[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： zK.%tx}+=k  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); 5J!ncLNm{  
net.trainParam.show = 50; E__^>=  
net.trainParam.lr = 0.05; On%21L;JG  
net.trainParam.epochs = 300; Fw,'a  
net.trainParam.goal = 1e-5; i'Vrx(y3  
p = [-1 -1 2 2;0 5 0 5]; }{"a}zOl  
t = [-1 -1 1 1]; 
]pUf[^4  
net=train(net,p,t); /C)mx#h]  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 xXG-yh  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 S!
!
i  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 ap|7./yg  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 Y r3h=XY  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 &t.9^;(  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 >q+o MrU  
TRAINGD, Performance goal met. W 2/`O?  
a = sim(net,p) m$nT#@l5bH  
plot(p,t,p,a,'o') OO)m{5r,{  
但是为什么老是报错： kmHIU}Z  
??? Input argument "net" is undefined. bvyX(^I[q