ggh4x (version 0.2.8)

geom_text_aimed: Aimed text

Description

Similar to geom_text(), this geom also generates text but places the text at an angle so that the text seems aimed towards a point defined by [xend, yend].

Usage

geom_text_aimed(
  mapping = NULL,
  data = NULL,
  stat = "identity",
  position = "identity",
  ...,
  parse = FALSE,
  nudge_x = 0,
  nudge_y = 0,
  flip_upsidedown = TRUE,
  check_overlap = FALSE,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

Value

A ggplot2 Layer that can be added to a plot.

Arguments

mapping

Set of aesthetic mappings created by aes(). If specified and inherit.aes = TRUE (the default), it is combined with the default mapping at the top level of the plot. You must supply mapping if there is no plot mapping.

data

The data to be displayed in this layer. There are three options:

If NULL, the default, the data is inherited from the plot data as specified in the call to ggplot().

A data.frame, or other object, will override the plot data. All objects will be fortified to produce a data frame. See fortify() for which variables will be created.

A function will be called with a single argument, the plot data. The return value must be a data.frame, and will be used as the layer data. A function can be created from a formula (e.g. ~ head(.x, 10)).

stat

The statistical transformation to use on the data for this layer, either as a ggproto Geom subclass or as a string naming the stat stripped of the stat_ prefix (e.g. "count" rather than "stat_count")

position

Position adjustment, either as a string, or the result of a call to a position adjustment function. Cannot be jointly specified with nudge_x or nudge_y.

...

Other arguments passed on to layer(). These are often aesthetics, used to set an aesthetic to a fixed value, like colour = "red" or size = 3. They may also be parameters to the paired geom/stat.

parse

If TRUE, the labels will be parsed into expressions and displayed as described in ?plotmath.

nudge_x, nudge_y

Horizontal and vertical adjustment to nudge labels by. Useful for offsetting text from points, particularly on discrete scales. Cannot be jointly specified with position.

flip_upsidedown

A logical(1). If TRUE (default), the angle of text placed at angles between 90 and 270 degrees is flipped so that it is more comfortable to read. If FALSE, will take calculated angles literally.

check_overlap

If TRUE, text that overlaps previous text in the same layer will not be plotted. check_overlap happens at draw time and in the order of the data. Therefore data should be arranged by the label column before calling geom_text(). Note that this argument is not supported by geom_label().

na.rm

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

show.legend

logical. Should this layer be included in the legends? NA, the default, includes if any aesthetics are mapped. FALSE never includes, and TRUE always includes. It can also be a named logical vector to finely select the aesthetics to display.

inherit.aes

If FALSE, overrides the default aesthetics, rather than combining with them. This is most useful for helper functions that define both data and aesthetics and shouldn't inherit behaviour from the default plot specification, e.g. borders().

Aesthetics

geom_text_aimed() understands the following aesthetics (required aesthetics are in bold):

• x

• y

• label

• alpha

• angle

• colour

• family

• fontface

• group

• hjust

• lineheight

• size

• vjust

• xend

• yend

Learn more about setting these aesthetics in vignette("ggplot2-specs").

Details

The calculated angle is such that the text will be parallel to a line passing through the coordinates [x, y] and [xend, yend]. The calculated angle is added to the angle angle aesthetic, so that you can set text perpendicular to that line by setting angle = 90. These angles are calculated in absolute coordinates, meaning that resizing the plot will retain the same appearance.

Examples

# Point all labels to upper right corner
ggplot(mtcars, aes(mpg, wt)) +
  geom_text_aimed(aes(label = rownames(mtcars)),
                  xend = Inf, yend = Inf)

# Point all labels to center of polar plot
ggplot(mpg, aes(manufacturer)) +
  geom_bar(width = 1, aes(fill = manufacturer), show.legend = FALSE) +
  geom_text_aimed(aes(label = manufacturer), hjust = 0,
                  stat = "count", nudge_y = 2) +
  scale_x_discrete(labels = NULL) +
  coord_polar()