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;