[R] How to get duplicated items in a vector?

jim holtman jholtman at gmail.com
Fri Oct 2 13:56:58 CEST 2009


Try this:

>  x=c(rep(1,3),rep(3,2))
> x
[1] 1 1 1 3 3
> duplicated(x) | duplicated(x, fromLast=TRUE)
[1] TRUE TRUE TRUE TRUE TRUE
>


On Thu, Oct 1, 2009 at 10:42 PM, Peng Yu <pengyu.ut at gmail.com> wrote:
> Hi,
>
>> x=c(rep(1,3),rep(3,2))
>> x
> [1] 1 1 1 3 3
>> duplicated(x)
> [1] FALSE  TRUE  TRUE FALSE  TRUE
>>
>
> As shown in the above code, 'duplicated' doesn't return 'F' for the
> first '1' and first '3' in 'x'. I am wondering if there is a function
> that can return an indicator for any element whether it appears in a
> vector twice or more.
>
> Regards,
> Peng
>
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>



-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?




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