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

[Bruce Labitt]

I'm trying to understand a chunk of 3D FDTD code that I downloaded from 
the publisher of the book, "Computational Electrodynamics".  It is in 
matlab, so I tried to run it in Octave.  Something is not quite right, 
so it doesn't execute.  That doesn't matter to me right now.  The piece 
of code is:

//start snippet
%   x-varying material properties
delbc=upml*delta;
sigmam=-log(rmax)*(orderbc+1.0)/(2.0*eta*delbc);
sigfactor=sigmam/(delta*(delbc^orderbc)*(orderbc+1.0));
kmax=1;
kfactor=(kmax-1.0)/delta/(orderbc+1.0)/delbc^orderbc;
//end snippet

It would seem to me that kfactor is always zero, since kmax is set to 1 
in the line above.  That probably is not the intent, I think. kfactor 
does not seem to be updated later in the code.

Is this just a bug?  Or what does the last line do?  The author of the 
code is a long graduated PhD student from UWisc.  Just contact UW?

URL of actual code: 
http://www.artechhouse.com/static/downloads/fdtd3D_UPML.zip

It doesn't matter if it executes in octave.  (It would be nice, though - 
it currently runs, plots a little, then seg faults)

octave:1> fdtd3D_UPML
error: base_graphics_object::get_properties: invalid graphics object
panic: Segmentation fault -- stopping myself...
attempting to save variables to `octave-core'...
save to `octave-core' complete
Segmentation fault

I tested the code in Matlab, and it executes.  Can't really say if the 
code is doing everything right, but it runs and vaguely does things sort 
of ok. The simulation is kind of coarse, but one can see an electric 
field starting to radiate from a dipole.

I'm porting it to python/scipy and maybe later to pycuda, once I get it 
working.  Then maybe I can do some cool stuff with it.

Thanks in Advance
-Bruce


-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.gnhlug.org/mailman/private/gnhlug-discuss/attachments/20130406/b6a64cdb/attachment.html