/ Data Visualization

Improved text rendering support for ggplot2

Improved text rendering support for ggplot2

ggtext

Improved text rendering support for ggplot2, written by Claus O. Wilke

This package provides ggplot2 support for the gridtext package, which implements rich-text (basic HTML and Markdown) rendering for the grid graphics engine. It is a work in progress. Many obvious features are missing, and others have bugs or don’t work in corner cases.

Installation

devtools::install_github("clauswilke/ggtext")

Examples

Rich text formatting support is provided both in theme elements and via
geoms.

Markdown in theme elements

The ggtext package defines a new theme element, element_markdown(),
which behaves similarly to element_text() but renders the provided
text as markdown/html. Note that word wrapping is disabled by
element_markdown(). To start a new line, use the <br> tag or add two
spaces before the end of a line.

library(ggplot2)
library(ggtext)

ggplot(iris, aes(Sepal.Length, Sepal.Width, color = Species)) +
  geom_point(size = 3) +
  scale_color_manual(
    name = NULL,
    values = c(setosa = "#0072B2", virginica = "#009E73", versicolor = "#D55E00"),
    labels = c(
      setosa = "<i style='color:#0072B2'>I. setosa</i>",
      virginica = "<i style='color:#009E73'>I. virginica</i>",
      versicolor = "<i style='color:#D55E00'>I. versicolor</i>")
  ) +
  labs(
    title = "**Fisher's *Iris* dataset**  
    <span style='font-size:11'>Sepal width vs. sepal length for three *Iris*
    species</span>",
    x = "Sepal length (cm)", y = "Sepal width (cm)"
  ) +
  theme_minimal() +
  theme(
    plot.title = element_markdown(lineheight = 1.1),
    legend.text = element_markdown(size = 11)
  )

ggtext

Very basic support for the <img> tag exists, and it can be used, for
example, to employ images as axis labels.

labels <- c(
  setosa = "<img src='https://upload.wikimedia.org/wikipedia/commons/thumb/8/86/Iris_setosa.JPG/180px-Iris_setosa.JPG'
    width='100' /><br>*I. setosa*",
  virginica = "<img src='https://upload.wikimedia.org/wikipedia/commons/thumb/3/38/Iris_virginica_-_NRCS.jpg/320px-Iris_virginica_-_NRCS.jpg'
    width='100' /><br>*I. virginica*",
  versicolor = "<img src='https://upload.wikimedia.org/wikipedia/commons/thumb/2/27/20140427Iris_versicolor1.jpg/320px-20140427Iris_versicolor1.jpg'
    width='100' /><br>*I. versicolor*"
)

ggplot(iris, aes(Species, Sepal.Width)) +
  geom_boxplot() +
  scale_x_discrete(
    name = NULL,
    labels = labels
  ) +
  theme(
    axis.text.x = element_markdown(color = "black", size = 11)
  )

README-unnamed-chunk-4-1

Geoms

The geom geom_rich_text() provides markdown/html labels. Unlike
geom_label(), the labels can be rotated.

df <- data.frame(
  label = 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:18; color:black'>large</span> text."
  ),
  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")
)


ggplot(df) +
  aes(
    x, y, label = label, angle = angle, color = color, fill = fill,
    hjust = hjust, vjust = vjust
  ) +
  geom_rich_text() +
  geom_point(color = "black", size = 2) +
  scale_color_identity() +
  scale_fill_identity() +
  xlim(0, 1) + ylim(0, 1)

README-unnamed-chunk-5-1

Labels without frame or background are also possible.

ggplot(df) +
  aes(
    x, y, label = label, angle = angle, color = color,
    hjust = hjust, vjust = vjust
  ) +
  geom_rich_text(
    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)

README-unnamed-chunk-6-1

GitHub