Skip to contents

With numeric values in a gt table, we can perform currency-based formatting with fmt_currency(). The function supports both automatic formatting with either a three-letter or a numeric currency code. We can also specify a custom currency that is formatted according to one or more output contexts with the currency() helper function. We have fine control over the conversion from numeric values to currency values, where we could take advantage of the following options:

  • the currency: providing a currency code or common currency name will procure the correct currency symbol and number of currency subunits; we could also use the currency() helper function to specify a custom currency

  • currency symbol placement: the currency symbol can be placed before or after the values

  • decimals/subunits: choice of the number of decimal places, and a choice of the decimal symbol, and an option on whether to include or exclude the currency subunits (the decimal portion)

  • negative values: choice of a negative sign or parentheses for values less than zero

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

  • scaling: we can choose to scale targeted values by a multiplier value

  • large-number suffixing: larger figures (thousands, millions, etc.) can be autoscaled and decorated with the appropriate suffixes

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

  • locale-based formatting: providing a locale ID will result in currency formatting specific to the chosen locale; it will also retrieve the locale's currency if none is explicitly given

We can call info_currencies() for a useful reference on all of the valid inputs to the currency argument.

Usage

fmt_currency(
  data,
  columns = everything(),
  rows = everything(),
  currency = NULL,
  use_subunits = TRUE,
  decimals = NULL,
  drop_trailing_dec_mark = TRUE,
  use_seps = TRUE,
  accounting = FALSE,
  scale_by = 1,
  suffixing = FALSE,
  pattern = "{x}",
  sep_mark = ",",
  dec_mark = ".",
  force_sign = FALSE,
  placement = "left",
  incl_space = FALSE,
  system = c("intl", "ind"),
  locale = NULL
)

Arguments

data

The gt table data object

obj:<gt_tbl> // required

This is the gt table object that is commonly created through use of the gt() function.

columns

Columns to target

<column-targeting expression> // default: everything()

Can either be a series of column names provided in c(), a vector of column indices, or a select helper function. Examples of select helper functions include starts_with(), ends_with(), contains(), matches(), one_of(), num_range(), and everything().

rows

Rows to target

<row-targeting expression> // default: everything()

In conjunction with columns, we can specify which of their rows should undergo formatting. The default everything() results in all rows in columns being formatted. Alternatively, we can supply a vector of row captions within c(), a vector of row indices, or a select helper function. Examples of select helper functions include starts_with(), ends_with(), contains(), matches(), one_of(), num_range(), and everything(). We can also use expressions to filter down to the rows we need (e.g., [colname_1] > 100 & [colname_2] < 50).

currency

Currency to use

scalar<character>|obj:<gt_currency> // default: NULL (optional)

The currency to use for the numeric value. This input can be supplied as a 3-letter currency code (e.g., "USD" for U.S. Dollars, "EUR" for the Euro currency). Use info_currencies() to get an information table with all of the valid currency codes and examples of each. Alternatively, we can provide a common currency name (e.g., "dollar", "pound", "yen", etc.) to simplify the process. Use info_currencies() with the type == "symbol" option to view an information table with all of the supported currency symbol names along with examples.

We can also use the currency() helper function to specify a custom currency, where the string could vary across output contexts. For example, using currency(html = "&fnof;", default = "f") would give us a suitable glyph for the Dutch guilder in an HTML output table, and it would simply be the letter "f" in all other output contexts). Please note that decimals will default to 2 when using the currency() helper function.

If nothing is provided here but a locale value has been set (either in this function call or as part of the initial gt() call), the currency will be obtained from that locale. Virtually all locales are linked to a territory that is a country (use info_locales() for details on all locales used in this package), so, the in-use (or de facto) currency will be obtained. As the default locale is "en", the "USD" currency will be used if neither a locale nor a currency value is given.

use_subunits

Show or hide currency subunits

scalar<logical> // default: TRUE

An option for whether the subunits portion of a currency value should be displayed. For example, with an input value of 273.81, the default formatting will produce "$273.81". Removing the subunits (with use_subunits = FALSE) will give us "$273".

decimals

Number of decimal places

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

The decimals values corresponds to the exact number of decimal places to use. This value is optional as a currency has an intrinsic number of decimal places (i.e., the subunits). A value such as 2.34 can, for example, be formatted with 0 decimal places and if the currency used is "USD" it would result in "$2". With 4 decimal places, the formatted value becomes "$2.3400".

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. For example, when use_subunits = FALSE or decimals = 0 a formatted value such as "$23" can be fashioned as "$23." by setting drop_trailing_dec_mark = FALSE.

