[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： EAjo>GLI  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); &b&o];a  
net.trainParam.show = 50; S~ 3|  
net.trainParam.lr = 0.05; T2MX_rt#D  
net.trainParam.epochs = 300; t9 m],aH  
net.trainParam.goal = 1e-5; QYTwGThWR  
p = [-1 -1 2 2;0 5 0 5]; 1_.#'U>  
t = [-1 -1 1 1]; %epK-q9[  
net=train(net,p,t); R|H_F#eVn}  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 4Vi&Y')f  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 b`sph%&  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 QabYkL
5@  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 *d/]-JN,K  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 [M6/?4\  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 ? /Z hu  
TRAINGD, Performance goal met. ;F<)BEXC<  
a = sim(net,p) 7'xds  
plot(p,t,p,a,'o') OT5'cl  
但是为什么老是报错： k)R>5?_  
??? Input argument "net" is undefined. F I\V6\B/