huigui.txt

一元线性回归分析的源码

xx=[3496.2 4283.0 4838.9 5160.3 5425.1 5854.0 6280.0 6859.6 7702.8 8472.2 9421.6 10493.0]; 
yy=[2851.3 3538.0 3919.5 4186.0 4331.6 4615.9 4998.0 5309.0 6030.0 6511.0 7182.0 7943.0]; 
[x,index]=sort(xx) 
y=yy(index) 
[c,s]=polyfit(x,y,1); 
[yhat,w]=polyconf(c,x,s,.05); 
sxx=sum(x.^2)-length(x)*mean(x)^2; 
syy=sum(y.^2)-length(x)*mean(y)^2; 
sxy=sum(x.*y)-length(x)*mean(x)*mean(y);
b=sxy/sxx
a=mean(y)-b*mean(x)
r2=(syy-b*sxy)/(12-2)
t0=b*sqrt(sxx)/sqrt(r2)
plot(x,yhat,'k-',x,yhat-w,'k--',x,yhat+w,'k--',x,y,'ks',[x;x],[yhat;y],'k-')
legend('Regression line','95% confidence of y',4) 
axis([3000 11000 2000 9000]) 
xlabel('x(input)') 
ylabel('y(reponse)') 
title('simple linear regression')