Adding NA so that all list items are equal in length

Question

I am doing a series of things in dplyr , tidyr , so if possible I would like to support the solution across the channels.

I have a list with unequal numbers of elements in each component:

 lolz <- list(a = c(2,4,5,2,3), b = c(3,3,2), c=c(1,1,2,4,5,3,3), d=c(1,2,3,1), e=c(5,4,2,2)) lolz $a [1] 2 4 5 2 3 $b [1] 3 3 2 $c [1] 1 1 2 4 5 3 3 $d [1] 1 2 3 1 $e [1] 5 4 2 2 

I am wondering if there is a neat one liner to fill each element with NA so that they all have the same length as the element with maximum elements:

I have 2 liner:

 lolz %>% lapply(length) %>% unlist %>% max -> mymax lolz %>% lapply(function(x) c(x, rep(NA, mymax-length(x)))) $a [1] 2 4 5 2 3 NA NA $b [1] 3 3 2 NA NA NA NA $c [1] 1 1 2 4 5 3 3 $d [1] 1 2 3 1 NA NA NA $e [1] 5 4 2 2 NA NA NA 

I wonder if I miss something faster / more elegant.

Answer 1

you can use

 lapply(lolz, `length<-`, max(lengths(lolz))) # $a # [1] 2 4 5 2 3 NA NA # # $b # [1] 3 3 2 NA NA NA NA # # $c # [1] 1 1 2 4 5 3 3 # # $d # [1] 1 2 3 1 NA NA NA # # $e # [1] 5 4 2 2 NA NA NA 

or

 n <- max(lengths(lolz)) lapply(lolz, `length<-`, n)