GNU Octave released version 8.4.0 this Sunday. Here’s how to install it in Ubuntu 20.04, Ubuntu 22.04, and Ubuntu 23.10 via PPA.

GNU Octave, a high-level interpreted language for numerical computations, release new 8.4.0 few days ago. The release came with mainly bug-fixes and improvements.

The official announcement is not ready yet. But, according to the in-app release note dialog, the changes include:

• mkoctfile: Skip parsing for less flags.
• Fix getting number of non-zero elements in SuiteSparse matrices.
• delaunayn.m: Avoid erroneous simplex removal for integer inputs
• delaunayn: Add precision loss warning for large int inputs.
• delaunayn: Also warn for negative integers with large magnitude
• Correctly load all-zero sparse matrices from text files.
• Allocate correct storage for interleaved complex mxArray objects
• mkoctfile: Prefer parsing over passing on argument after unknown argument
• fft: Avoid segmentation fault with ND-arrays.
• fft: Avoid overwriting input for inplace operations.
• intersect.m: Correct third output with “stable” flag.
• Avoid use-after-free issue in parser.
• betainc.m: Improve integer input logic and validation.
• webread: Apply timeout also for initial connection.

There are as well a few build system changes and documentation updates. For more, keep an eye on the news page.

How to Install Octave 8.4.0 in Ubuntu:

GNU Octave does not provide official packages for Ubuntu, since the official PPA has been discontinued for very long time.

To get it in your Ubuntu Linux, there are so far 2 choices: Flatpak package and Ubuntu PPA.

Option 1: Flatpak

Flatpak is an universal package format for Linux. It can install in most Linux system, however run in sandbox.

To install Octave as Flatpak in Ubuntu, simply press Ctrl+Alt+T on keyboard to open terminal. Then, run the 2 commands below one by one:

• First, make sure Flatpak daemon is installed by running command:

  sudo apt install flatpak

• Then, install Octave as Flatpak via command:

  flatpak install https://dl.flathub.org/repo/appstream/org.octave.Octave.flatpakref

Tips: first time installing an app as Flatpak, needs a log out and back in to make app icon visible. And, it may have many downloads for run-time libraries.

Option 2: Ubuntu PPA

There are also few unofficial Ubuntu PPA contains the most recent Octave packages. And, I have made this PPA for Ubuntu 20.04, Ubuntu 22.04, Ubuntu 23.04 & 23.10 with both x86_64 and arm64/armhf support.

1. First, press Ctrl+Alt+T on keyboard to open terminal. When it opens, run command to add the PPA:

sudo add-apt-repository ppa:ubuntuhandbook1/octave

Type user password (no asterisk feedback) when it asks and hit Enter to continue.

2. After adding PPA, Linux Mint users need to manually refresh system package cache, though it’s done automatically in Ubuntu.

sudo apt update

3. Finally, either run command in terminal to install the software package:

sudo apt install octave

Or, use “Software Updater” (Update Manager) to install updates if an old version was installed on your system.

Uninstall:

For choice, you can either downgrade Octave package to the stock version in system repository by purging the Ubuntu PPA. To do so, open terminal (Ctrl+Alt+T) and run command:

sudo apt install ppa-purge && sudo ppa-purge ppa:ubuntuhandbook1/octave

Or, remove Octave by running command in terminal:

sudo apt remove --autoremove octave octave-common

And remove the Ubuntu PPA by running command:

sudo add-apt-repository --remove ppa:ubuntuhandbook1/octave

If you installed Octave via Flatpak package, run the command below instead to remove it:

flatpak uninstall --delete-data org.octave.Octave

Also, run flatpak uninstall --unused to remove useless run-time libraries to free up some disk space.