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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

The input vector

vector(numeric|integer) // required

This is the input vector that will undergo transformation to a character vector of the same length. Values within the vector will be formatted.

decimals

Number of decimal places

scalar<numeric|integer>(val>=0) // default: 2

This corresponds to the exact number of decimal places to use. A value such as 2.34 can, for example, be formatted with 0 decimal places and it would result in "2". With 4 decimal places, the formatted value becomes "2.3400".

drop_trailing_zeros

Drop any trailing zeros

scalar<logical> // default: FALSE

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

drop_trailing_dec_mark

Drop the trailing decimal mark

scalar<logical> // default: TRUE

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. if FALSE). By default trailing decimal marks are not shown.

scale_values

Multiply input values by 100

scalar<logical> // default: TRUE

Should the values be scaled through multiplication by 100? By default this scaling is performed since the expectation is that incoming values are usually proportional. Setting to FALSE signifies that the values are already scaled and require only the percent sign when formatted.

use_seps

Use digit group separators

scalar<logical> // default: TRUE

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

Use accounting style

scalar<logical> // default: FALSE

An option to use accounting style for values. Normally, negative values will be shown with a minus sign but using accounting style will instead put any negative values in parentheses.

pattern

Specification of the formatting pattern

scalar<character> // default: "{x}"

A formatting pattern that allows for decoration of the formatted value. The formatted value is represented by the {x} (which can be used multiple times, if needed) and all other characters will be interpreted as string literals.

sep_mark

Separator mark for digit grouping

scalar<character> // default: ","

The string to use as a separator between groups of digits. For example, using sep_mark = "," with a value of 1000 would result in a formatted value of "1,000". This argument is ignored if a locale is supplied (i.e., is not NULL).

dec_mark

Decimal mark

scalar<character> // default: "."

The string to be used as the decimal mark. For example, using dec_mark = "," with the value 0.152 would result in a formatted value of "0,152"). This argument is ignored if a locale is supplied (i.e., is not NULL).

force_sign

Forcing the display of a positive sign

scalar<logical> // default: FALSE

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

Include a space between the value and the % sign

scalar<logical> // default: FALSE

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

Percent sign placement

singl-kw:[right|left] // default: "right"

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

locale

Locale identifier

scalar<character> // default: NULL (optional)

An optional locale identifier that can be used for formatting values according to the locale's rules. Examples include "en" for English (United States) and "fr" for French (France). We can call info_locales() for a useful reference for all of the locales that are supported.

output

Output format

singl-kw:[auto|plain|html|latex|rtf|word] // default: "auto"

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

15-5

Function Introduced

v0.7.0 (Aug 25, 2022)

See also

The variant function intended for formatting gt table data: fmt_percent().

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