[求助]新手求助~（关于初级的神经网络问题） [复制链接]

各位大虾，我在网上看到的教程里的一个程序段，本来想要试试看的： <b$.{&K  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); .P5OUK  
net.trainParam.show = 50; T99\R%  
net.trainParam.lr = 0.05; J2d3&6  
net.trainParam.epochs = 300; +JrbC/&  
net.trainParam.goal = 1e-5; z)&ZoSXWc  
p = [-1 -1 2 2;0 5 0 5]; N!iugGL  
t = [-1 -1 1 1]; /Dk`vn2eN  
net=train(net,p,t); N497"H</  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 o1?bqVF;6  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 9E-]S'Z  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 ?KMGk]
_<  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 ]p5]n*0X  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 VYC$Q;Z  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 mO(A'p "b  
TRAINGD, Performance goal met.
Os>^z@x  
a = sim(net,p) L92vb zP  
plot(p,t,p,a,'o') C6ry]R@  
但是为什么老是报错： QssU\@/Q  
??? Input argument "net" is undefined. FhVoN}