3) Set a Working Directory

This Blog entry is from the Getting Started in R section in Learn R.

A working directory is where R will look for files during a session.  The files may be the R session, or in subsequent Blog entries it will be data to be imported and data saved as the result of processing. 

In Blog entry Issue commands to the R Console, it was observed that there was a failure when saving the R history, owing to the working directory not being set (rather set incorrectly).  It follows that the working directory need be set.

Start by executing Blog Entry Navigate to and launch the R command line to load the R console.


To identify the current working directory use the getwd() function, type the script line:



Execute the command by pressing the Enter key:


The current working directory, which is the directory containing the executable, is returned.  Saving files to the same directory as the R software is not desirable, quite beyond it causing errors, and as such, this should be changed to an appropriate directory.

Create a directory to be used throughput these Blog entries.  In this case the files will be saved to the d:\ in a directory called R.


To set this as the working directory in R use the setwd() function with the directory in quotation marks, type:


  Press the Enter key to process the line of script:


The absence of any error message confirms that the working directory has been changed, although this can be affirmed by executing the getwd() function:


The working directory is now set to d:\r.

If R is exited, and y is selected to save, it can be observed that there were no errors:


Furthermore, it can be seen that the .RHistory file has been saved to the working directory:


2) Issue commands to the R Console.

This Blog entry is from the Getting Started in R section in Learn R.

R is an interpreted language for mathematical and statistical computing. R processes as script, line by line.  In this example the sum of 1 + 1 will be returned, which will of course be 2.  To perform such a calculation type:


Press the Enter key to commit and execute the line of script:


It can be seen that a line has been returned showing [1] 2, where [1] is the position in the result vector, where 2 is the actual value returned from the line of script.  The mathematical operators (in this case +) are much the same as Excel:

·         + Addition.

·         - Subtract

·         / Divide

·         * Multiply

This Blog entry has shown a simple line of script being written, executed and returned by R.  Although rudimentary, it is an R program.

To exit the R console, hold down the CTRL key and the D key:


There are three options presented when exiting the R console:

·         y: Save the workspace image for reloading.  This will keep everything in the current session.

·         n: Clear the workspace so that the next time r is loaded it will be afresh.

·         c: Cancel and go back to the workspace.

In this example, type:


Press the Enter key to commit the command:


Notice that an error was returned ‘Unable to open .Rhistory’.  The error is created as the operating system will not allow the user to write to the same directory as R is running, which introduces the concept of working directories, as follows.