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Stat 230 Notes

B The R enviroment

B.1 Workspace

Anything that you load or create in Rstudio (data, vectors, models) are called objects. You can see your current objects in your RStudio Environment pane (upper right). These objects, along with your command history, are contained in what R calls your “Workspace.”

When you exit Rstudio, you may be asked if you want to save your workspace as a .RData file before exiting. I strongly encourage you not to do this since it can make it very hard to reproduce your workflow (and it can slow down Rstudio start up). Instead, use R markdown (Chapter D) to document your workflow so you can redo any analysis that you’ve previously done.

To change Rstudio’s default startup and exit workspace behavior:

  • From the Tools drop down menu (at the top), select Global Options…
  • Under the General tab, uncheck the “Restore .RData into workspace at startup”
  • In the “Save workspace to .RData on exit:” dropdown, select Never

B.2 Working directory

The default location that R looks for “stuff” or saves “stuff” is called your Working Directory. For example, the default location of this folder is typically your Documents folder for a Windows machine. You can run the getwd() command to see where your current working directory is located. For my desktop Windows computer, the default working directory location is

> getwd()
[1] "C:/Users/kstclair/Documents"

Or from the maize server,

> getwd()
[1] "/Accounts/kstclair"

B.3 Rstudio projects

RStudio (not standalone R) has a feature called Projects that make it easy to start RStudio in a particular working directory. You can create different Projects for different classes (or research projects).

Your first task in Rstudio for Stat 230 will be to create a Stat 230 project:

  1. Find the Project button in the upper right-hand corner of Rstudio. Select New Project.
  2. Click New Directory from the New Project dialog box.
  1. Click on New project (again), then enter Stat230 as your Directory name (no spaces). Use the Browse button to put this project in a good spot on your computer or accept the default location on maize.
  2. Click on Create Project. Your Rstudio session should not change in looks all that much but check your computer should now contain a Stat230 folder in the location you chose. This folder will contain a Stat230.Rproj icon.
  3. Your working directory is now set to this Stat230 folder. Check this with the getwd() command.

Starting your Stat230 project:

  1. Rstudio default settings are to start up your last project when you reopen Rstudio. So just opening Rstudio (or loggin onto maize) usually opens your Stat230 project. You will see your project name in the upper right-hand project button location.
  2. Alternatively, start your R project by double clicking on the project icon in your Stat230 folder. You will know you are in
  3. You can also open or change projects with the drop-down project menu.
> knitr::opts_chunk$set(echo = TRUE, eval=TRUE, prompt=FALSE, collapse = FALSE, 
+                       message = FALSE, warning = FALSE)