Mapping data to graphics

Lesson for Monday, September 4, 2023–Friday, September 8, 2023

Part 1: Data visualization with {ggplot2}

For the first part of this week’s lesson, you need to work through RStudio’s introductory primers for {ggplot2}. You’ll do these in your browser and type code and see results there.

It seems like there are a lot, but they’re short and go fairly quickly (especially as you get the hang of the ggplot() syntax). Complete these:

• Visualize Data
  • Exploratory Data Analysis
  • Bar Charts
  • Histograms
  • Boxplots and Counts
  • Scatterplots
  • Line plots
  • Overplotting and Big Data
  • Customize Your Plots

Part 2: Reshaping data with {tidyr}

For the last part of this week’s lesson, you’ll work through just one RStudio primer to learn how to use the {tidyr} package to reshape data from wide to long and back to wide.

Complete this:

• Tidy Your Data
  • Reshape Data

Pivoting

Newer versions of {tidyr} have renamed these core functions: gather() is now pivot_longer() and spread() is now pivot_wider(). The syntax for these pivot_*() functions is slightly different from what it was in gather() and spread(), so you can’t just replace the names. Fortunately, both gather() and spread() still work and won’t go away for a while, so you can still use them as you learn about reshaping and tidying data. It would be worth learning how the newer pivot_*() functions work, eventually, though (see here for examples).