[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： NK-}[!f  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); 1dD%a91  
net.trainParam.show = 50; F%L"Q>aHW  
net.trainParam.lr = 0.05; '[r:pwE  
net.trainParam.epochs = 300; c[J 2;"SP  
net.trainParam.goal = 1e-5; >$kFYb>~q  
p = [-1 -1 2 2;0 5 0 5]; d 6Y9D=O  
t = [-1 -1 1 1]; u`EK^\R  
net=train(net,p,t); \m
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TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 5REH`-  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 GS*O{u  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 58?WO}  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 $7X;FmlG&  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10  7]@M  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 I'D3~UIf  
TRAINGD, Performance goal met. Qfeu3AT  
a = sim(net,p) 6l|L/Z_6  
plot(p,t,p,a,'o') H28-;>
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但是为什么老是报错： Zn1((J7  
??? Input argument "net" is undefined. Z9mI%sC[(