Ordered

As ordered

Usage

as_ordered(x)

# S3 method for default
as_ordered(x)

Arguments

x

A vector of values

Value

An ordered vector

Details

Simple implementation of ordered. If x is ordered it is simply returned. If x is a factor the ordered class is added. Otherwise, x is made into a factor with fact() and then the ordered class is added. Unlike just fact, ordered will replace the NA levels with NA_integer_ to work appropriately with other functions.

See also

fact()

Other factors: char2fact(), drop_levels(), fact2char(), fact_na(), fact()

Examples

x <- c("a", NA, "b")
x <- fact(x)
str(x) # NA is 3L
#>  Factor w/ 3 levels "a","b",NA: 1 3 2
#>  - attr(*, "uniques")= chr [1:3] "a" "b" NA
#>  - attr(*, "na")= int 3

y <- x
class(y) <- c("ordered", class(y))
max(y)
#> [1] <NA>
#> Levels: a < b
max(y, na.rm = TRUE) # returns NA -- bad
#> [1] b
#> Levels: a < b

# as_ordered() removes the NA level
x <- as_ordered(x)
str(x)
#>  Ord.factor w/ 2 levels "a"<"b": 1 NA 2
#>  - attr(*, "uniques")= chr [1:2] "a" "b"
#>  - attr(*, "na")= int 0
max(x, na.rm = TRUE) # returns b -- correct
#> [1] b
#> Levels: a < b