[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： >cSi/a,L  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); oO}>i0ax*  
net.trainParam.show = 50; iu+zw[f  
net.trainParam.lr = 0.05; ] +sSg=N7i  
net.trainParam.epochs = 300; @b>YkJDk  
net.trainParam.goal = 1e-5; ^$ZI>L0+  
p = [-1 -1 2 2;0 5 0 5]; ^S:cNRSW"  
t = [-1 -1 1 1]; )OS>9 kFH  
net=train(net,p,t); HK=CP0H  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 sL;z"N@PK  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 c@)pKi#W  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 YGi/]^Nba  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10
Fj36K6!#?  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 ejDCmD  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 Y|Nfwqz  
TRAINGD, Performance goal met. `mQP{od?"?  
a = sim(net,p) dW:w<{a!R  
plot(p,t,p,a,'o') oT$(<$&<  
但是为什么老是报错： &P{o{  
??? Input argument "net" is undefined. |q9,,i}!