View source for Installing Octave (with the GUI) from source on Ubuntu

As of November 2013, to get the GUI in octave, you need to build from source.  Here is roughly to do it.  You will need around six GB space on your hard drive to build octave from source.
* Install build-essential, mercurial, libqscintilla2-dev, qttools5-dev and the octave dependencies.
 $ sudo apt-get install mercurial build-essential libqscintilla2-dev qttools5-dev
 $ sudo apt-get build-dep octave
* Follow the instructions on the [http://www.gnu.org/software/octave/get-involved.html octave site] to use mercurial to clone the source to your hard drive.
 $ hg clone http://www.octave.org/hg/octave
 $ cd octave  ## Connect to the octave directory
 $ hg -v pull ## -v means "verbose", to get more diagnostic output
 $ hg -v update  ## This gets the latest updates.
* Build with these commands:
 $ ./bootstrap
 $ ./configure
 $ make -j2  # Leave the -j2 off if you don't have a two core processor or if you have four you can use -j4
* The build takes a while.  You may need to install some other packages if the ./configure tells you that you need them.