Return the name of the grouping factors from mixed effects models.

## Arguments

- x
A fitted mixed model.

- split_nested
Logical, if

`TRUE`

, terms from nested random effects will be returned as separated elements, not as single string with colon. See 'Examples'.- flatten
Logical, if

`TRUE`

, the values are returned as character vector, not as list. Duplicated values are removed.

## Value

A list of character vectors that represent the name(s) of the random effects (grouping factors). Depending on the model, the returned list has following elements:

`random`

, the "random effects" terms from the conditional part of model`zero_inflated_random`

, the "random effects" terms from the zero-inflation component of the model

## Examples

```
if (require("lme4")) {
data(sleepstudy)
sleepstudy$mygrp <- sample(1:5, size = 180, replace = TRUE)
sleepstudy$mysubgrp <- NA
for (i in 1:5) {
filter_group <- sleepstudy$mygrp == i
sleepstudy$mysubgrp[filter_group] <-
sample(1:30, size = sum(filter_group), replace = TRUE)
}
m <- lmer(
Reaction ~ Days + (1 | mygrp / mysubgrp) + (1 | Subject),
data = sleepstudy
)
find_random(m)
find_random(m, split_nested = TRUE)
}
#> boundary (singular) fit: see help('isSingular')
#> $random
#> [1] "mysubgrp" "mygrp" "Subject"
#>
```