Package

For this post, we need the ggplot2 and geomtextpath packages.

# Install the packages if not already done
# install.packages("ggplot2")
# install.packages("geomtextpath")

# Load the package
library(ggplot2)
library(geomtextpath)

Default density chart in ggplot2

Here’s what the default density chart output looks like with ggplot2:

Add labels

With the geom_textdensity() function (inspired from the geom_density() func from ggplot2), we can add the label of species directly on each density line.

library(hrbrthemes)
data(iris)

ggplot(iris, aes(x = Sepal.Length, colour = Species, label = Species)) +
  geom_textdensity() +
  theme_bw() + guides(color = 'none')

Change texts properties

The geom_textdensity() can take multiple arguments in order to change the properties of the labels:

size: size of the text
fontface: style of the font
vjust: vertical adjustment
hjust: horizontal adjustment

The 2 last arguments can either be float (generally between -1 and 1) or string such as xmid (or ymid), xmax (or ymax) and auto (default).

library(hrbrthemes)
data(mtcars)

mtcars$labels = ifelse(mtcars$vs==0, "Type 0", "Type 1")
ggplot(mtcars, aes(x = qsec, colour = as.factor(labels), label = as.factor(labels))) +
  geom_textdensity(size = 6, fontface = 4, # size of 6, bold italic
                   vjust = -0.4, hjust = "ymid") +
  theme_bw() + guides(color = 'none')

Conclusion

In this post, we look at how to use the geomtexpath package to create density plot with text. To find out more about how to customize a density plot, see the dedicated section.

Contact

This document is a work by Yan Holtz. Any feedback is highly encouraged. You can fill an issue on Github, drop me a message on Twitter, or send an email pasting yan.holtz.data with gmail.com.

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