Label chopped intervals by their left or right endpoints

This is useful when the left endpoint unambiguously indicates the interval. In other cases it may give errors due to duplicate labels.

Usage

lbl_endpoints(
  left = TRUE,
  fmt = NULL,
  single = NULL,
  first = NULL,
  last = NULL,
  raw = FALSE
)

lbl_endpoint(fmt = NULL, raw = FALSE, left = TRUE)

Arguments

left

Flag. Use left endpoint or right endpoint?

fmt

String, list or function. A format for break endpoints.

single

Glue string: label for singleton intervals. See lbl_glue() for details.

first

Glue string: override label for the first category. Write e.g. first = "<{r}" to create a label like "<18". See lbl_glue() for details.

last

String: override label for the last category. Write e.g. last = ">{l}" to create a label like ">65". See lbl_glue() for details.

raw

. Use the raw argument to chop() instead.

Value

A function that creates a vector of labels.

Details

lbl_endpoint() is . Do not use it.

Formatting endpoints

If fmt is not NULL then it is used to format the endpoints.

• If fmt is a string, then numeric endpoints will be formatted by sprintf(fmt, breaks); other endpoints, e.g. Date objects, will be formatted by format(breaks, fmt).

• If fmt is a list, then it will be used as arguments to format.

• If fmt is a function, it should take a vector of numbers (or other objects that can be used as breaks) and return a character vector. It may be helpful to use functions from the {scales} package, e.g. scales::label_comma().

See also

Other labelling functions: lbl_dash(), lbl_discrete(), lbl_glue(), lbl_intervals(), lbl_manual(), lbl_midpoints(), lbl_seq()

Examples

chop(1:10, c(2, 5, 8), lbl_endpoints(left = TRUE))
#>  [1] 1 2 2 2 5 5 5 8 8 8
#> Levels: 1 2 5 8
chop(1:10, c(2, 5, 8), lbl_endpoints(left = FALSE))
#>  [1] 2  5  5  5  8  8  8  10 10 10
#> Levels: 2 5 8 10
if (requireNamespace("lubridate")) {
  tab_width(
          as.Date("2000-01-01") + 0:365,
         months(1),
         labels = lbl_endpoints(fmt = "%b")
       )
}
#> Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 
#>  31  29  31  30  31  30  31  31  30  31  30  31 

if (FALSE) {
  # This gives breaks `[1, 2) [2, 3) {3}` which lead to
  # duplicate labels `"2", "3", "3"`:
  chop(1:3, 1:3, lbl_endpoints(left = FALSE))
}