matlab绘制带置信区间的线性回归图

本文档参考：https://www.mathworks.com/help/stats/polyconf.html

代码如下：

xdata = feat(:,1);% x值 替换自己的
ydata = bpt(:,1); % y值 替换自己的

degree = 2;		% Degree of the fit
alpha = 0.05;	% Significance level

[p,S] = polyfit(xdata,ydata,degree);
hdata = plot(xdata, ydata,'md','MarkerSize',5,'LineWidth',2);
hold on;

xfit = min(xdata):1:max(xdata);
yfit = polyval(p,xfit);
hfit = plot(xfit,yfit,'b-','LineWidth',2);
% Add prediction intervals to the plot.
[Y,DELTA] = polyconf(p,xfit,S,'alpha',alpha);
hconf = plot(xfit,Y+DELTA,'b--');
plot(xfit,Y-DELTA,'b--')
% Add a legend.
legend([hdata,hfit,hconf],'Data','Fit','95% Prediction Intervals')

效果如下：