[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： oCi=4#g%7  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); NufLzg{  
net.trainParam.show = 50; %K`% *D
  
net.trainParam.lr = 0.05; LbG_z =A  
net.trainParam.epochs = 300; Q/I!}C4  
net.trainParam.goal = 1e-5; ? glSC$b  
p = [-1 -1 2 2;0 5 0 5]; #iWSDy  
t = [-1 -1 1 1]; P%=#^T&`}  
net=train(net,p,t); 2f:Eof(B  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 :Jy'#c  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 4EZ9hA9+  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 tqeZ#w7  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 7L@K _ZJ  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 ;A'Z4=*~  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 x~{;TZa[I  
TRAINGD, Performance goal met. kRD%b[*d  
a = sim(net,p) 2Sp=rI  
plot(p,t,p,a,'o') Eu-RNrYh#  
但是为什么老是报错： D <&X_  
??? Input argument "net" is undefined. {R61cD,n