OpenSUSE 12.1 seems to have dropped GNU Octave from its default package list; and at the time of writing, it is not available with the default repositories as well. However, it is available with the “science” repository for 12.1, along with all its dependencies:
To install, add the following URL as a new repository to YaST (YaST Control Center > Software > Software Repositories):
Accept the GPG Key when prompted. Now install octave with gnuplot using zypper as root:
SUSE-root> zypper in octave gnuplot
This will also install any other dependencies if not present in the system. When it is run the first time, this particular version of Octave (3.4.3) seems to get stuck at loading some startup commands, so invoking it from the desktop as a launcher may give the impression that it has hanged (the octave command prompt may not appear). If this problem is faced, run Octave the first time in verbose mode from prompt:
SUSE-user> octave --verbose
This will show where the application is getting stuck. It should show the command prompt after executing the batch of startup commands:
executing commands from /usr/share/octave/site/m/startup/octaverc ... done.
executing commands from /usr/share/octave/3.4.3/m/startup/octaverc ... done.
Once this comes, subsequent launches of the application will not need verbose mode explicitly.