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Message-ID: <633509595.5638722.1457398041789.JavaMail.yahoo@mail.yahoo.com>
Date: 2016-03-08T00:47:21Z
From: Mohammad Tanvir Ahamed
Subject: Extract every 2 element for a list which are not equal in length

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 
G?teborg, Sweden  |  mashranga at yahoo.com