[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： | .+P ;g  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); W[jg+|  
net.trainParam.show = 50; jTwSyW  
net.trainParam.lr = 0.05; qkfof{z  
net.trainParam.epochs = 300; @<K<"`~H  
net.trainParam.goal = 1e-5; CC^D4]ug  
p = [-1 -1 2 2;0 5 0 5]; \d
:Q%S  
t = [-1 -1 1 1]; xxGm T.&  
net=train(net,p,t); yBK$2to~  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 s:{[Y7\?  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 zFOtOz`9H  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 [Or1  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 .BxI~d^  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 #8jiz+1 _  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 i,^-9  
TRAINGD, Performance goal met. zd$'8/Cq  
a = sim(net,p) #>yOp
*  
plot(p,t,p,a,'o') A^lm0[3q  
但是为什么老是报错： x|Uwk=;X|s  
??? Input argument "net" is undefined. |kmP#`P~