[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： jZu">Eh,  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); 0UeDM*  
net.trainParam.show = 50; qepsR/0M  
net.trainParam.lr = 0.05; r+fR^hv  
net.trainParam.epochs = 300; rMIr&T  
net.trainParam.goal = 1e-5; bj4cW\b(  
p = [-1 -1 2 2;0 5 0 5]; _sIhQ8$:  
t = [-1 -1 1 1]; WJBi#(SY  
net=train(net,p,t); L6yRN>5aE  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 Szrr
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TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 *(@(9]B~  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 [{e[3b*M|  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 !0:uM)_k  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 9,=3D2x&  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 I#QBJ#  
TRAINGD, Performance goal met. k`Nc<nN8  
a = sim(net,p) AVyO5>w  
plot(p,t,p,a,'o') _?&$@c  
但是为什么老是报错： '"LrGvkZ  
??? Input argument "net" is undefined. Xk%92Pto