Used it a lot as a replacement for matlab at the university. Nowadays, I just fire up ipython when I need some calculations. Then again my calculations now are nowhere near the complexity of what I did then. If I ever need to go back to the big matrices, I know where to find scipy/numpy.
I'm writing some GPU code that is called from Matlab. I don't have a Matlab licence, so I test everything using Octave (it has mex support). Works just fine.
This is consultancy work in geophysics. I'm writing code for a colleague to use (he does have a Matlab licence) who is working with a mining company.
Actually, if anyone is using this as a reference, I should add that it's not 100% identical. Octave doesn't support nested functions (it will interpret them as separate, but doesn't have any notion of closures, so if you reference a value in an outer scope it will fail). Also, at least one routine returns data in a slightly different format (listing files in a directory - the Octave approach is much simpler, and leads to cleaner code, but causes problems with inter-op). But moving a fairly large hacked-together (ie growing from exploratory data analysis) set of scripts from Matlab to Octave took less than an hour of testing and editing.
Yes, I work as a dev in the Neuroimaging field and Matlab and Octave are pretty entrenched. While I don't really use it for new development, I often have to used tools that depend on matlab.
I so wish SPM ran on octave.... It's not there yet but we've fixed a lot of octave bugs by throwing parts of SPM at it.
In robotics Matlab is pretty commonly used as a data analytics tool, and this gives me pretty much all of the basic functionality that I'd need.
Yeah. Doesn't everyone just whip out their HP 41CX?
I tried, no I really really tried hard (one hour of googleing is a long time in google time), but I can't. I have to use MatLab for control systems course I am taking. The problem is at college I submit my code as a matlab file and the control toolbox in octave is not syntax compatible with matlab control toolbox. So I guess octave lost to my university site licence.