I've installed Octave for Android on my Nexus 7 running Adroid 5.1.1. I can even run a trivial plot from a command I typed by hand in the terminal emulator.
Octave comes up saying my home directory can be found at /storage/emulated/0/GNUOctave/home. I mount my Nexus 7 on my windows machine as a media device where the only volume that shows up is called "Internal storage" I look around and search and can't find even "emulated" in internal storage, and searching on "octave" gets me a folder with a patch in it but no closer to my home folder.
pwd in the terminal emulator only shows me "/home"
Looking at file system in ES Explorer on the Nexus 7, I can find my Octave home. It is in a GNUOctave folder which is obviously at the top level of "Internal storage" but is the only folder ES Explorer shows which does NOT show up in Explorer on my PC!
I feel stupid about this, but it did cost me an hour and I am not actually stupid.
I powered down the Nexus 7 and restarted it. When it came back up, the GNUOctave folder showed up in explorer on my windows laptop and my problem is solved.