[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： O?0`QMY  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); (
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net.trainParam.show = 50; IQQ>0^Q~  
net.trainParam.lr = 0.05; IHv>V9yiG  
net.trainParam.epochs = 300; <=%=,Yk  
net.trainParam.goal = 1e-5; ZhFlR*EQ  
p = [-1 -1 2 2;0 5 0 5]; >,x``-  
t = [-1 -1 1 1]; pYh\l.@qf  
net=train(net,p,t); f@0Km^aUc  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 5=Il2  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 |Q$Dj!!1P  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 84/#,X!=s  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 @PV3G KJ  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 fvRqt)Ks  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 |xrnLdng0R  
TRAINGD, Performance goal met. iN
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a = sim(net,p) ''}2JJU{  
plot(p,t,p,a,'o') ,8o Y(h  
但是为什么老是报错： "] ]aF1  
??? Input argument "net" is undefined. o\X|\nUk