The fmt_auto()
function will automatically apply formatting of various
types in a way that best suits the data table provided. The function will
attempt to format numbers such that they are condensed to an optimal width,
either with scientific notation or large-number suffixing. Currency values
are detected by currency codes embedded in the column name and formatted in
the correct way. Although the functionality here is comprehensive it's still
possible to reduce the scope of automatic formatting with the scope
argument and also by choosing a subset of columns and rows to which the
formatting will be applied.
Usage
fmt_auto(
data,
columns = everything(),
rows = everything(),
scope = c("numbers", "currency"),
lg_num_pref = c("sci", "suf"),
locale = NULL
)
Arguments
- data
The gt table data object
obj:<gt_tbl>
--- requiredThis 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 includestarts_with()
,ends_with()
,contains()
,matches()
,one_of()
,num_range()
, andeverything()
.- rows
Rows to target
<row-targeting expression>
--- default:everything()
In conjunction with
columns
, we can specify which of their rows should undergo formatting. The defaulteverything()
results in all rows incolumns
being formatted. Alternatively, we can supply a vector of row captions withinc()
, a vector of row indices, or a select helper function. Examples of select helper functions includestarts_with()
,ends_with()
,contains()
,matches()
,one_of()
,num_range()
, andeverything()
. We can also use expressions to filter down to the rows we need (e.g.,[colname_1] > 100 & [colname_2] < 50
).- scope
Scope of automatic formatting
mult-kw:[numbers|currency]
--- default:c("numbers", "currency")
By default, the function will format both
"numbers"
-type values and"currency"
-type values though the scope can be reduced to a single type of value to format.- lg_num_pref
Large-number preference
singl-kw:[sci|suf]
--- default:"sci"
When large numbers are present, there can be a fixed preference toward how they are formatted. Choices are scientific notation for very small and very large values (
"sci"
), or, the use of suffixed numbers ("suf"
, for large values only).- 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 use theinfo_locales()
function as a useful reference for all of the locales that are supported. A locale ID can be also set in the initialgt()
function call (where it would be used automatically by any function with alocale
argument) but alocale
value provided here will override that global locale.
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 NA
s 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.
Examples
Use the exibble
dataset to create a gt table. Format all of the
columns automatically with the fmt_auto()
function.
Let's now use the countrypops
dataset to create another gt table.
We'll again use fmt_auto()
to automatically format all columns but this
time the choice will be made to opt for large-number suffixing instead of
scientific notation. This is done by using the lg_num_pref = "suf"
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(`2020`)) |>
gt(rowname_col = "country_code_3") |>
fmt_auto(lg_num_pref = "suf")
See also
Other data formatting functions:
data_color()
,
fmt_bins()
,
fmt_bytes()
,
fmt_currency()
,
fmt_datetime()
,
fmt_date()
,
fmt_duration()
,
fmt_engineering()
,
fmt_flag()
,
fmt_fraction()
,
fmt_image()
,
fmt_index()
,
fmt_integer()
,
fmt_markdown()
,
fmt_number()
,
fmt_partsper()
,
fmt_passthrough()
,
fmt_percent()
,
fmt_roman()
,
fmt_scientific()
,
fmt_spelled_num()
,
fmt_time()
,
fmt_url()
,
fmt()
,
sub_large_vals()
,
sub_missing()
,
sub_small_vals()
,
sub_values()
,
sub_zero()