Skip to contents

Format a vector as percentage values

Source: R/format_vec.R
vec_fmt_percent.Rd

With numeric values in vector, we can perform percentage-based formatting. It is assumed that numeric values in the input vector are proportional values and, in this case, the values will be automatically multiplied by 100 before decorating with a percent sign (the other case is accommodated though setting the scale_values to FALSE). For more control over percentage formatting, we can use the following options:

  • percent sign placement: the percent sign can be placed after or before the values and a space can be inserted between the symbol and the value.

  • decimals: choice of the number of decimal places, option to drop trailing zeros, and a choice of the decimal symbol

  • digit grouping separators: options to enable/disable digit separators and provide a choice of separator symbol

  • pattern: option to use a text pattern for decoration of the formatted values

  • locale-based formatting: providing a locale ID will result in number formatting specific to the chosen locale

Usage

vec_fmt_percent(
  x,
  decimals = 2,
  drop_trailing_zeros = FALSE,
  drop_trailing_dec_mark = TRUE,
  scale_values = TRUE,
  use_seps = TRUE,
  accounting = FALSE,
  pattern = "{x}",
  sep_mark = ",",
  dec_mark = ".",
  force_sign = FALSE,
  incl_space = FALSE,
  placement = "right",
  locale = NULL,
  output = c("auto", "plain", "html", "latex", "rtf", "word")
)

Arguments

x

A numeric vector.

decimals

An option to specify the exact number of decimal places to use. The default number of decimal places is 2.

drop_trailing_zeros

A logical value that allows for removal of trailing zeros (those redundant zeros after the decimal mark).

drop_trailing_dec_mark

A logical value that determines whether decimal marks should always appear even if there are no decimal digits to display after formatting (e.g, 23 becomes 23.). The default for this is TRUE, which means that trailing decimal marks are not shown.

scale_values

Should the values be scaled through multiplication by 100? By default this is TRUE since the expectation is that normally values are proportions. Setting to FALSE signifies that the values are already scaled and require only the percent sign when formatted.

use_seps

An option to use digit group separators. The type of digit group separator is set by sep_mark and overridden if a locale ID is provided to locale. This setting is TRUE by default.

accounting

An option to use accounting style for values. With FALSE (the default), negative values will be shown with a minus sign. Using accounting = TRUE will put negative values in parentheses.

pattern

A formatting pattern that allows for decoration of the formatted value. The value itself is represented by {x} and all other characters are taken to be string literals.

sep_mark

The mark to use as a separator between groups of digits (e.g., using sep_mark = "," with 1000 would result in a formatted value of 1,000).

dec_mark

The character to use as a decimal mark (e.g., using dec_mark = "," with 0.152 would result in a formatted value of 0,152).

force_sign

Should the positive sign be shown for positive values (effectively showing a sign for all values except zero)? If so, use TRUE for this option. The default is FALSE, where only negative numbers will display a minus sign. This option is disregarded when using accounting notation with accounting = TRUE.

incl_space

An option for whether to include a space between the value and the percent sign. The default is to not introduce a space character.

placement

The placement of the percent sign. This can be either be right (the default) or left.

locale

An optional locale ID that can be used for formatting the value according the locale's rules. Examples include "en" for English (United States) and "fr" for French (France). The use of a valid locale ID will override any values provided in sep_mark and dec_mark. We can use the info_locales() function as a useful reference for all of the locales that are supported.

output

The output style of the resulting character vector. This can either be "auto" (the default), "plain", "html", "latex", "rtf", or "word". In knitr rendering (i.e., Quarto or R Markdown), the "auto" option will choose the correct output value

Value

A character vector.

Examples

Let's create a numeric vector for the next few examples:

num_vals <- c(0.0052, 0.08, 0, -0.535, NA)

Using vec_fmt_percent() with the default options will create a character vector where the resultant percentage values have two decimal places and NA values will render as "NA". The rendering context will be autodetected unless specified in the output argument (here, it is of the "plain" output type).

vec_fmt_percent(num_vals)

#> [1] "0.52%" "8.00%" "0.00%" "-53.50%" "NA"

We can change the decimal mark to a comma, and we have to be sure to change the digit separator mark from the default comma to something else (a period works here):

vec_fmt_percent(num_vals, sep_mark = ".", dec_mark = ",")

#> [1] "0,52%" "8,00%" "0,00%" "-53,50%" "NA"

If we are formatting for a different locale, we could supply the locale ID and let gt handle these locale-specific formatting options:

vec_fmt_percent(num_vals, locale = "pt")

#> [1] "0,52%" "8,00%" "0,00%" "-53,50%" "NA"

There are many options for formatting values. Perhaps you need to have explicit positive and negative signs? Use force_sign = TRUE for that.

vec_fmt_percent(num_vals, force_sign = TRUE)

#> [1] "+0.52%" "+8.00%" "0.00%" "-53.50%" "NA"

Those trailing zeros past the decimal mark can be stripped out by using the drop_trailing_zeros option.

vec_fmt_percent(num_vals, drop_trailing_zeros = TRUE)

#> [1] "0.52%" "8%" "0%" "-53.5%" "NA"

As a last example, one can wrap the values in a pattern with the pattern argument. Note here that NA values won't have the pattern applied.

vec_fmt_percent(num_vals, pattern = "{x}wt")

#> [1] "0.52%wt" "8.00%wt" "0.00%wt" "-53.50%wt" "NA"

Function ID

14-5

See also

Other vector formatting functions: vec_fmt_bytes(), vec_fmt_currency(), vec_fmt_datetime(), vec_fmt_date(), vec_fmt_duration(), vec_fmt_engineering(), vec_fmt_fraction(), vec_fmt_integer(), vec_fmt_markdown(), vec_fmt_number(), vec_fmt_partsper(), vec_fmt_roman(), vec_fmt_scientific(), vec_fmt_time()