[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： XM\\Imw  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); VP1hocW  
net.trainParam.show = 50; 'Ix@<$~i3F  
net.trainParam.lr = 0.05; G
N_L"|#)=  
net.trainParam.epochs = 300; (2b${Q@V  
net.trainParam.goal = 1e-5; &2W"4SE]6  
p = [-1 -1 2 2;0 5 0 5]; YrL(4Nt8  
t = [-1 -1 1 1]; fw&*;az  
net=train(net,p,t); QT c{7&  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 GQ1/pys  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 b+~_/;Y9  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 T<*)Cdid  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10  xL15uWk-  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 vEI{AmogRx  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 Fip 5vrD  
TRAINGD, Performance goal met. fTj@/"a  
a = sim(net,p) znrO~OK  
plot(p,t,p,a,'o') O>DS%6/G  
但是为什么老是报错： Tx}Nr^  
??? Input argument "net" is undefined. sywuS