r语言中,with,which用法的问题,
r语言中,with,which用法的问题,
b b b
[1] 101 102
> with(subset(recommendation[user==1,]),which(item==101))
[1] 1
> with(subset(recommendation[user==1,]),which(item==102))
[1] 3
> with(subset(recommendation[user==1,]),which(b%in%item))
[1] 1 2
应该输出1和3呀怎么是2