.^3,DIM)./n1;
+R.CM4 = sumskipnan(i.^4,DIM)./n1;
+%R.CM5 = sumskipnan(i.^5,DIM)./n1;
+
+R.SKEWNESS = R.CM3./(R.STD.^3);
+R.KURTOSIS = R.CM4./(R.VAR.^2)-3;
+[R.MAD,N] = sumskipnan(abs(i),DIM); % mean absolute deviation
+R.MAD = R.MAD./n1;
+
+R.datatype = 'STAT Level 3';
+
+tmp = version;
+if 0, %str2num(tmp(1))*1000+str2num(tmp(3))*100+str2num(tmp(5:6))<2136,
+ % ###obsolete: was needed for Octave version < 2.1.36
+ if strcmp(fun(1:2),'CM')
+ oo = str2double(fun(3:length(fun)));
+ varargout = sumskipnan(i.^oo,DIM)./n1;
+ elseif isempty(fun)
+ varargout = R;
+ else
+ varargout = getfield(R,upper(fun));
+ end;
+else
+ if iscell(fun),
+ for k=1:length(fun),
+ if strcmp(fun{k}(1:2),'CM')
+ oo = str2double(fun{k}(3:length(fun{k})));
+ varargout{k} = sumskipnan(i.^oo,DIM)./n1;
+ else
+ varargout{k} = getfield(R,upper(fun{k}));
+ end;
+ end;
+ elseif ischar(fun),
+ if strcmp(fun(1:2),'CM')
+ oo = str2double(fun(3:length(fun)));
+ varargout{1} = sumskipnan(i.^oo,DIM)./n1;
+ else
+ varargout{1} = getfield(R,upper(fun));
+ end;
+ else
+ varargout{1} = R;
+ end;
+end;