percent: Percentages

In phsmethods: Standard Methods for Use in Public Health Scotland

Percentages

Description

percent is a lightweight S3 class allowing for pretty printing of proportions as percentages.
It aims to remove the need for creating character vectors of percentages.

Usage

as_percent(x, digits = 2)

NA_percent_

Arguments

x	⁠[numeric]⁠ vector of proportions.
digits	⁠[numeric(1)]⁠ - The number of digits that will be used for formatting. This is by default 2 and is applied whenever format(), as.character() and print() are called. This can also be controlled directly via format().

Details

Rounding

The rounding for percent vectors differs to that of base R rounding, namely in that halves are rounded up instead of rounded to even. This means that round(x) will round the percent vector x using halves-up rounding (like in the janitor package).

Formatting

By default all percentages are formatted to 2 decimal places which can be overwritten using format() or using round() if your required digits are less than 2. It's worth noting that the digits argument in format.percent uses decimal rounding instead of the usual significant digit rounding that format.default() uses.

Value

An object of class percent.

Examples

# Convert proportions to percentages
as_percent(seq(0, 1, 0.1))

# You can use round() as usual
p <- as_percent(15.56 / 100)
round(p)
round(p, digits = 1)

p2 <- as_percent(0.0005)
signif(p2, 2)
floor(p2)
ceiling(p2)

# We can do basic math operations as usual

# Order of operations doesn't matter
10 * as_percent(c(0, 0.5, 2))
as_percent(c(0, 0.5, 2)) * 10

as_percent(0.1) + as_percent(0.2)

# Formatting options
format(as_percent(2.674 / 100), digits = 2, symbol = " (%)")
# Prints nicely in data frames (and tibbles)
library(dplyr)
starwars %>%
  count(eye_color) %>%
  mutate(perc = as_percent(n / sum(n))) %>%
  arrange(desc(perc)) %>% # We can do numeric sorting with percent vectors
  mutate(perc_rounded = round(perc))

phsmethods documentation built on July 31, 2026, 5:06 p.m.