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Formatter for p-values, using "<" and ">" for p-values close to 0 and 1.


  accuracy = 0.001,
  decimal.mark = ".",
  prefix = NULL,
  add_p = FALSE



A number to round to. Use (e.g.) 0.01 to show 2 decimal places of precision. If NULL, the default, uses a heuristic that should ensure breaks have the minimum number of digits needed to show the difference between adjacent values.

Applied to rescaled data.


The character to be used to indicate the numeric decimal point.


A character vector of length 3 giving the prefixes to put in front of numbers. The default values are c("<", "", ">") if add_p is TRUE and c("p<", "p=", "p>") if FALSE.


Add "p=" before the value?


All label_() functions return a "labelling" function, i.e. a function that takes a vector x and returns a character vector of length(x) giving a label for each input value.

Labelling functions are designed to be used with the labels argument of ggplot2 scales. The examples demonstrate their use with x scales, but they work similarly for all scales, including those that generate legends rather than axes.

See also


demo_continuous(c(0, 1))
#> scale_x_continuous()

demo_continuous(c(0, 1), labels = label_pvalue())
#> scale_x_continuous(labels = label_pvalue())

demo_continuous(c(0, 1), labels = label_pvalue(accuracy = 0.1))
#> scale_x_continuous(labels = label_pvalue(accuracy = 0.1))

demo_continuous(c(0, 1), labels = label_pvalue(add_p = TRUE))
#> scale_x_continuous(labels = label_pvalue(add_p = TRUE))

# Or provide your own prefixes
prefix <- c("p < ", "p = ", "p > ")
demo_continuous(c(0, 1), labels = label_pvalue(prefix = prefix))
#> scale_x_continuous(labels = label_pvalue(prefix = prefix))