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+++ b/Supporting Functions/MedianFrequency.m
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+function [MedFreq,errormsg] = MedianFrequency(xV,leftcutoff,rightcutoff)
+% [MedFreq,errormsg] = MedianFrequency(xV,leftcutoff,rightcutoff)
+% MEDIANFREQUENCY computes the median frequency in a frequency range given 
+% by 'leftcutoff' and 'rightcuroff' for a given time series 'xV'. 
+% The standard periodogram is called to compute the power spectrum assuming 
+% frequency=1, so that the largest frequency the power spectrum is computed 
+% for is 0.5 if 'rightcuroff' is specified. The lower frequency is given 
+% by 'leftcutoff' or 0 if 'leftcutoff' is not specified. The frequency 
+% resolution is given by the length of the time series. 
+% INPUT 
+% - xV      : the given time series
+% - leftcutoff: the left cutoff of frequency (to avoid the effect of drifts 
+%               in the signal).
+% - rightcutoff: the right cutoff of frequency (to avoid the effect of  
+%                high frequency elements in the signal).
+% OUTPUT
+% - MedFreq : The median frequency
+% - errormsg: a string of error message in case output cannot be generated.
+%========================================================================
+%     <MedianFrequency.m>, v 1.0 2010/02/11 22:09:14  Kugiumtzis & Tsimpiris
+%     This is part of the MATS-Toolkit http://eeganalysis.web.auth.gr/
+
+%========================================================================
+% Copyright (C) 2010 by Dimitris Kugiumtzis and Alkiviadis Tsimpiris 
+%                       <dkugiu@gen.auth.gr>
+
+%========================================================================
+% Version: 1.0
+
+% LICENSE:
+%     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
+%     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/>.
+
+%=========================================================================
+% Reference : D. Kugiumtzis and A. Tsimpiris, "Measures of Analysis of Time Series (MATS): 
+% 	          A Matlab  Toolkit for Computation of Multiple Measures on Time Series Data Bases",
+%             Journal of Statistical Software, in press, 2010
+
+% Link      : http://eeganalysis.web.auth.gr/
+%========================================================================= 
+if nargin==2
+    rightcutoff = 0.5;
+elseif nargin==1
+    rightcutoff = 0.5;
+    leftcutoff = 0.0;
+end
+errormsg = [];
+[psV,freqV]=periodogram(xV); 
+MedFreq = [];
+if length((find(isnan(psV))))==0
+    d=length(psV(find(freqV<leftcutoff)));
+    op=find(cumsum(psV(find(freqV>=leftcutoff)))>0.5*sum(psV(find(freqV>=leftcutoff & freqV<=rightcutoff))));
+    if length(op)>0
+        MedFreq=freqV(op(1)+d);
+    end
+else
+    errormsg = 'The periodogram could not be computed or cutoff values are not proper.';
+end