Label percentages (2.5%, 50%, etc)

## Usage

```
label_percent(
accuracy = NULL,
scale = 100,
prefix = "",
suffix = "%",
big.mark = " ",
decimal.mark = ".",
trim = TRUE,
...
)
```

## Arguments

- accuracy
A number to round to. Use (e.g.)

`0.01`

to show 2 decimal places of precision. If`NULL`

, the default, uses a heuristic that should ensure breaks have the minimum number of digits needed to show the difference between adjacent values.Applied to rescaled data.

- scale
A scaling factor:

`x`

will be multiplied by`scale`

before formatting. This is useful if the underlying data is very small or very large.- prefix
Additional text to display before the number. The suffix is applied to absolute value before

`style_positive`

and`style_negative`

are processed so that`prefix = "$"`

will yield (e.g.)`-$1`

and`($1)`

.- suffix
Additional text to display after the number.

- big.mark
Character used between every 3 digits to separate thousands.

- decimal.mark
The character to be used to indicate the numeric decimal point.

- trim
Logical, if

`FALSE`

, values are right-justified to a common width (see`base::format()`

).- ...
Arguments passed on to

`label_number`

`style_positive`

A string that determines the style of positive numbers:

`"none"`

(the default): no change, e.g.`1`

.`"plus"`

: preceded by`+`

, e.g.`+1`

.`"space"`

: preceded by a Unicode "figure space", i.e., a space equally as wide as a number or`+`

. Compared to`"none"`

, adding a figure space can ensure numbers remain properly aligned when they are left- or right-justified.

`style_negative`

A string that determines the style of negative numbers:

`"hyphen"`

(the default): preceded by a standard hypen`-`

, e.g.`-1`

.`"minus"`

, uses a proper Unicode minus symbol. This is a typographical nicety that ensures`-`

aligns with the horizontal bar of the the horizontal bar of`+`

.`"parens"`

, wrapped in parentheses, e.g.`(1)`

.

`scale_cut`

Named numeric vector that allows you to rescale large (or small) numbers and add a prefix. Built-in helpers include:

`cut_short_scale()`

: [10^3, 10^6) = K, [10^6, 10^9) = M, [10^9, 10^12) = B, [10^12, Inf) = T.`cut_long_scale()`

: [10^3, 10^6) = K, [10^6, 10^12) = M, [10^12, 10^18) = B, [10^18, Inf) = T.`cut_si(unit)`

: uses standard SI units.

If you supply a vector

`c(a = 100, b = 1000)`

, absolute values in the range`[0, 100)`

will not be rescaled, absolute values in the range`[100, 1000)`

will be divided by 100 and given the suffix "a", and absolute values in the range`[1000, Inf)`

will be divided by 1000 and given the suffix "b". If the division creates an irrational value (or one with many digits), the cut value below will be tried to see if it improves the look of the final label.

## Value

All `label_()`

functions return a "labelling" function, i.e. a function that
takes a vector `x`

and returns a character vector of `length(x)`

giving a
label for each input value.

Labelling functions are designed to be used with the `labels`

argument of
ggplot2 scales. The examples demonstrate their use with x scales, but
they work similarly for all scales, including those that generate legends
rather than axes.

## See also

Other labels for continuous scales:
`label_bytes()`

,
`label_currency()`

,
`label_number_auto()`

,
`label_number_si()`

,
`label_ordinal()`

,
`label_parse()`

,
`label_pvalue()`

,
`label_scientific()`

## Examples

```
demo_continuous(c(0, 1))
#> scale_x_continuous()
demo_continuous(c(0, 1), labels = label_percent())
#> scale_x_continuous(labels = label_percent())
# Use prefix and suffix to create your own variants
french_percent <- label_percent(
decimal.mark = ",",
suffix = " %"
)
demo_continuous(c(0, .01), labels = french_percent)
#> scale_x_continuous(labels = french_percent)
```