Any Octave users? What is this code snippet actually doing?

[David Rysdam]

On Sat, 06 Apr 2013 14:03:58 -0400, Bruce Labitt <bruce.labitt at myfairpoint.net> wrote:
> I'm trying to understand a chunk of 3D FDTD code that I downloaded from 
> the publisher of the book, "Computational Electrodynamics".  

I can't answer your question, but I may enjoy an elaboration of the
above. Years ago I started some simple-minded electrodynamic simulations
and gave up when it got hard. I wanted to simulate a "Farnsworth fusor"[1]
absent a means of actually building one.

[1] http://en.wikipedia.org/wiki/Farnsworth_fusor