[R] Extract every 2 element for a list which are not equal in length

[Jorge I Velez]

Dear Mohammad,
What's wrong with the result?
Best,
Jorge.-

On Monday, March 7, 2016, Mohammad Tanvir Ahamed via R-help <
r-help at r-project.org> wrote:

> Hi,
>
> a <- c(1:5)b <- c(1:3)
> c <- 1
> d <- 5
> e <- list(a,b,c,d)
>
> # To extract every 1st element
> lapply(e,"[[",1)
>
> ## Out-put
> [[1]]
> [1] 1
>
> [[2]]
> [1] 1
>
> [[3]]
> [1] 1
>
> [[4]]
> [1] 5
>
> #To extract every 2nd element (Need help in this case)
> lapply(e,"[[",2)
>
> ## Expected outcome
> [[1]]
> [1] 2
>
> [[2]]
> [1] 2
>
> [[3]]
> [1] NA
>
> [[4]]
> [1] NA
>
>
>
> Any help will be appreciated . Thanks
>
>
> Tanvir Ahamed
> Göteborg, Sweden  |  mashranga at yahoo.com <javascript:;>
>
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-- 
Sent from my phone. Please excuse my brevity and misspelling.

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