[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： 9:9N)cNvfX  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); SZim>@R  
net.trainParam.show = 50; 1R'u v4e  
net.trainParam.lr = 0.05; aW`:)y&f  
net.trainParam.epochs = 300; _XH4;uGg  
net.trainParam.goal = 1e-5; pgz:F#>  
p = [-1 -1 2 2;0 5 0 5]; w|!YoMk+o  
t = [-1 -1 1 1]; g:3d<CS  
net=train(net,p,t); P[Y{LKAbb  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 iwG>]:K3  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 86;+r'3p.  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 u"`5  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 N`,7FI}  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 =F'l's^j  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 4c5^7";P  
TRAINGD, Performance goal met. ;=5@h!@R  
a = sim(net,p) ONjC(7  
plot(p,t,p,a,'o') %+AS0 Jh
B  
但是为什么老是报错： 8BYIxHHz  
??? Input argument "net" is undefined. egZyng pB