Octave 2.1.59 is the latest version of Octave. Please notice this is not considered to be stable (even though it does not look unstable either). Together with Octave 2.1.58, mentioned in bug 62982, it should be kept with a ~x86 (and ~ppc and so on) keyword. It's also about time octave-2.1.57 is marked stable, together with its correponding octave-forge version, 2004-07-07! The latter would need an ebuild too...
Created attachment 40273 [details] Ebuild for octave-2.1.59
2.1.64 is now in portage, close this bug.
Superseded by ebuild for 2.1.64, closing bug
Closing