percent

A lightweight percent class that allows easy formatting of percentages.

Installation

You can install the development version of percent from GitHub with:

# install.packages("devtools")
devtools::install_github("NicChr/percent")

Motivation

In day-to-day analyses I always find myself in this general workflow:

• Create one vector of proportions
• Create another vector of formatted percentages
• Make sure to use the proportions for math operations and the percentages for pretty outputs

percent aims to reduce this workflow by combining the two vectors into one, reducing the work needed to manage independent vectors.

Examples

We can create percentages using percent()

library(percent)
percent(0:10)
#>  [1] "0%"  "1%"  "2%"  "3%"  "4%"  "5%"  "6%"  "7%"  "8%"  "9%"  "10%"

This is simply a wrapper that converts 10 to the proportion 0.1 and prints it nicely as 10%.

Math operations

In a nutshell this means we can use it for further mathematical operations.

100 * percent(50)
#> [1] 50

When we do math operations on 2 percent vectors, a percent vector is returned

percent(1:10) + percent(20)
#>  [1] "21%" "22%" "23%" "24%" "25%" "26%" "27%" "28%" "29%" "30%"

Proportions

When you have proportions, use as_percent

prop <- seq(0, 1, 0.1)

as_percent(prop)
#>  [1] "0%"   "10%"  "20%"  "30%"  "40%"  "50%"  "60%"  "70%"  "80%"  "90%" 
#> [11] "100%"

Formatting

To round it to a specified number of decimal places, we can use round()

p <- percent(15.56)
round(p)
#> [1] "16%"
round(p, digits = 1)
#> [1] "15.6%"

The other rounding operators will also work as expected

p2 <- as_percent(0.0005)
signif(p2, 2)
#> [1] "0.05%"
floor(p2)
#> [1] "0%"
ceiling(p2)
#> [1] "1%"

We can also format a percent using the format() function

format(percent(2.674), digits = 2, symbol = "(%)")
#> [1] "2.67(%)"

A key note to point out is the digits in format.percent() are decimal places and not significant digits.

format(round(percent(2.674), 2), symbol = "(%)")
#> [1] "2.67(%)"