DFA(Detrended fluctuation analysis) matlab 程序

%导入演示数据 load data %设置时间 t=1:0.05:3; n=zeros(1,length(t)); for i=1:length(t) n(i)=10^t(i); end n=floor(n); n=n'; %初始化 len=length(n); F_n=zeros(len,1); %对每个n值求F_n for i=1:len F_n(i)=DFA(data,n(i),1); end %线性拟合 p=polyfit(log10(n),log10(F_n),1); %画图 plot(n,F_n(:,1),'o'); %画拟合直线 x=n; y=p(2)+p(1)*log10(x); for i=1:len y(i)=10^y(i); end hold on plot(x,y,'black'); %设置坐标 axis([8 1200 0.003 0.5]) set(gca,'XSCALE','log'); set(gca,'YSCALE','log'); xlabel('n','FontSize',16,'FontAngle','Italic') ylabel('F(n)','FontSize',16,'FontAngle','Italic') %添加文字 str=['$$F(n)=' num2str(10^p(2)) ' \times n^{' num2str(p(1)) '}$$'] text('Interpreter','latex','String',str,'Position',[50 0.01],'FontSize',16) hold off