ref_level: Return the reference or specific level of a factor

In gratia: Graceful 'ggplot'-Based Graphics and Other Functions for GAMs Fitted Using 'mgcv'

Return the reference or specific level of a factor

Description

Extracts the reference or a specific level the supplied factor, returning it as a factor with the same levels as the one supplied.

Usage

ref_level(fct)

level(fct, level)

Arguments

fct	factor; the factor from which the reference or specific level will be extracted.
level	character; the specific level to extract in the case of level().

Value

A length 1 factor with the same levels as the supplied factor fct.

Examples

f <- factor(sample(letters[1:5], 100, replace = TRUE))

# the reference level
ref_level(f)

# a specific level
level(f, level = "b")

# note that the levels will always match the input factor
identical(levels(f), levels(ref_level(f)))
identical(levels(f), levels(level(f, "c")))

gratia documentation built on Feb. 16, 2023, 10:40 p.m.