R - shuffle a list preserving element sizes

list, r

Solution

you may try recreating a second list with the skeleton of the first, and fill it with all the elements of the first list, like this:

u<-unlist(l)
l2<-relist(u[sample(length(u))],skeleton=l)
> l2
[[1]]
[1] "F" "A" "O" "I" "S" "Q"

[[2]]
[1] "R" "P" "K" "F" "G"

[[3]]
 [1] "A" "N" "M" "J" "H" "G" "E" "B" "T" "C" "D" "L"

Hope this helps!

Problem

In R, I need an efficient solution to shuffle the elements contained within a list, preserving the total number of elements, and the local element sizes (in this case, each element of the list is a vector) ``` a<-LETTERS[1:6] b<-LETTERS[6:10] c<-LETTERS[c(9:15)] l=list(a,b,c) > l [[1]] [1] "A" "B" "C" "D" "E" "F" [[2]] [1] "F" "G" "H" "I" "J" [[3]] [1] "I" "J" "K" "L" "M" "N" "O" ``` The shuffling should randomly select the letters of the list (without replacement) and put them in a random position of any vector within the list. I hope I have been clear! Thanks :-)

Original source