[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： I$ ?.9&.&  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); @h%Nn)QBq  
net.trainParam.show = 50; 
{Ok]$0L  
net.trainParam.lr = 0.05; "8\2w]"  
net.trainParam.epochs = 300; CS;4ysNf  
net.trainParam.goal = 1e-5; =DXN`]uN  
p = [-1 -1 2 2;0 5 0 5];
mv#*%St5  
t = [-1 -1 1 1]; rouaT  
net=train(net,p,t); Bh65qHQO  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 +EH"A  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 .i3_D??  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 G54`{V4&s  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 a-NicjV#  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 Am"&ApK  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 8Q73h/3  
TRAINGD, Performance goal met. !WTL:dk  
a = sim(net,p) Lv<vMIr  
plot(p,t,p,a,'o') SnY{|  
但是为什么老是报错： {vp*m:K  
??? Input argument "net" is undefined. rw[Ioyr-