With numeric values in a gt table, we can perform mixed-fraction-based formatting. There are several options for setting the accuracy of the fractions. Furthermore, there is an option for choosing a layout (i.e., typesetting style) for the mixed-fraction output.
The following options are available for controlling this type of formatting:
accuracy: how to express the fractional part of the mixed fractions; there are three keyword options for this and an allowance for arbitrary denominator settings
simplification: an option to simplify fractions whenever possible
layout: We can choose to output values with diagonal or inline fractions
digit grouping separators: options to enable/disable digit separators and provide a choice of separator symbol for the whole number portion
pattern: option to use a text pattern for decoration of the formatted mixed fractions
locale-based formatting: providing a locale ID will result in number formatting specific to the chosen locale
Usage
fmt_fraction(
data,
columns = everything(),
rows = everything(),
accuracy = NULL,
simplify = TRUE,
layout = c("inline", "diagonal"),
use_seps = TRUE,
pattern = "{x}",
sep_mark = ",",
system = c("intl", "ind"),
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
).- accuracy
Accuracy of fractions
singl-kw:[low|med|high]|scalar<numeric|integer>(val>=1)
// default:"low"
The type of fractions to generate. This can either be one of the keywords
"low"
,"med"
, or"high"
(to generate fractions with denominators of up to 1, 2, or 3 digits, respectively) or an integer value greater than zero to obtain fractions with a fixed denominator (2
yields halves,3
is for thirds,4
is quarters, etc.). For the latter option, usingsimplify = TRUE
will simplify fractions where possible (e.g.,2/4
will be simplified as1/2
). By default, the"low"
option is used.- simplify
Simplify the fraction
scalar<logical>
// default:TRUE
If choosing to provide a numeric value for
accuracy
, the option to simplify the fraction (where possible) can be taken withTRUE
(the default). WithFALSE
, denominators in fractions will be fixed to the value provided inaccuracy
.- layout
Layout of fractions in HTML output
singl-kw:[inline|diagonal]
// default:"inline"
For HTML output, the
"inline"
layout is the default. This layout places the numerals of the fraction on the baseline and uses a standard slash character. The"diagonal"
layout will generate fractions that are typeset with raised/lowered numerals and a virgule.- 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 tolocale
. This setting isTRUE
by default.- 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 of1000
would result in a formatted value of"1,000"
. This argument is ignored if alocale
is supplied (i.e., is notNULL
).- 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 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.
Compatibility of formatting function with data values
The fmt_fraction()
formatting function 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 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.
Compatibility of arguments with the from_column()
helper function
The from_column()
helper function can be used with certain arguments of
fmt_fraction()
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()
:
accuracy
simplify
layout
use_seps
pattern
sep_mark
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 the cols_add()
function (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 value be
provided in sep_mark
, it 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 use the
info_locales()
function to view an info table.
Examples
Using a summarized version of the pizzaplace
dataset, let's create a
gt table. With the fmt_fraction()
function we can format the f_sold
and f_income
columns to display fractions. As for how the fractions are
represented, we are electing to use accuracy = 10
. This gives all fractions
as tenths. We won't simplify the fractions (by using simplify = FALSE
) and
this means that a fraction like 5/10
won't become 1/2
. With layout = "diagonal"
, we get a diagonal display of all fractions.
pizzaplace |>
dplyr::group_by(type, size) |>
dplyr::summarize(
sold = dplyr::n(),
income = sum(price),
.groups = "drop_last"
) |>
dplyr::group_by(type) |>
dplyr::mutate(
f_sold = sold / sum(sold),
f_income = income / sum(income),
) |>
dplyr::arrange(type, dplyr::desc(income)) |>
gt(rowname_col = "size") |>
tab_header(
title = "Pizzas Sold in 2015",
subtitle = "Fraction of Sell Count and Revenue by Size per Type"
) |>
fmt_integer(columns = sold) |>
fmt_currency(columns = income) |>
fmt_fraction(
columns = starts_with("f_"),
accuracy = 10,
simplify = FALSE,
layout = "diagonal"
) |>
sub_missing(missing_text = "") |>
tab_spanner(
label = "Sold",
columns = contains("sold")
) |>
tab_spanner(
label = "Revenue",
columns = contains("income")
) |>
text_transform(
locations = cells_body(),
fn = function(x) {
dplyr::case_when(
x == 0 ~ "<em>nil</em>",
x != 0 ~ x
)
}
) |>
cols_label(
sold = "Amount",
income = "Amount",
f_sold = md("_f_"),
f_income = md("_f_")
) |>
cols_align(align = "center", columns = starts_with("f")) |>
tab_options(
table.width = px(400),
row_group.as_column = TRUE
)
See also
The vector-formatting version of this function:
vec_fmt_fraction()
.
Other data formatting functions:
data_color()
,
fmt_auto()
,
fmt_bins()
,
fmt_bytes()
,
fmt_currency()
,
fmt_datetime()
,
fmt_date()
,
fmt_duration()
,
fmt_engineering()
,
fmt_flag()
,
fmt_icon()
,
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_units()
,
fmt_url()
,
fmt()
,
sub_large_vals()
,
sub_missing()
,
sub_small_vals()
,
sub_values()
,
sub_zero()