load CEOSAL1.txt; %录入数据
y = CEOSAL1(:,1); %取出数据第一列
x = CEOSAL1(:,4); %取出数据第四列
xvar = [ones(length(CEOSAL1),1) x]; %生成自变量矩阵
i = ones(length(CEOSAL1),1); %生成一列1
I = eye(length(CEOSAL1)); %生成单位阵
m0 = I - i*i'*1/length(CEOSAL1);
SST = y'*m0*y;
xpx=((xvar)'*(xvar));
xpxinv=inv(xpx);
bhat=xpxinv*xvar'*y;
e = y - xvar*bhat;
SSR=e'*e;
Rsqure=1-SSR/SST
bhat=xpxinv*xvar'*y
gscatter(x,y)
hold on;
x=0:0.5:60;
y=bhat(1,:)+bhat(2,:)*x;
plot(x,y)
hold off;