With numeric values in a vector, we can format the values so that they
are rendered as per mille, ppm, ppb, etc., quantities. The following
list of keywords (with associated naming and scaling factors) is available to
use within vec_fmt_partsper():
"per-mille": Per mille, (1 part in 1,000)
"per-myriad": Per myriad, (1 part in 10,000)
"pcm": Per cent mille (1 part in 100,000)
"ppm": Parts per million, (1 part in 1,000,000)
"ppb": Parts per billion, (1 part in 1,000,000,000)
"ppt": Parts per trillion, (1 part in 1,000,000,000,000)
"ppq": Parts per quadrillion, (1 part in 1,000,000,000,000,000)
The function provides a lot of formatting control and we can use the following options:
custom symbol/units: we can override the automatic symbol or units display with our own choice as the situation warrants
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
value scaling toggle: choose to disable automatic value scaling in the situation that values are already scaled coming in (and just require the appropriate symbol or unit display)
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
vec_fmt_partsper(
x,
to_units = c("per-mille", "per-myriad", "pcm", "ppm", "ppb", "ppt", "ppq"),
symbol = "auto",
decimals = 2,
drop_trailing_zeros = FALSE,
drop_trailing_dec_mark = TRUE,
scale_values = TRUE,
use_seps = TRUE,
pattern = "{x}",
sep_mark = ",",
dec_mark = ".",
force_sign = FALSE,
incl_space = "auto",
locale = NULL,
output = c("auto", "plain", "html", "latex", "rtf", "word")
)A character vector.
A numeric vector.
A keyword that signifies the desired output quantity. This
can be any from the following set: "per-mille", "per-myriad", "pcm",
"ppm", "ppb", "ppt", or "ppq".
The symbol/units to use for the quantity. By default, this is
set to "auto" and gt will choose the appropriate symbol based on the
to_units keyword and the output context. However, this can be changed by
supplying a string (e.g, using symbol = "ppbV" when to_units = "ppb").
An option to specify the exact number of decimal places to
use. The default number of decimal places is 2.
A logical value that allows for removal of trailing zeros (those redundant zeros after the decimal mark).
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.). The default for this is TRUE,
which means that trailing decimal marks are not shown.
Should the values be scaled through multiplication
according to the keyword set in to_units? By default this is TRUE since
the expectation is that normally values are proportions. Setting to FALSE
signifies that the values are already scaled and require only the
appropriate symbol/units when formatted.
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.
A formatting pattern that allows for decoration of the
formatted value. The value itself is represented by {x} and all other
characters are taken to be string literals.
The mark to use as a separator between groups of digits
(e.g., using sep_mark = "," with 1000 would result in a formatted value
of 1,000).
The character to use as a decimal mark (e.g., using
dec_mark = "," with 0.152 would result in a formatted value of
0,152).
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.
An option for whether to include a space between the value
and the symbol/units. The default is "auto" which provides spacing
dependent on the mark itself. This can be directly controlled by using
either TRUE or FALSE.
An optional locale ID that can be used for formatting the value
according the locale's rules. Examples include "en_US" for English
(United States) and "fr_FR" for French (France). The use of a valid
locale ID will override any values provided in sep_mark and dec_mark.
We can use the info_locales() function as a useful reference for all of
the locales that are supported.
The output style of the resulting character vector. This can
either be "auto" (the default), "plain", "html", "latex", "rtf",
or "word". In knitr rendering (i.e., Quarto or R Markdown), the
"auto" option will choose the correct output value
Let's create a numeric vector for the next few examples:
num_vals <- c(10^(-3:-5), NA)
Using vec_fmt_partsper() with the default options will create a character
vector where the resultant per millle values have two decimal places and NA
values will render as "NA". The rendering context will be autodetected
unless specified in the output argument (here, it is of the "plain"
output type).
vec_fmt_partsper(num_vals)
#> [1] "1.00‰" "0.10‰" "0.01‰" "NA"
We can change the output units to a different measure. If ppm units are
desired then to_units = "ppm" can be used.
vec_fmt_partsper(num_vals, to_units = "ppm")
#> [1] "1,000.00 ppm" "100.00 ppm" "10.00 ppm" "NA"
We can change the decimal mark to a comma, and we have to be sure to change the digit separator mark from the default comma to something else (a period works here):
vec_fmt_partsper(num_vals, to_units = "ppm", sep_mark = ".", dec_mark = ",")
#> [1] "1.000,00 ppm" "100,00 ppm" "10,00 ppm" "NA"
If we are formatting for a different locale, we could supply the locale ID and let gt handle these locale-specific formatting options:
vec_fmt_partsper(num_vals, to_units = "ppm", locale = "es")
#> [1] "1.000,00 ppm" "100,00 ppm" "10,00 ppm" "NA"
As a last example, one can wrap the values in a pattern with the pattern
argument. Note here that NA values won't have the pattern applied.
vec_fmt_partsper(num_vals, to_units = "ppm", pattern = "{x}V")
#> [1] "1,000.00 ppmV" "100.00 ppmV" "10.00 ppmV" "NA"
14-6
Other vector formatting functions:
vec_fmt_bytes(),
vec_fmt_currency(),
vec_fmt_datetime(),
vec_fmt_date(),
vec_fmt_duration(),
vec_fmt_engineering(),
vec_fmt_fraction(),
vec_fmt_integer(),
vec_fmt_markdown(),
vec_fmt_number(),
vec_fmt_percent(),
vec_fmt_scientific(),
vec_fmt_time()