[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
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net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); SVqKG+{My  
net.trainParam.show = 50; <L:}u!  
net.trainParam.lr = 0.05; eRB K= X  
net.trainParam.epochs = 300; K# BZ Jcb  
net.trainParam.goal = 1e-5; h:{^&d a  
p = [-1 -1 2 2;0 5 0 5]; N.q0D5 :  
t = [-1 -1 1 1]; =|
_k a8{?  
net=train(net,p,t); I4MZJAYk  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 /e]R0NI  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 i} ?\K>BWq  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 P7 R}oO_n:  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 e+Sq&H!@  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 koy0A/\%  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 3'6by!N,d  
TRAINGD, Performance goal met. VMJK9|JC[  
a = sim(net,p) 8W}rSv+  
plot(p,t,p,a,'o') cb%ML1c  
但是为什么老是报错： o3a%u
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??? Input argument "net" is undefined. M`Q
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