clear allclcformat longload 11.001xdata(1,:)=X11;load 11.002xdata(2,:)=X11;load 11.003;xdata(3,:)=X11;load 11.004xdata(4,:)=X11;    % aa=[1 2 3 5;2 4 5 1;3 5 6 2];% b=[2 3 4 5];% aa(1,:)./b% yy=fft(acc(1,:))% mean_colum=sum(xdata)/4;mean_colum=mean(xdata);xxdata=xdata-ones(4,1)*mean_colum; xxdata=xxdata.^2;ss=sqrt(sum(xxdata)/4);for k=1:4xxdata(k,:)=xdata(k,:)./ss;end for n=1:40for k=1:200    m=(n-1)*200;    xx(:,k)=xxdata(:,k+m);    end covarianceMatrix=xx'*xx/3;% covarianceMatrix = cov(xx,1);  [E,D] = eig(covarianceMatrix);  % D end  A=xx(1,:)*E; for k=197:200A1(k-196)=A(k);P1(:,k-196)=E(:,k); end r_xdata=A1*P1'; for k=1:200 r_xdata(1,k)*ss(7800+k)+mean_colum(7800+k); end t=1:200 plot(t,r_xdata)% covarianceMatrix = cov(xx,1);    %計算協(xié)方差矩陣[E,D] = eig(covarianceMatrix);          %計算協(xié)方差矩陣的特征值和特征向量