Mode expansion

[HomerReid]

Initial skeleton framework for mode-decomposition feature.

[HomerReid]

I've mostly ported the waveguide-taper calculation to python. The python code is doc/docs/ModeExpansionFiles/wvg-taper.py. It's a port of libmeepgeom/wvg-taper.cpp.

There are a couple of things that aren't working in python yet. I'll try to fix those over the next days. I might need some help with typemaps, etc.

Here is the latest version of the documentation / tutorial. I need to fill in some plots and code snippets.
ModeExpansionDocumentation.pdf

Here is the log-log plot of power loss due to intermodal scattering vs. taper length for taper functions of continuity class C^p for p=0,1. To the extent that I represent them as power laws, they are both roughly going like L^{-2} (with L the taper length). I think the correct answer is that the power-law exponents are supposed to differ more clearly, by a full unit of 1, so this is maybe a little fishy.

[HomerReid]

[HomerReid]

ModeExpansionDocumentation.pdf