It doesn't matter if MacOS is advertised as UNIX or not. Technically, it is UNIX.
The practical issue is that you are using GNU programs written with the Linux/GNU operating system in mind. Of course this experience is sub-par on the Mac, because neither the Octave- nor the Gnuplot-developers see Mac OS X as their primary market.
The practical issue is that you are using GNU programs written with the Linux/GNU operating system in mind. Of course this experience is sub-par on the Mac, because neither the Octave- nor the Gnuplot-developers see Mac OS X as their primary market.