> NMSE=rep(0,5);NMSEO=NMSE
>for(i in 1:5){
+ m=zz1[zz2==i]
+ a<-lm(订单~.,data=w)
+ y0=predict(a,w[-m,]);y1=predict(a,w[m,])
+ NMSEO(i)=mean((w$订单[-m]-y0)^2)/mean((w$订单[-m]-mean(w$订单[-m]))^2)
+ NMSE[i]=mean((w$订单[m]-y1)^2)/mean((w$订单[m]-mean(w$订单[m]))^2)}
Error: object 'zz1' not found
> (MNMSE)=mean(NMSE0));(MNMSE=mean(NMSE))
Error: unexpected ')' in "(MNMSE)=mean(NMSE0))"