I have a list of 9 factor variables: item <- c("a","b","c","d","e","f","g","h","i"). I would like to randomly allocate each of the 9 factor variables to 3 groups.
I tried this script but it might be a lot of work:
gp1 <- sample(item,3,replace=F)
> gp1
[1] "b" "h" "g"
I also tried the cut function but the variables have to be numeric:
gp <- cut(item, breaks = 3)
Error in cut.default(item, breaks = 3) : 'x' must be numeric
The expected output should look like this but with variables randomly allocated to each group:
grp1 grp1 grp3
d b i
c e h
a g f
Thank you for your help!
Just sample the items and put it in a matrix (which can also be converted to a data.frame if you so desire):
matrix(sample(item), ncol = 3)
## [,1] [,2] [,3]
## [1,] "b" "d" "a"
## [2,] "f" "i" "e"
## [3,] "h" "g" "c"
If the items won't split to equal lengths, you might consider split, where the splitting variable is based on the shuffling of how many groups you want.
For instance:
item <- item[-c(1, 2)]
split(item, sample(rep(1:3, length.out = length(item))))
## $`1`
## [1] "c" "e" "i"
##
## $`2`
## [1] "f" "g"
##
## $`3`
## [1] "d" "h"
##