First things first, open up R studio.

You should see something like the above; a window with three panes - a Console with some introductory text and a blue > prompt, an empty Enviroment and a Files browser showing the contents of the current directory.

Lets start with some very basic commands. You need to select the Console window and type after the > prompt (and type Enter after each command to execute).

In the rest of the text we will use the following conventions (which echo what you will see in your Command window):

• Commands will be shown with a preceding > prompt. Note: You must not type > in as part of the command.
• The output expected from R will be preceded by a number in square brackets (for example [1])

Basic maths

R can be used as a simple calculator. As in many programming languages, multiply is * and divide is /.

Addition

> 1 + 2

[1] 3

Division

> 1 / 2

[1] 0.5

Multiplication

> 2 * 2

[1] 4

Keeping the results of calculations

If this was the only thing R could do it would be pretty useless. We need to be able to store the results of a command with a name in order to use it again later. In programming this is called assigning a value in a variable. In R there are two commands to assign a value to a variable; <- and =. Try the following:

my_result <- 7 + 3

Note how there is now no output with square brackets. To see the value in the variable my_result use the following command:

print(my_result)

You will also see that my_result has been added to the Values section of the Environment pane (top right) in R Studio.

Help command

We have just used our first R function - print. Functions take input surrounded by brackets In the example above we used the variable my_results as input to the print function.

To get more information on how to use a function you can use ?, for example:

?print

Information on the function will be shown in the Help tab of the bottom right pane in R Studio. You can get return to the Files information at any time from the tab list.