This guide can stack other position guides that represent position scales, like those created with scale_(x|y)_continuous() and scale_(x|y)_discrete().
A position guide given as one of the following:
A string, for example "axis".
A call to a guide function, for example guide_axis().
Additional guides to stack given in the same manner as first.
A character string or expression indicating a title of guide.
If NULL, the title is not shown. By default
(waiver()), the name of the scale object or the name
specified in labs() is used for the title.
A theme object to style the guide individually or
differently from the plot's theme settings. The theme argument in the
guide partially overrides, and is combined with, the plot's theme.
A unit() objects that determines how far separate guides are
spaced apart.
A positive integer of length 1 that specifies the order of
this guide among multiple guides. This controls in which order guides are
merged if there are multiple guides for the same position. If 0 (default),
the order is determined by a secret algorithm.
Where this guide should be drawn: one of top, bottom, left, or right.
The first guide will be placed closest to the panel and any subsequent
guides provided through ... will follow in the given order.
# A standard plot
p <- ggplot(mpg, aes(displ, hwy)) +
geom_point() +
theme(axis.line = element_line())
# A normal axis first, then a capped axis
p + guides(x = guide_axis_stack("axis", guide_axis(cap = "both")))