Dr. Manhattan - 3 months ago 13

R Question

Extending this former question, how can I shuffle (randomize) the following vector

`a1 = [1, 1, 2, 2, 2, 2, 3, 3, 4, 5, 5, 5]`

in order to get something like this:

`a2 = [5, 5, 3, 3, 3, 3, 1, 1, 2, 4, 4, 4]`

or even better like this:

`a3 = [4, 4, 4, 2, 3, 3, 3, 3, 1, 1, 5, 5]?`

such that each element could randomly change to another but with keeping the number of each element constant?

Answer

You can try something like this: create a factor from `a1`

with randomly shuffled levels and then convert it to integers:

```
as.integer(factor(a1, levels = sample(unique(a1), length(unique(a1)))))
# [1] 5 5 4 4 4 4 3 3 2 1 1 1
```