Compared to base R, when `x`

is a character, this function creates
levels in the order in which they appear, which will be the same on every
platform. (Base R sorts in the current locale which can vary from place
to place.) When `x`

is numeric, the ordering is based on the numeric
value and consistent with base R.

## Usage

```
as_factor(x, ...)
# S3 method for factor
as_factor(x, ...)
# S3 method for character
as_factor(x, ...)
# S3 method for numeric
as_factor(x, ...)
# S3 method for logical
as_factor(x, ...)
```

## Examples

```
# Character object
x <- c("a", "z", "g")
as_factor(x)
#> [1] a z g
#> Levels: a z g
as.factor(x)
#> [1] a z g
#> Levels: a g z
# Character object containing numbers
y <- c("1.1", "11", "2.2", "22")
as_factor(y)
#> [1] 1.1 11 2.2 22
#> Levels: 1.1 11 2.2 22
as.factor(y)
#> [1] 1.1 11 2.2 22
#> Levels: 1.1 11 2.2 22
# Numeric object
z <- as.numeric(y)
as_factor(z)
#> [1] 1.1 11 2.2 22
#> Levels: 1.1 2.2 11 22
as.factor(z)
#> [1] 1.1 11 2.2 22
#> Levels: 1.1 2.2 11 22
```