I'm having a problem loading packages with Octave. I'm brand new to Ubuntu and Linux in general (just installed yesterday!), so I'm sort of lost on what to do.

I've installed Octave 3.4.0 from one of those tar.gz files (after looking up loads of help on the Internet) because the Ubuntu Software Center only has 3.2.4. Afterward, I installed QtOctave from the Ubuntu Software Center.

I subsequently tried to install packages (notably Controls and Signals) using QtOctave's package installation feature. If I try to use a command from one of those packages, like "help tf2sos," I get an error saying the command doesn't exist. Is this because I haven't installed things correctly? Maybe I don't have some "dependencies" I keep reading about? Maybe that version of QtOctave isn't compatible with Octave 3.4.0? I'm completely lost on where to turn.

Any help will be GREATLY appreciated. I'd like to use Octave instead of MATLAB, but I may have no choice at this point.