[R] matching element of a vector to i-2nd element

[Bert Gunter]

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Cheers,
Bert
Bert Gunter

"The trouble with having an open mind is that people keep coming along
and sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Sun, Jul 23, 2017 at 11:43 AM, Davide Piffer <pifferdavide at gmail.com> wrote:
> I have a df with a vector v. For each element of the vector, I want to
> know whether the i-2nd element is the same as the ith element. For
> example:
> given
> v=c(A,C,D,C) the result should be:
> FALSE,FALSE,FALSE,TRUE.
>
> I attempted something using indexing in a for loop such as (bad,
> incorrect example):
>  for (i in v){
>   if [i]==[i-2] print T
> else print F
> }
>
> However, this is obviously wrong.
> Can someone provide a nice way to solve this?
>
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