Visualizations and the grammar of graphics

Overview

• Identify the importance of graphics in communicating information
• Define the layered grammar of graphics
• Demonstrate how to use layered grammar of graphics
• Practice generating layered graphics using ggplot2

Before class

• Required: read chapters 1 and 2 from R for Data Science. You need to read this chapter and complete some of the exercises before coming to class. Exercise solutions can be found here.
• Optional: read Hadley Wickham A Layered Grammar of Graphics – the “pre-print” version of the article can be downloaded for free. This article is optional, but I strongly encourage you to skim through it to familiarize with the theory and language of the grammar of graphics; read especially section 3 “Components of the Layered Grammar” and section 4 “A Hierarchy of Defaults.”

Additional resources

Graphical design

• Tufte, Edward R. The Visual Display of Quantitative Information. Classic book on statistical graphics and visualization design.
• Healey, Kieran. Data Visualization: A Practical Guide. An applied introduction to graphical design with lots of applications in ggplot2 and many code examples.

ggplot2

• ggplot2: Elegant Graphics for Data Analysis, 2nd Edition – Hadley Wickham. Excellent resource for learning the intricacies of ggplot2.
• Documentation for ggplot2.
• R Graphics Cookbook, 2nd edition – Winston Chang. A practical guide with 150 examples to generate quality statistical graphics based on the data you wish to present.

Cheatsheets

• Data visualization with ggplot2 cheat sheet
• RStudio IDE Cheat Sheet
• Rmarkdown Cookbook

What you need to do after class

• Complete Assigment 1 and submit the link to your repo on Canvas so we can grade it
• Review today’s lecture and prepare for next class