[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： p$NQyS5C"S  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); z0p*Z&  
net.trainParam.show = 50; +,TRfP Fb  
net.trainParam.lr = 0.05; nJG U-Z  
net.trainParam.epochs = 300; M=.n7RY-  
net.trainParam.goal = 1e-5; */)c?)"  
p = [-1 -1 2 2;0 5 0 5]; W#4 7h7M  
t = [-1 -1 1 1]; \=?a/  
net=train(net,p,t); +qtJaYf/0  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 dUeN*Nq&(,  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 53;}Nt#R  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 ]_mb7X>  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 b,l$1{  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 {3>$[bT  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 F 5bj=mI  
TRAINGD, Performance goal met. V%7WUq  
a = sim(net,p) #l\=}#\1Wb  
plot(p,t,p,a,'o') &Cq`Y !y  
但是为什么老是报错： :}L[sl\R  
??? Input argument "net" is undefined. $B2J T9