Richtext labels

This geom draws text labels similar to ggplot2::geom_label(), but formatted using basic markdown/html. Parameter and aesthetic names follow the conventions of ggplot2::geom_label(), and therefore the appearance of the frame around the label is controlled with label.colour, label.padding, label.margin, label.size, label.r, even though the same parameters are called box.colour, box.padding, box.margin, box.size, and box.r in geom_textbox(). Most styling parameters can be used as aesthetics and can be applied separately to each text label drawn. The exception is styling parameters that are specified as grid units (e.g., label.padding or label.r), which can only be specified for all text labels at once. See examples for details.

geom_richtext2(
  mapping = NULL,
  data = NULL,
  stat = "identity",
  position = "identity",
  ...,
  nudge_x = 0,
  nudge_y = 0,
  label.padding = unit(c(0.25, 0.25, 0.25, 0.25), "lines"),
  label.margin = unit(c(0, 0, 0, 0), "lines"),
  label.r = unit(0.15, "lines"),
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

Arguments

mapping

Set of aesthetic mappings created by aes() or 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, as a string.

position

Position adjustment, either as a string, or the result of a call to a position adjustment function. Cannot be jointy 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.

nudge_x

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

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.

label.padding

Amount of padding around label. Defaults to 0.25 lines.

label.margin

Unit vector of length four specifying the margin outside the text label.

label.r

Radius of rounded corners. Defaults to 0.15 lines.

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().

Value

A ggplot2 layer that can be added to a plot created with ggplot2::ggplot().

Aesthetics

geom_richtext() understands the following aesthetics (required aesthetics are in bold; select aesthetics are annotated):

  • x

  • y

  • label

  • alpha

  • angle

  • colour Default color of label text and label outline.

  • family

  • fontface

  • fill Default fill color of label background.

  • group

  • hjust

  • label.colour Color of label outline. Overrides colour.

  • label.size Width of label outline.

  • lineheight

  • size Default font size of label text.

  • text.colour Color of label text. Overrides colour.

  • vjust

Examples

library(ggplot2)

labels1 = c(
  "Some text **in bold.**",
  "Linebreaks<br>Linebreaks<br>Linebreaks",
  "*x*<sup>2</sup> + 5*x* + *C*<sub>*i*</sub>",
  "Some <span style='color:blue'>blue text **in bold.**</span><br>And *italics text.*<br>
    And some <span style='font-size:18pt; color:black'>large</span> text."
)

labels2 <- c(
  "gC m^{-2} d^{-1}",
  "gC m^-2 d^-1",
  "gC m_{-2} d_{-1}",
  "gC m_-2 d_-1"
  # "gC \n mm/d"
)

df <- data.frame(
  x = c(.2, .1, .5, .9),
  y = c(.8, .4, .1, .5),
  hjust = c(0.5, 0, 0, 1),
  vjust = c(0.5, 1, 0, 0.5),
  angle = c(0, 0, 45, -45),
  color = c("black", "blue", "black", "red"),
  fill = c("cornsilk", "white", "lightblue1", "white")
)

fun <- function(labels) {
  df$label = labels
  ggplot(df, aes(x, y, label = label, angle = angle, color = color,
                 hjust = hjust, vjust = vjust)) +
    geom_richtext2(
      fill = NA, label.color = NA, # remove background and outline
      label.padding = grid::unit(rep(0, 4), "pt") # remove padding
    ) +
    geom_point(color = "black", size = 2) +
    scale_color_identity() +
    xlim(0, 1) +
    ylim(0, 1)
}
fun(labels1)

fun(labels2)

# labels without frame or background are also possible