[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： U#o5(mK  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); Hh/Z4`&yi  
net.trainParam.show = 50; bzz{ p1e  
net.trainParam.lr = 0.05; fS( )F*J  
net.trainParam.epochs = 300; $!+t2P@d.5  
net.trainParam.goal = 1e-5; auV'`PR  
p = [-1 -1 2 2;0 5 0 5]; c"vF i~Db  
t = [-1 -1 1 1]; Z*/*P4\  
net=train(net,p,t); =Mg/m'QI  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 x#mZSSd  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 /xK5%cE>B  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10
Yl65|=ne  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 k+(UpO=/*  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 1[QH68  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10  T?!&a0  
TRAINGD, Performance goal met. lX)RG*FlTC  
a = sim(net,p) "IOu$?  
plot(p,t,p,a,'o') %-zAV*>  
但是为什么老是报错： owYSR?aG  
??? Input argument "net" is undefined. E8-8E2i,