Graph customization

Once you have a basic graph, you may want to further alter its appearance. Some common customizations include:

• changing axis labels, titles, and captions (using labs())
• specifying colors within the graph (e.g. with scale_fill_manual)
• applying a theme() to the graph, changing its overall appearance (e.g. theme_dark(), theme_bw(), theme_classic(),theme_minimal()

You can also change individual aspects of your them inside of the theme() call. For specifics of working with theme(), see the ggplot2 documentation.

To see these customizations in action, start with the scatterplot showing penguin bill length and body mass by island (created above), and add a few lines to change title, color, and labels:

ggplot(data = penguins, 
       mapping = aes(x = bill_length_mm, y = body_mass_g, color = island)) +
  geom_point(alpha = 0.7) +
  scale_color_manual(values = c("magenta3", "darkorange", "blue4")) +
  labs(x = "Bill length (mm)",
       y = "Body mass (g)",
       title = "Palmer Penguins",
       subtitle = "Examining penguin body mass and bill length") + 
  theme_bw()

To read more about ggplot2, see the R for Data Science chapter about data visualization. More extensive documentation can be found on the ggplot2 website.