[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： W&Y4Dq^  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); So0`c,D  
net.trainParam.show = 50; twAw01".  
net.trainParam.lr = 0.05; 4 3}qaf[  
net.trainParam.epochs = 300; bn5"dxV  
net.trainParam.goal = 1e-5; FW/6{tm  
p = [-1 -1 2 2;0 5 0 5]; %L.lkR
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t = [-1 -1 1 1]; (2n3exx  
net=train(net,p,t); N45s'rF  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 (q055y  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 #d3[uF]OmW  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 )kFme=;  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 }ZxW"5oq  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 *sIi$1vHu  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 v\J!yz  
TRAINGD, Performance goal met. 7$;c6_se  
a = sim(net,p) ;]|m((15G  
plot(p,t,p,a,'o') u!sSgx=  
但是为什么老是报错： /M5=tW#e  
??? Input argument "net" is undefined. ]
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