How to customize annotations in ggplot2-CodePudding

Recently, I have been trying to add some text annotations to ggplot2 graphs using annotate() function. Here is a basic example;

p <- ggplot(mtcars, aes(x = wt, y = mpg))   geom_point()
p   annotate("text", x = 4, y = 25, label = "Some text")

The problem I am facing in using annotate() function is related to its customization. In other words, when I try to customize the text I want to add on the graph using basic CSS, Some text, such as changing the color and font size of text word, it does not allow me to do so. Therefore, I want to inquire how I can customize text annotations I want to put on the ggplot2 graphs? Thank you for your attention beforehand.

CodePudding user response：

If you look at ?geom_text you will see the aesthetics that can be applied to a text layer. The main ones are demonstrated below:

p   annotate("text", x = 4, y = 25, label = "Some text",
             color    = "red",
             size     = 15, 
             family   = "serif", 
             fontface = "bold")

If you are desperate to use css instead of passing parameters to annotate, you could try loading the ggtext package and using annotation with geom = "richtext" instead of geom = "text". It only covers a small subset of css (essentially just those properties shown above and one or two others)

library(ggtext)

p   annotate(geom = 'richtext', x = 4, y = 25, color = NA, fill = NA,
             label='<span style="color:red; font-size:15mm; font-family:serif;">
                    <b>Some text</b></span>')