[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： h1H$3TpP  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); Y2IMHNtH  
net.trainParam.show = 50; T`bUBrK6g`  
net.trainParam.lr = 0.05; vb| d  
net.trainParam.epochs = 300; f/QwXO-U  
net.trainParam.goal = 1e-5; -'F27])  
p = [-1 -1 2 2;0 5 0 5]; gF
d*\Dk  
t = [-1 -1 1 1]; 8|(],NyEJ  
net=train(net,p,t); i;atYltEJ2  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 CZE!@1"<{  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 5Bt~tt  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 jgiS/oW  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 +eO>> ~Z  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 (_]!}N  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 ~0h@p4  
TRAINGD, Performance goal met. _K&Hiz/'  
a = sim(net,p) rog1  
plot(p,t,p,a,'o') qyAn
q%B}  
但是为什么老是报错： 5KfrkZ  
??? Input argument "net" is undefined. G3 |x%/Fbp