求：关于nlinfit函数的问题

zzl309

M 文件：
function yhat = mymodel1(beta, x)

yhat=(beta(1)+beta(2)*x(:,1)+beta(3)*x(:,2)+beta(4)*x(:,3)+beta(5)*x(:,4)+beta(6)*x(:,5)+beta(7)*x(:,1).*x(:,1)+beta(8)*x(:,2).*x(:,2)+beta(9)*x(:,3).*x(:,3)+beta(10)*x(:,4).*x(:,4)+beta(11)*x(:,5).*x(:,5)+beta(12)*x(:,1).*x(:,2)+beta(13)*x(:,1).*x(:,3)+beta(14)*x(:,1).*x(:,4)+beta(15)*x(:,1).*x(:,5)+beta(16)*x(:,2).*x(:,3)+beta(17)*x(:,2).*x(:,4)+beta(18)*x(:,2).*x(:,5)+beta(19)*x(:,3).*x(:,4)+beta(20)*x(:,3).*x(:,5)+beta(21)*x(:,4).*x(:,5));

命令：
x=[1,1,2,1,2;
1,2,1,4,4;
1,3,3,2,1;
1,4,4,3,3;
2,1,4,2,4;
2,2,3,3,2;
2,3,1,1,3;
2,4,2,4,1;
3,1,1,3,1;
3,2,2,2,3;
3,3,4,4,2;
3,4,3,1,4;
4,1,3,4,3;
4,2,4,1,1;
4,3,2,3,4;
4,4,1,2,2];

y=[0.1726,0.1604,0.0997,0.1132,0.1753,0.1130,0.1476,0.0772,0.1071,0.1528,0.1065,0.1567,0.1473,0.1135,0.1323,0.1301];

beta0=[0.01,0.01,0.01,0.01,0.01,0.01,0.01,0.01,0.01,0.01,0.01,0.01,0.01,0.01,0.01,0.01,0.01,0.01,0.01,0.01,0.01];

beta = nlinfit(x,y,'mymodel1',beta0)

结果：报错
??? Error using ==> nlinfit
MODELFUN should return a vector of fitted values the same length as Y.

请问问题出在哪里？


老是跳出些错误，所以都用最保险的写，方程式才会那么长
各位高手帮忙看下！

friendchj

把y改成列向量即可，即在y=……后加一行y=y';
仔细看一下nlinfit的参数输入格式要求

zzl309

好的，我试下，谢谢