[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： =JEnK_@?K\  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd');  ) .#,1
 
net.trainParam.show = 50; mjH8q&szf  
net.trainParam.lr = 0.05; ^D6JckW  
net.trainParam.epochs = 300; HeR-;L  
net.trainParam.goal = 1e-5; }-Zfljj  
p = [-1 -1 2 2;0 5 0 5]; ,g/UPK8K=  
t = [-1 -1 1 1]; !5[?n3  
net=train(net,p,t); <FGM/e4  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 }G-qOt  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 B-Fu/
n  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 $H-s(3vq  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 _hXadLt  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 -BB5bsjA  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 JP[BSmhAV  
TRAINGD, Performance goal met. qA*
QFQ'-  
a = sim(net,p) ,Kdvt@vle  
plot(p,t,p,a,'o') Q%@l`V)Rs  
但是为什么老是报错： KaO8rwzDN  
??? Input argument "net" is undefined. om@` NW