Well trying to get (finally!) through the CS223 class on Coursera and actually do the homework, etc. One of the nice things is that Coursera let's you run the entire course offline on your phone. But one of the big issues is that they only let you run a version of MATLAB on the server, so you can't be truly disconnected.
The solution is to try Madona, which is an Octave implementation on IOS. That makes some sense given how powerful phones (and iPad Pros!) are these days. The only real limitation here is that you do have to run sandbox.show() to actually see the plots and I don't know if it will run all the exercises, but good to try.
The other thing is that on a Mac, they require you to use Octave 3.8 for which there is a direct DMG download, but when you do a brew install octave you actually get version. The course wants you to do a direct install, but I actually like doing the Home-brew. There are few things to know about that the main one is that you want to use the native gnuplot rather than qt, so you need to modify your ~/.octaverc to add. This doesn't seem to be needed anymore as an aside, so don't do this, the Octave 5 that downloads seems to do this by default.

setenv('GNUTERM', 'qt')
graphics_toolkit("gnuplot")

The bigger issue is getting the older Octave, with brew you can look for older versions which are denoted by the syntax package@version but there is no octave@3 available.

## Making Vim work with Octave

There is a edit command in Octave, so you can just type that in, but you need to create an .octaverc to do this. For Version 4 and above, you use the EDITOR() operator syntax and for earlier versions, the edit editor command.

edit mode sync
edit home .
# syntax for earlier version
# edit editor 'vi >/dev/tty 2>&1 </dev/tty %s'
EDITOR('vi >/dev/tty 2>&1 </dev/tty %s')