--- /dev/null
+function [i,v,m] = zscore(i,DIM)
+% ZSCORE removes the mean and normalizes the data
+% to a variance of 1. Can be used for Pre-Whitening of the data, too.
+%
+% [z,r,m] = zscore(x,DIM)
+% z z-score of x along dimension DIM
+% r is the inverse of the standard deviation
+% m is the mean of x
+%
+% The data x can be reconstrated with
+% x = z*diag(1./r) + repmat(m,size(z)./size(m))
+% z = x*diag(r) - repmat(m.*v,size(z)./size(m))
+%
+% DIM dimension
+% 1: STATS of columns
+% 2: STATS of rows
+% default or []: first DIMENSION, with more than 1 element
+%
+% see also: SUMSKIPNAN, MEAN, STD, DETREND
+%
+% REFERENCE(S):
+% [1] http://mathworld.wolfram.com/z-Score.html
+
+% 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 2 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/>.
+
+
+% $Id: zscore.m 8223 2011-04-20 09:16:06Z schloegl $
+% Copyright (C) 2000-2003,2009 by Alois Schloegl <alois.schloegl@gmail.com>
+% This function is part of the NaN-toolbox
+% http://pub.ist.ac.at/~schloegl/matlab/NaN/
+
+
+if any(size(i)==0); return; end;
+
+if nargin<2
+ DIM=[];
+end
+if nargin<3
+ W = [];
+end
+if isempty(DIM),
+ DIM=min(find(size(i)>1));
+ if isempty(DIM), DIM=1; end;
+end;
+
+
+% pre-whitening
+m = mean(i,DIM,W);
+i = i-repmat(m,size(i)./size(m)); % remove mean
+v = 1./sqrt(mean(i.^2,DIM,W));
+i = i.*repmat(v,size(i)./size(v)); % scale to var=1
+
+
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