• RStudio is the most common way of interacting with R
• We can save all of our commands in a single file (Reproducible Research)
• We can view a summary of our objects, make plots, import & export data etc.

• R Projects are not compulsory, but are VERY useful!
• Just a simple wrapper to help keep an analysis/workshop organised
• When we open an R Project, we go back to the last state (i.e. where we were last time)
• Also great for interacting with version control (e.g. git)

Let's set one up for this course: File > New Project

• Choose either a New or Existing Directory
• Navigate to somewhere you think is suitable for keeping the course notes
• The project name will automatically be assigned as the directory name
• (These need to match)

1. File > New File > R Script
   
2. Save As Introduction.R

• Note that the directory of the project was the automatic directory opened to save the file
• This is your working directory

getwd()

• This is just a simple text editor.
• We enter our commands here but they are not executed
  • We can keep a record of everything we've done
  • We can also add comments to our code
  • Comments start with the # symbol
  • RStudio will automatically colour our code for easy reading

• Where we execute commands
• Is essentially the "engine"
• We can execute commands directly in the Console or send from the Script Window

Enter the following in the Script Window

# Create an example R object
x <- 5

• We have not sent this to R yet!
  • Only the plain text exists in the Script Window

• Lines of code are sent to the Console by either:
  • Ctrl + Enter
  • Copy & Paste into the Console
  • Clicking the Run button at the top right
• Try this with your code

We can view the contents of the object x by:

• entering it's name directly in the Console, or
• entering it's name in the Script Window & sending it to the Console

x
print(x)

Where have we created the object x?

• Is it on your hard drive somewhere?
• Is it in a file somewhere?

• We have placed x in our R Workspace
• More formally known as your Global Environment

• The Environment is like your desktop
• We keep all our relevant objects here and can save all the objects in your workspace as an .RData object

save.image()

• Just like in Excel, we save a workbook with multiple sheets
• Here we save a workspace with multiple objects
• And we can save the code use to create these objects!

• Next to the Environment Tab is the History Tab
  • Contains everything executed in the Console
  • Useful for when we've been lazy
• Best coding practice is still to enter code in the Script Window and execute

In the bottom right are a series of tabs

1. Files: This shows your current working directory
2. Plots: Every time you make a graph it appears here
3. Packages: NEVER CLICK OR UN-CLICK ANYTHING HERE
4. Help: We'll explore this later

• Every tab can be resized using the buttons in the top right
• Window separators can also be be moved

Help > Cheatsheets > RStudio IDE Cheat Sheet

Page 2 has lots of hints:

• Ctrl + 1 places focus on the Script Window
• Ctrl + 2 places focus on the Console
• Ctrl + 3 places focus on the Help Tab

Next:

Session 2 - Loading data into R