If for whatever reason there is an issue using the R environment during your examination, please immediately alert a proctor by raising your hand. Make sure to file an incident report with the proctor prior to leaving the testing facility.
For more information, please see the FAQ item Problems During the Test.
To access RStudio in the Computer-Based Testing Facility (CBTF),
please go to upper left corner of your monitor and press
"Applications". In the drop down menu that appears, mouse over the
"Programming" submenu. This opens up another menu that shows the
different program editors available. Please click on the "RStudio"
menu item.
When RStudio opens, you will see red text indicating that CRAN cannot be reached. This is okay and is by design to meet the CBTF security model requirements. All packages required by STAT 385, STAT 430 DSPM, STAT 432, and CEE 202 have been pre-installed on the CBTF computer.
Please keep your work in an RMarkdown document. To create an RMarkdown document, press the “White Plus” on the green background in the upper left corner and go down to the “R Markdown…” entry.
This will open a window asking what kind of RMarkdown document you
would like. Type in the Title: field "CBTF Exam" and then press
okay.
From there, you should be ready to go! Please wait for the proctors to tell you when to being the exam. We wish you the best of luck and good ability on your exams and quizzes using R!
Below are some common errors appear from time to time when attempting to use R and RStudio in the CBTF.
Avoid trying to install packages. As was shown in the beginning, the package installation feature is disabled within the CBTF. Courses that use R in the CBTF have all the necessary components for their assessments.
If a required package is missing from a computer, please immediately alert a proctor by raising your hand.
To copy and paste inside the CBTF, please use the following keyboard shortcuts:
- Copy:
CNTRL+C - Paste:
CNTRL+V
The + means hold down both CNTRL and C together to copy text.
Alternatively, you can use file context menus Edit -> Copy and
Edit -> Paste.
Please avoid using the Insert key to paste results. The Insert key
changes the cursor from being a flashing vertical bar (|) to a
flashing horizontal bar (_).
Left denotes insert mode (`|`). Right denotes overtype mode (`_`).
If you accidentally press Insert, the over type mode can be exited by
pressing Insert again.
Pay close attention to where data is saved. Make sure to place the data file in the same folder that contains the RMarkdown or R Script to ensure it is able to be read in. Failure to do so may result in the data set not being found. These errors would look like:
Error in file(file, "rt") : cannot open the connection
In addition: Warning message:
In file(file, "rt") :
cannot open file 'bad/path/to/data.rds': No such file or directory
When downloading files from a question, the default save location on a CBTF computer is:
/home/<Your_NetID>/Downloads
Note: Both Firefox and Chrome web browsers will default to the above location. However, if saved from Firefox, then you will receive a prompt to select a save location for a file with the default location prefilled. Whereas when using Chrome, the file will be silently saved to the default location.
When saving an R script or RMarkdown file from RStudio, the default location that is saved to is:
/home/<Your_NetID>
Please replace <Your_NetID> in the above paths with your NetID not
surrounded by <>.
When writing more advanced code, RStudio may crash during its execution. The crash error will look like:
This indicates that there is a show-stopping bug in the code being executed. Try to either debug the code or start from scratch and slowly build it up.
The proctors inside the CBTF cannot provide debugging assistance.