怎样使用matlab,利用最小二乘法得到回归方程

定义函数文件myfun。m
function yhat = myfun(beta,x)
b1 = beta(1);
b2 = beta(2);
b3 = beta(3);
b4 = beta(4);
b5 = beta(5);
b6 = beta(6);
b7 = beta(7);
b8 = beta(8);
b9 = beta(9);
b10 = beta(10);
x1 = x(:,1);
x2 = x(:,2);
x3 = x(:,3);
yhat = b1+b2*x1+b3*x2+b4*x3+b5*x1。*x2+b6*x2。*x3+b7*x1。*x3+b8*x1。^2+b9*x2。^2+b10*x3。^2;
在命令窗口输入
x1=[0。4,0。4,0。4,0。4,0。2,0。2,0。2,0。2,0。4,0。4,0。4,0。4,0。2,0。2,0。2,0。2,0。3,0。3,0。1,0。5,0。3,0。3,0。3,0。3,0。3,0。3,0。3,0。3,0。3,0。3,0。3];
x2=[0。08,0。08,0。04,0。04,0。08,0。08,0。04,0。04,0。08,0。08,0。04,0。04,0。08,0。08,0。04,0。04,0。06,0。06,0。06,0。06,0。02,0。1,0。06,0。06,0。06,0。06,0。06,0。06,0。06,0。06,0。06];
x3=[350,250,350,250,350,250,350,250,350,250,350,250,350,250,350,250,300,300,300,300,300,300,200,400,300,300,300,300,300,300,300];
y=[0。99539,1。0313,0。88595,0。92168,0。30154,0。32745,0。21272,0。24863,0。94551,0。96347,0。95656,0。97452,0。20773,0。21549,0。20928,0。23716,0。48393,0。53528,0。18166,1。56209,0。48072,0。54849,0。54154,0。48767,0。50432,0。52464,0。52637,0。51482,0。50425,0。50603,0。51446];
x=[x1' x2' x3'];
y=y';
beta = nlinfit(x,y,@myfun,ones(1,10))