function output1=DFA(DATA,win_length,order)
%Copyright (c) 2009, Guan Wenye
%All rights reserved.
%
%Redistribution and use in source and binary forms, with or without
%modification, are permitted provided that the following conditions are
%met:
%
%    * Redistributions of source code must retain the above copyright
%      notice, this list of conditions and the following disclaimer.
%    * Redistributions in binary form must reproduce the above copyright
%      notice, this list of conditions and the following disclaimer in
%      the documentation and/or other materials provided with the distribution
%
%THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
%AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
%IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
%ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
%LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
%CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
%SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
%INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
%CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
%ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
%POSSIBILITY OF SUCH DAMAGE.



      
       N=length(DATA);   
       n=floor(N/win_length);
       N1=n*win_length;
       y=zeros(N1,1);
       Yn=zeros(N1,1);
       
       fitcoef=zeros(n,order+1);
            mean1=mean(DATA(1:N1));
       for i=1:N1
                
                y(i)=sum(DATA(1:i)-mean1);
            end
            y=y';
            for j=1:n
                fitcoef(j,:)=polyfit(1:win_length,y(((j-1)*win_length+1):j*win_length),order);
            end
            
            for j=1:n
                Yn(((j-1)*win_length+1):j*win_length)=polyval(fitcoef(j,:),1:win_length);
            end
            
            sum1=sum((y'-Yn).^2)/N1;
            sum1=sqrt(sum1);
            output1=sum1;
          
