Access two versions (or more !) of R within RStudio

This method is suited for computer running under the Linux Ubuntu OS.

Goal

For various reasons, we want to easily switch between two (or more!) version of the R language with RStudio.

From my side, I have a specific setup of R packages installed within a Singularity environment. But, I fail to access the version of R within this environment, using RStudio. So, I installed everything locally and ask RStudio to open the specific version of R.

Method

The method consists in:

locate the path to R versions of interest
define alias to open RStudio using each of these versions
define desktop shortcuts to open RStudio in one click

Locate or install the R versions of interest

First, locate the folders where are installed the R versions of interest. For me, I have:

Version	Folder
3.6.3	`/usr/local/src/R-3.6.3`
4.2.2	`/usr/local/src/R-4.2.2`

Exemple to install R version 3.6.3:

Download the archive associated with the version of interest there: https://cran.r-project.org/src/base/ (eg. R-3.6.3.tar.gz)

version="3.6.3"

wget -O R-${version}.tar.gz https://cran.r-project.org/src/base/R-${version:0:1}/R-${version}.tar.gz

Decompress the archive in the final folder.

# Move the archive in the final folder
sudo mv R-${version}.tar.gz /usr/local/src/

# Decompress the archive
cd /usr/local/src/
sudo tar -zxvf R-${version}.tar.gz

# Remove the archive
sudo rm -f R-${version}.tar.gz

# Change directory to the uncompress archive
cd R-${version}

Install R.

sudo ./configure 
sudo make
sudo make install

Check the installed version.

R --version

The default R version used by RStudio is accessible by the which R command. It can be /usr/bin/R, which is a shortcut for the last version installed. If you installed first R 4.2.2 and then R 3.6.3, /usr/bin/R --version will show the 3.6.3 version.

Note: Within RStudio, another R version can be forced by setting the RSTUDIO_WHICH_R variable in the ~/.Renviron (or ~/.profile or ~/.bashrc) file. For instance:

RSTUDIO_WHICH_R=/usr/local/src/R-4.2.2/bin/R

Define aliases

In the ~/.bashrc file, create as many aliases as you have R versions of interest.

alias r363="export RSTUDIO_WHICH_R='/usr/local/src/R-3.6.3/bin/R' rstudio"
alias r422="export RSTUDIO_WHICH_R='/usr/local/src/R-4.2.2/bin/R' rstudio"

Note: The above commands work for Ubuntu 24.04. However, to Ubuntu 20.04, a ; should be added:

alias r363="export RSTUDIO_WHICH_R='/usr/local/src/R-3.6.3/bin/R' ; rstudio"
alias r422="export RSTUDIO_WHICH_R='/usr/local/src/R-4.2.2/bin/R' ; rstudio"

To consider the changes, source the ~/.bashrc file:

source ~/.bashrc

You should now be able to open RStudio with R 3.6.3 (or R 4.2.2) by running the r363 (or r422) alias command in the terminal.

Note: Using the ~/.profile file to define an alias was not working on my computer, running under Ubuntu 20.04.

Define shortcuts

To avoid opening the terminal and typing 4 characters to open RStudio, we can define shortcuts ! The shortcut will be represented as a logo, pinned to the dashboard. For this, many tutorials exist. I followed the one from Rich Hewlett.

Create a .desktop file, for instance called rstudio_with_r363.desktop, containing:

[Desktop Entry]
Type=Application
Terminal=false
Name=RStudio R3.6.3
Icon=/path/to/a/beautiful/rstudio_pink.png
Exec=bash -c 'exec bash -i <<< "r363" '
Categories=Application;

Details:

Terminal=false to not open the terminal in background
Name is the hover text when you pass the cursor above the icon
Icon corresponds to the path to the icon
Exec is a command behind the shortcut. I found it on Stackoverflow
Do not forget the ; in the end

You may have as many .desktop files as you have R versions of interest.

To add the shortcuts in the dashboard from Ubuntu, save the .desktop files in the ~/.local/share/applications folder.

Then, pin the shortcut to the dashboard:

find the shortcut using its Name, in the Ubuntu Menu
right click to ‘Pin to Dash’

No need to restart the computer: everything should be well recognized !

Resources: