Format numeric values

With numeric values in a gt table, we can perform number-based formatting so that the targeted values are rendered with a higher consideration for tabular presentation. Furthermore, there is finer control over numeric formatting with the following options:

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

Usage

fmt_number(
  data,
  columns = everything(),
  rows = everything(),
  decimals = 2,
  n_sigfig = NULL,
  drop_trailing_zeros = FALSE,
  drop_trailing_dec_mark = TRUE,
  use_seps = TRUE,
  accounting = FALSE,
  scale_by = 1,
  suffixing = FALSE,
  pattern = "{x}",
  sep_mark = ",",
  dec_mark = ".",
  force_sign = 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 (e.g. starts_with(), ends_with(), contains(), matches(), 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 (e.g. starts_with(), ends_with(), contains(), matches(), 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).

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".

n_sigfig

Number of significant figures

scalar<numeric|integer>(val>=1) // default: NULL (optional)

A option to format numbers to n significant figures. By default, this is NULL and thus number values will be formatted according to the number of decimal places set via decimals. If opting to format according to the rules of significant figures, n_sigfig must be a number greater than or equal to 1. Any values passed to the decimals and drop_trailing_zeros arguments will be ignored.

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.

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 be 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.

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 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. 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_number() 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.

Compatibility of arguments with the `from_column()` helper function

from_column() can be used with certain arguments of fmt_number() 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():

decimals
n_sigfig
drop_trailing_zeros
drop_trailing_dec_mark
use_seps
accounting
scale_by
suffixing
pattern
sep_mark
dec_mark
force_sign
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 valid 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.

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 use the exibble dataset to create a gt table. With fmt_number(), we'll format the num column to have three decimal places (with decimals = 3) and omit the use of digit separators (with use_seps = FALSE).

exibble |>
  gt() |>
  fmt_number(
    columns = num,
    decimals = 3,
    use_seps = FALSE
  )

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

Use a modified version of the countrypops dataset to create a gt table with row labels. Format all columns to use large-number suffixing (e.g., where "10,000,000" becomes "10M") with the suffixing = TRUE option.

countrypops |>
  dplyr::select(country_code_3, year, population) |>
  dplyr::filter(country_code_3 %in% c("CHN", "IND", "USA", "PAK", "IDN")) |>
  dplyr::filter(year > 1975 & year %% 5 == 0) |>
  tidyr::spread(year, population) |>
  dplyr::arrange(desc(`2015`)) |>
  gt(rowname_col = "country_code_3") |>
  fmt_number(suffixing = TRUE)

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

In a variation of the previous table, we can combine large-number suffixing with a declaration of the number of significant digits to use. With things like population figures, n_sigfig = 3 is a very good option.

countrypops |>
  dplyr::select(country_code_3, year, population) |>
  dplyr::filter(country_code_3 %in% c("CHN", "IND", "USA", "PAK", "IDN")) |>
  dplyr::filter(year > 1975 & year %% 5 == 0) |>
  tidyr::spread(year, population) |>
  dplyr::arrange(desc(`2015`)) |>
  gt(rowname_col = "country_code_3") |>
  fmt_number(suffixing = TRUE, n_sigfig = 3)

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

There can be cases where you want to show numbers to a large number of decimal places but also drop the unnecessary trailing zeros for low-precision values. Let's take a portion of the towny dataset and format the latitude and longitude columns with fmt_number(). We'll have up to 5 digits displayed as decimal values, but we'll also unconditionally drop any runs of trailing zeros in the decimal part with drop_trailing_zeros = TRUE.

towny |>
  dplyr::select(name, latitude, longitude) |>
  dplyr::slice_head(n = 10) |>
  gt() |>
  fmt_number(decimals = 5, drop_trailing_zeros = TRUE) |>
  cols_merge(columns = -name, pattern = "{1}, {2}") |>
  cols_label(
    name ~ "Municipality",
    latitude = "Location"
  )

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

Another strategy for dealing with precision of decimals is to have a separate column of values that specify how many decimal digits to retain. Such a column can be added via cols_add() or it can be part of the input table for gt(). With that column available, it can be referenced in the decimals argument with from_column(). This approach yields a display of coordinate values that reflects the measurement precision of each value.

towny |>
  dplyr::select(name, latitude, longitude) |>
  dplyr::slice_head(n = 10) |>
  gt() |>
  cols_add(dec_digits = c(1, 2, 2, 5, 5, 2, 3, 2, 3, 3)) |>
  fmt_number(decimals = from_column(column = "dec_digits")) |>
  cols_merge(columns = -name, pattern = "{1}, {2}") |>
  cols_label(
    name ~ "Municipality",
    latitude = "Location"
  )

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

Function ID

3-1

Function Introduced

v0.2.0.5 (March 31, 2020)

Usage

Arguments

Value

Compatibility of formatting function with data values

Compatibility of arguments with the from_column() helper function

Adapting output to a specific locale

Examples

Function ID

Function Introduced

See also

Compatibility of arguments with the `from_column()` helper function

Adapting output to a specific `locale`