fct_shift {forcats}

Shift factor levels to left or right, wrapping around at end

Description

This is useful when the levels of an ordered factor are actually cyclical, with different conventions on the starting point.

Usage

fct_shift(f, n = 1L)

Arguments

f

A factor.

n

Positive values shift to the left; negative values shift to the right.

Examples

x <- factor(
  c("Mon", "Tue", "Wed"),
  levels = c("Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"),
  ordered = TRUE
)
x
fct_shift(x)
fct_shift(x, 2)
fct_shift(x, -1)