On Aug 31, 2011, at 11:45 AM, zhenjiang xu wrote:
> Hi R users,
>
> suppose I have two vectors,
>> x=c(1,2,3,4,5)
>> y=c('a','b','c','a','c')
> How can I get a data.frame like this?
>> xy
> count
> a 5
> b 2
> c 8
>
> I know a few ways to fulfill the task. However, I have a huge number
> of this kind calculations, so I'd like an efficient solution. Thanks
See ?rep and ?as.data.frame.table
Try this:
> data.frame(table(rep(y, x)))
Var1 Freq
1 a 5
2 b 2
3 c 8
HTH,
Marc Schwartz
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