[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： *7Sg8\wDn  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd');
S4O:?^28  
net.trainParam.show = 50; ,/L_9wV-\  
net.trainParam.lr = 0.05; 9.goO|~B~  
net.trainParam.epochs = 300; MD:kfPQ  
net.trainParam.goal = 1e-5; L3Q1az!Ct  
p = [-1 -1 2 2;0 5 0 5]; qj|B #dU  
t = [-1 -1 1 1]; ,TO&KO1;&  
net=train(net,p,t); cmh/a~vYaY  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 .+AO3~Dg  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 m4P=,=%  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 PzTTL=G +  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 }Lwj~{  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 13{"sY:PT#  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 ;lWy?53=@  
TRAINGD, Performance goal met. @p2dXJeR<  
a = sim(net,p) ;v+CQx  
plot(p,t,p,a,'o') M/sqOhg  
但是为什么老是报错： {_MU0=7c\  
??? Input argument "net" is undefined. WU,72g=