Format column data containing bin/interval information

When using cut() (or other functions that use it in some way) you get bins that can look like this: "(0,10]", "(10,15]", "(15,20]", "(20,40]". This interval notation expresses the lower and upper limits of each range. The square or round brackets define whether each of the endpoints are included in the range ([/] for inclusion, (/) for exclusion). Should bins of this sort be present in a table, the fmt_bins() function can be used to format that syntax to a form that presents better in a display table. It's possible to format the values of the intervals with the fmt argument, and, the separator can be modified with the sep argument.

Usage

fmt_bins(
  data,
  columns = everything(),
  rows = everything(),
  sep = "--",
  fmt = 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).

sep

Separator between values

scalar<character> // default: "--"

The separator text that indicates the values are ranged. The default value of "--" indicates that an en dash will be used for the range separator. Using "---" will be taken to mean that an em dash should be used. Should you want these special symbols to be taken literally, they can be supplied within base::I().

fmt

Formatting expressions

<single expression> // default: NULL (optional)

An optional formatting expression in formula form. If used, the RHS of ~ should contain a formatting call (e.g., ~ fmt_number(., decimals = 3, use_seps = FALSE).

Value

An object of class gt_tbl.

Compatibility of formatting function with data values

fmt_bins() is compatible with body cells that are of the "character" or "factor" 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.

Formatting expressions for `fmt`

We can supply a one-sided (RHS only) expression to fmt, and, several can be provided in a list. The expression uses a formatting function (e.g., fmt_number(), fmt_currency(), etc.) and it must contain an initial . that stands for the data object. If performing numeric formatting it might look something like this:

fmt = ~ fmt_number(., decimals = 1, use_seps = FALSE)

Examples

Use the countrypops dataset to create a gt table. Before even getting to the gt() call, we use cut() in conjunction with scales::breaks_log() to create some highly customized bins. Consequently each country's population in the 2021 year is assigned to a bin. These bins have a characteristic type of formatting that can be used as input to fmt_bins(), and using that formatting function allows us to customize the presentation of those ranges. For instance, here we are formatting the left and right values of the ranges with fmt_integer() (using formula syntax).

countrypops |>
  dplyr::filter(year == 2021) |>
  dplyr::select(country_code_2, population) |>
  dplyr::mutate(population_class = cut(
    population,
    breaks = scales::breaks_log(n = 20)(population)
    )
  ) |>
  dplyr::group_by(population_class) |>
  dplyr::summarize(
    count = dplyr::n(),
    countries = paste0(country_code_2, collapse = ",")
  ) |>
  dplyr::arrange(desc(population_class)) |>
  gt() |>
  fmt_flag(columns = countries) |>
  fmt_bins(
    columns = population_class,
    fmt = ~ fmt_integer(., suffixing = TRUE)
  ) |>
  cols_label(
    population_class = "Population Range",
    count = "",
    countries = "Countries"
  ) |>
  cols_width(
    population_class ~ px(150),
    count ~ px(50)
  ) |>
  tab_style(
    style = cell_text(style = "italic"),
    locations = cells_body(columns = count)
  )

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

Function ID

3-17

Function Introduced

v0.9.0 (Mar 31, 2023)