function output1=DFA(DATA,win_length,order)
%Copyright (c) 2009, Guan Wenye
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       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;