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 chapter 3 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.”

Class materials

• Why visualize data?
• The Grammar of Graphics
• Practice generating graphics with ggplot2

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 Homework 1 and submit the link to your repo on Canvas so we can grade it
• Review today’s lecture and prepare for next class
• This applies only if you installed your software locally:
  • Install the rcis library from GitHub. To install it run the command remotes::install_github("CFSS-MACSS/rcis") in the console. We will be using data from this package in class.
  • Notice: if you do not already have the remotes library installed, you will get an error. Go back and install this first using install.packages("remotes"), then run remotes::install_github("CFSS-MACSS/rcis") in the console.