annotate_arrow {ggarrow}

Arrow annotation layer

Description

This function mirrors annotate() with the following changes. First, the geom argument is pre-populated with "arrow". Second, several parameters from ggarrow are special-cased, because no warning needs to be issued when they don't have length 1.

Usage

annotate_arrow(
  geom = "arrow",
  x = NULL,
  y = NULL,
  xmin = NULL,
  xmax = NULL,
  ymin = NULL,
  ymax = NULL,
  xend = NULL,
  yend = NULL,
  ...,
  na.rm = FALSE
)

Arguments

geom

name of geom to use for annotation

x, y, xmin, ymin, xmax, ymax, xend, yend

Positioning aesthetics. At least one of these must be specified.

...

Other arguments passed on to layer()'s params argument. These arguments broadly fall into one of 4 categories below. Notably, further arguments to the position argument, or aesthetics that are required can not be passed through .... Unknown arguments that are not part of the 4 categories below are ignored.

• Static aesthetics that are not mapped to a scale, but are at a fixed value and apply to the layer as a whole. For example, colour = "red" or linewidth = 3. The geom's documentation has an Aesthetics section that lists the available options. The 'required' aesthetics cannot be passed on to the params. Please note that while passing unmapped aesthetics as vectors is technically possible, the order and required length is not guaranteed to be parallel to the input data.

• When constructing a layer using a ⁠stat_*()⁠ function, the ... argument can be used to pass on parameters to the geom part of the layer. An example of this is stat_density(geom = "area", outline.type = "both"). The geom's documentation lists which parameters it can accept.

• Inversely, when constructing a layer using a ⁠geom_*()⁠ function, the ... argument can be used to pass on parameters to the stat part of the layer. An example of this is geom_area(stat = "density", adjust = 0.5). The stat's documentation lists which parameters it can accept.

• The key_glyph argument of layer() may also be passed on through .... This can be one of the functions described as key glyphs, to change the display of the layer in the legend.

na.rm

If FALSE, the default, missing values are removed with a warning. If TRUE, missing values are silently removed.

Value

A ⁠<Layer>⁠ ggproto object that can be added to a plot.

See Also

Other arrow geoms: geom_arrow(), geom_arrow_chain(), geom_arrow_curve(), geom_arrow_segment()

Examples

# Annotate an arrow
ggplot() +
  annotate_arrow(
    x = c(0, 1), y = c(0, 1),
    arrow_head = arrow_head_line(),
    arrow_fins = arrow_fins_line(),
    length_head = unit(5, "mm"),
    length_fins = unit(5, "mm")
  )

# Still works with other geoms as well
ggplot(mtcars, aes(x = wt, y = mpg)) + geom_point() +
  annotate_arrow("text", x = 4, y = 25, label = "Some text")