label_parse()
produces expression from strings by parsing them;
label_math()
constructs expressions by replacing the pronoun .x
with each string.
label_parse()
label_math(expr = 10^.x, format = force)
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.
plotmath for the details of mathematical formatting in R.
Other labels for continuous scales:
label_bytes()
,
label_currency()
,
label_number_auto()
,
label_number_si()
,
label_ordinal()
,
label_percent()
,
label_pvalue()
,
label_scientific()
Other labels for discrete scales:
label_wrap()
# Use label_parse() with discrete scales
greek <- c("alpha", "beta", "gamma")
demo_discrete(greek)
#> scale_x_discrete()
demo_discrete(greek, labels = label_parse())
#> scale_x_discrete(labels = label_parse())
# Use label_math() with continuous scales
demo_continuous(c(1, 5))
#> scale_x_continuous()
demo_continuous(c(1, 5), labels = label_math(alpha[.x]))
#> scale_x_continuous(labels = label_math(alpha[.x]))
demo_continuous(c(1, 5), labels = label_math())
#> scale_x_continuous(labels = label_math())