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.

scale_by

Scale values by a fixed multiplier

scalar<numeric|integer> // default: 1

All numeric values will be multiplied by the scale_by value before undergoing formatting. Since the default value is 1, no values will be changed unless a different multiplier value is supplied. This value will be ignored if using any of the suffixing options (i.e., where suffixing is not set to FALSE).

suffixing

Specification for large-number suffixing

scalar<logical>|vector<character> // default: FALSE

The suffixing option allows us to scale and apply suffixes to larger numbers (e.g., 1924000 can be transformed to 1.92M). This option can accept a logical value, where FALSE (the default) will not perform this transformation and TRUE will apply thousands ("K"), millions ("M"), billions ("B"), and trillions ("T") suffixes after automatic value scaling.

We can alternatively provide a character vector that serves as a specification for which symbols are to used for each of the value ranges. These preferred symbols will replace the defaults (e.g., c("k", "Ml", "Bn", "Tr") replaces "K", "M", "B", and "T").

Including NA values in the vector will ensure that the particular range will either not be included in the transformation (e.g., c(NA, "M", "B", "T") won't modify numbers at all in the thousands range) or the range will inherit a previous suffix (e.g., with c("K", "M", NA, "T"), all numbers in the range of millions and billions will be in terms of millions).

Any use of suffixing (where it is not set expressly as FALSE) means that any value provided to scale_by will be ignored.

If using system = "ind" then the default suffix set provided by suffixing = TRUE will be the equivalent of c(NA, "L", "Cr"). This doesn't apply suffixes to the thousands range, but does express values in lakhs and crores.

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.

placement

Currency symbol placement

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

The placement of the currency symbol. This can be either be "left" (as in "$450") or "right" (which yields "450$").

incl_space

Include a space between the value and the currency symbol

scalar<logical> // default: FALSE

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

system

Numbering system for grouping separators

singl-kw:[intl|ind] // default: "intl"

The international numbering system (keyword: "intl") is widely used and its grouping separators (i.e., sep_mark) are always separated by three digits. The alternative system, the Indian numbering system (keyword: "ind"), uses grouping separators that correspond to thousand, lakh, crore, and higher quantities.

locale

Locale identifier

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

An optional locale identifier that can be used for formatting values according 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. A locale ID can be also set in the initial gt() function call (where it would be used automatically by any function with a locale argument) but a locale value provided here will override that global locale.

Value

An object of class gt_tbl.

Compatibility of formatting function with data values

fmt_currency() is compatible with body cells that are of the "numeric" or "integer" types. Any other types of body cells are ignored during formatting. This is to say that cells of incompatible data types may be targeted, but there will be no attempt to format them.

Targeting cells with columns and rows

Targeting of values is done through columns and additionally by rows (if nothing is provided for rows then entire columns are selected). The columns argument allows us to target a subset of cells contained in the resolved columns. We say resolved because aside from declaring column names in c() (with bare column names or names in quotes) we can use tidyselect-style expressions. This can be as basic as supplying a select helper like starts_with(), or, providing a more complex incantation like

where(~ is.numeric(.x) && max(.x, na.rm = TRUE) > 1E6)

which targets numeric columns that have a maximum value greater than 1,000,000 (excluding any NAs from consideration).

By default all columns and rows are selected (with the everything() defaults). Cell values that are incompatible with a given formatting function will be skipped over, like character values and numeric fmt_*() functions. So it's safe to select all columns with a particular formatting function (only those values that can be formatted will be formatted), but, you may not want that. One strategy is to format the bulk of cell values with one formatting function and then constrain the columns for later passes with other types of formatting (the last formatting done to a cell is what you get in the final output).

Once the columns are targeted, we may also target the rows within those columns. This can be done in a variety of ways. If a stub is present, then we potentially have row identifiers. Those can be used much like column names in the columns-targeting scenario. We can use simpler tidyselect-style expressions (the select helpers should work well here) and we can use quoted row identifiers in c(). It's also possible to use row indices (e.g., c(3, 5, 6)) though these index values must correspond to the row numbers of the input data (the indices won't necessarily match those of rearranged rows if row groups are present). One more type of expression is possible, an expression that takes column values (can involve any of the available columns in the table) and returns a logical vector. This is nice if you want to base formatting on values in the column or another column, or, you'd like to use a more complex predicate expression.

Compatibility of arguments with the from_column() helper function

from_column() can be used with certain arguments of fmt_currency() to obtain varying parameter values from a specified column within the table. This means that each row could be formatted a little bit differently. These arguments provide support for from_column():

  • currency

  • use_subunits

  • decimals

  • drop_trailing_dec_mark

  • use_seps

  • accounting

  • scale_by

  • suffixing

  • pattern

  • sep_mark

  • dec_mark

  • force_sign

  • placement

  • incl_space

  • system

  • locale

Please note that for all of the aforementioned arguments, a from_column() call needs to reference a column that has data of the correct type (this is different for each argument). Additional columns for parameter values can be generated with cols_add() (if not already present). Columns that contain parameter data can also be hidden from final display with cols_hide(). Finally, there is no limitation to how many arguments the from_column() helper is applied so long as the arguments belong to this closed set.

