Question: I want to install Octave on my Ubuntu LTS with `apt-get`. The problem is that the official repositories list only Octave 3.0 and Octave 3.2, whereas the latest Octave is Octave 3.6.

How do I update the repositories of apt-get to get Octave 3.6?

Answer: 
The answer is quite simple. Go to the [Octave downloads website](http://ftp.gnu.org/gnu/octave/) and find the latest release of GNU Octave and download the .tar.gz file of it.

After this copy and paste the following terminal (CTRL+ALT+T) commands:

```
sudo apt-get build-dep octave
cd ~/Downloads
sudo mv octave-x.x.x.tar.gz ~
cd ~
tar xvf octave-x.x.x.tar.gz
cd octave-x.x.x
./configure
make
sudo make install

```

Where the 'x.x.x' refers to the version of GNU Octave you'd like to install, such as 3.6.3.
Latest ppa is ppa:octave/stable.

<https://launchpad.net/~octave/+archive/ubuntu/stable>

This ppa is maitained by the "GNU Octave" team and has version 3.8.1 available for lucid and precise.