Compare two clustering with the Adjusted Rand Index

## Arguments

- x
A vector of integers, the clusters labels

- y
A vector of integers of the same length as x, the clusters labels

## Value

A number between 0 (random clustering) and 1 (identical clustering)

## Examples

```
ARI(x = c(1, 2, 1), y = c(2, 2, 1))
#> [1] -0.5
```