Adapting output to a specific locale

This formatting function can adapt outputs according to a provided locale value. Examples include "en" for English (United States) and "fr" for French (France). The use of a locale ID here means separator and decimal marks will be correct for the given locale. Should any values be provided in sep_mark or dec_mark, they will be overridden by the locale's preferred values. In addition to number formatting, providing a locale value and not providing a currency allows gt to obtain the currency code from the locale's territory.

Note that a locale value provided here will override any global locale setting performed in gt()'s own locale argument (it is settable there as a value received by all other functions that have a locale argument). As a useful reference on which locales are supported, we can call info_locales() to view an info table.

Examples

Let's make a simple gt table from the exibble dataset. We'll keep only the num and currency, columns, then, format those columns using fmt_currency() (with the "JPY" and "GBP" currencies).

exibble |>
  dplyr::select(num, currency) |>
  gt() |>
  fmt_currency(
    columns = num,
    currency = "JPY"
  ) |>
  fmt_currency(
    columns = currency,
    currency = "GBP"
  )

This image of a table was generated from the first code example in the `fmt_currency()` help file.

Let's take a single column from exibble (currency) and format it with a currency name (this differs from the 3-letter currency code). In this case, we'll use the "euro" currency and set the placement of the symbol to the right of any value. Additionally, the currency symbol will separated from the value with a single space character (using incl_space = TRUE).

exibble |>
  dplyr::select(currency) |>
  gt() |>
  fmt_currency(
    currency = "euro",
    placement = "right",
    incl_space = TRUE
  )

This image of a table was generated from the second code example in the `fmt_currency()` help file.

With the pizzaplace dataset, let's make a summary table that gets the number of "hawaiian" pizzas sold (and revenue generated) by month. In the gt table, we'll format only the revenue column. The currency value is automatically U.S. Dollars when don't supply either a currency code or a locale. We'll also create a grand summary with grand_summary_rows(). Within that summary row, the total revenue needs to be formatted with fmt_currency() and we can do that within the fmt argument.

pizzaplace |>
  dplyr::filter(name == "hawaiian") |>
  dplyr::mutate(month = lubridate::month(date, label = TRUE, abbr = TRUE)) |>
  dplyr::select(month, price) |>
  dplyr::group_by(month) |>
  dplyr::summarize(
    `number sold` = dplyr::n(),
    revenue = sum(price)
  ) |>
  gt(rowname_col = "month") |>
  tab_header(title = "Summary of Hawaiian Pizzas Sold by Month") |>
  fmt_currency(columns = revenue) |>
  grand_summary_rows(
    fns = list(label = "Totals:", id = "totals", fn = "sum"),
    fmt = ~ fmt_currency(., columns = revenue),
  ) |>
  opt_all_caps()

This image of a table was generated from the third code example in the `fmt_currency()` help file.

If supplying a locale value to fmt_currency(), we can opt use the locale's assumed currency and not have to supply a currency value (doing so would override the locale's default currency). With a column of locale values, we can format currency values on a row-by-row basis through the use of from_column(). Here, we'll reference the locale column in the argument of the same name.

dplyr::tibble(
  amount = rep(50.84, 5),
  currency = c("JPY", "USD", "GHS", "KRW", "CNY"),
  locale = c("ja", "en", "ee", "ko", "zh"),
) |>
  gt() |>
  fmt_currency(
    columns = amount,
    locale = from_column(column = "locale")
  ) |>
  cols_hide(columns = locale)

This image of a table was generated from the fourth code example in the `fmt_currency()` help file.

We can similarly use from_column() to reference a column that has currency code values. Here's an example of how to create a simple currency conversion table. The curr column contains the 3-letter currency codes, and that column is referenced via from_column() in the currency argument of fmt_currency().

dplyr::tibble(
  flag = c("EU", "GB", "CA", "AU", "JP", "IN"),
  curr = c("EUR", "GBP", "CAD", "AUD", "JPY", "INR"),
  conv = c(
    0.912952, 0.787687, 1.34411,
    1.53927, 144.751, 82.9551
  )
) |>
  gt() |>
  fmt_currency(
    columns = conv,
    currency = from_column(column = "curr")
  ) |>
  fmt_flag(columns = flag) |>
  cols_merge(columns = c(flag, curr)) |>
  cols_label(
    flag = "Currency",
    conv = "Amount"
  ) |>
  tab_header(
    title = "Conversion of 1 USD to Six Other Currencies",
    subtitle = md("Conversion rates obtained on **Aug 13, 2023**")
  )

This image of a table was generated from the fifth code example in the `fmt_currency()` help file.

Function ID

3-8

Function Introduced

v0.2.0.5 (March 31, 2020)