[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： uW;Uq=UN  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); a[s%2>e  
net.trainParam.show = 50; Cd#*Wp)s  
net.trainParam.lr = 0.05; vJGxD\h  
net.trainParam.epochs = 300; i#lvt#2J0  
net.trainParam.goal = 1e-5; PGT!HdX#{  
p = [-1 -1 2 2;0 5 0 5]; SrK;b .  
t = [-1 -1 1 1]; L3q)j\ls  
net=train(net,p,t); e^~t52]  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 $qQ6u!  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 (#c5Q&  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 0x# 6L  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 ] >ipC,v  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 &:]_a?|*S  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 oZ6xHdPc4  
TRAINGD, Performance goal met. pRc(>P3;  
a = sim(net,p) 6z%3l7#7Yi  
plot(p,t,p,a,'o') r_)-NOp  
但是为什么老是报错： NL&g/4A[a  
??? Input argument "net" is undefined. R$,`}@VqZ3