Chapter 1 Before we start

This is a two part intro to R workshop. Part I introduces the basics of coding in R, including how to manipulate objects, use functions, and write if statements, for loops, and simple functions. Part II is based on the tidyverse package, and it covers how to load, inspect, and explore data in R. While learners at different expertise levels are welcome to attend, these workshops were designed for participants with no or little programming experience.

This lesson plan was created based on many other resources that are already available online, mainly Claudia A Engel’s “Introduction to R” bookdown available at https://cengel.github.io/R-intro and “Programming with R” from Software Carpentry available at http://swcarpentry.github.io/r-novice-inflammation.

1.1 Installing R and R Studio

If you are running your R code in your computer, you need to install both R and RStudio. Alternatively, you can create a free account at http://rstudio.cloud and run your R code in the cloud. Either way, we will be using the same IDE (i.e., RStudio).

What’s an IDE? IDE stands for integrated development environment, and its goal is to facilitate coding by integrating a text editor, a console and other tools into one window.

1.1.1 I’ve never installed R and RStudio in my computer OR I’m not sure I have R and RStudio installed in my computer

  1. Download and install R from https://cran.r-project.org
  2. Download and install RStudio from https://rstudio.com/products/rstudio/download/#download

1.1.2 I already have R and RStudio installed

  1. Open RStudio
  2. Check your R version by entering sessionInfo() on your console.
  3. The latest release for R was April 24, 2020 (R version 4.0.0, 2020-04-24, Arbor Day). If your R version is older than the most recent version, please follow step 1 in the previous section to update R.
  4. Check your RStudio version, if your version is older than Version 1.2.5042, please follow step 2 in the previous section to update RStudio.

How often should I update R and RStudio? Always make sure that you have the latest version of R, RStudio, and the packages you’re using in your code to ensure you are not running into bugs that are caused by having older versions installed in your computer.

When asked, Jenny Bryan summarizes the importance of keeping your system up-to-date saying that “You will always eventually have a reason that you must update. So you can either do that very infrequently, suffer with old versions in the middle, and experience great pain at update. Or admit that maintaining your system is a normal ongoing activity, and do it more often.”

You can ensure your packages are also up-to-date by clicking on “Tools” on your RStudio top menu bar, and selecting “Check for Packages Updates…”