[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： B_FfXFQm<  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); "yR5
6`=  
net.trainParam.show = 50; Wsb=SM7;  
net.trainParam.lr = 0.05; $y!k)"k  
net.trainParam.epochs = 300; {I s?>m4  
net.trainParam.goal = 1e-5; zV)Ob0M7U  
p = [-1 -1 2 2;0 5 0 5]; ?!H<V@a  
t = [-1 -1 1 1]; S>~QuCMY  
net=train(net,p,t); 7 4rmxjiN  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 8Z;wF  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 8i!~w 7z  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 L@*0wx`fU  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 yteJHaq  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 Hu$]V*rAG  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 D:Zpls.  
TRAINGD, Performance goal met. MF>1u%  
a = sim(net,p) #4h_(Y  
plot(p,t,p,a,'o') :[gM 5G  
但是为什么老是报错： Q1qf'u
 
??? Input argument "net" is undefined. -#]?3*NO