Data visualization with ggplot2

• Authors: Ahmed Hasan and James Santangelo
• Research field: Biology
• Lesson topic: Data visualization in R with ggplot2
• Lesson content URL: https://github.com/utm-coders/studyGroup/tree/gh-pages/lessons/r/ggplot2

Preface:

This is an introduction to data visualization in R with the ggplot2 package. It is based partially on openly available material from Data Carpentry and EEB313. This lesson covers most standard kinds of plots used in biological research, such as scatter plots and histograms before discussing plot customization, faceting, and other intermediate topics.

The lesson assumes knowledge of some of the material covered in our Intro to R lesson, such as familiarity with the R/RStudio interface, as well as objects and functions.

We will be working through the material together in RStudio rstudio using the R Notebook r-notebook file format. To use RStudio, you will also have to download standalone R here.

Please make sure to have tidyverse and patchwork installed:

install.packages('tidyverse')
install.packages('patchwork')

Lesson Overview:

The lesson covers:

• Creating standard plots with ggplot2
  • Scatter plots (with legends)
  • Line plots
  • Histograms
• Modifying themes
  • Default themes
  • The element family
• Faceting
• Composing multiple plots with patchwork
• Annotating plots
  • Model fits with geom_smooth
  • Adding text (e.g. model coefficients) to a plot