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.
Arguments
digits
Number of digits to show before exponent.
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, suffix
Symbols to display before and after value.
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()).