automatic-partial-functions {ggdist} | R Documentation |
Several ggdist functions support automatic partial application: when called, if all of their required arguments have not been provided, the function returns a modified version of itself that uses the arguments passed to it so far as defaults. Technically speaking, these functions are essentially "Curried" with respect to their required arguments, but I think "automatic partial application" gets the idea across more clearly.
Functions supporting automatic partial application include:
The point_interval()
family, such as median_qi()
, mean_qi()
,
mode_hdi()
, etc.
The smooth_
family, such as smooth_bounded()
, smooth_unbounded()
,
smooth_discrete()
, and smooth_bar()
.
The density_
family, such as density_auto()
, density_bounded()
and
density_unbounded()
.
Partial application makes it easier to supply custom parameters to these
functions when using them inside other functions, such as geoms and stats.
For example, smoothers for geom_dots()
can be supplied in one of three
ways:
as a suffix: geom_dots(smooth = "bounded")
as a function: geom_dots(smooth = smooth_bounded)
as a partially-applied function with options:
geom_dots(smooth = smooth_bounded(kernel = "cosine"))
The density
argument to stat_slabinterval()
works similarly with the
density_
family of functions.
set.seed(1234) x = rnorm(100) # the first required argument, `x`, of the density_ family is the vector # to calculate a kernel density estimate from. If it is not provided, the # function is partially applied and returned as-is density_auto() # we could create a new function that uses half the default bandwidth density_half_bw = density_auto(adjust = 0.5) density_half_bw # we can overwrite partially-applied arguments density_quarter_bw_trimmed = density_half_bw(adjust = 0.25, trim = TRUE) density_quarter_bw_trimmed # when we eventually call the function and provide the required argument # `x`, it is applied using the arguments we have "saved up" so far density_quarter_bw_trimmed(x)