[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： lN1zfM  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); NA3yd^sr  
net.trainParam.show = 50; C#r`oZS1  
net.trainParam.lr = 0.05; w}(xs)`num  
net.trainParam.epochs = 300; @DUdgPA  
net.trainParam.goal = 1e-5; -B4v1{An  
p = [-1 -1 2 2;0 5 0 5]; 3>jz3>v@  
t = [-1 -1 1 1]; 6Nl$&jL  
net=train(net,p,t); 2 G"p:iPp  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 L,D!T&B  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 h)<42Y  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 .i. |wY  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 +}Q4 g]M8  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10
=~arj  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 2;&13%@!  
TRAINGD, Performance goal met. z%AIv%  
a = sim(net,p) ,v6Jr3  
plot(p,t,p,a,'o') Wh<lmC50(
 
但是为什么老是报错： O%)9tFT  
??? Input argument "net" is undefined. tL
).f:?