This file has been on the FEX for a while without much attention, so let me take a look.
It is a pretty specialized area, where I am not an expert, so I would not rate this tool on its intended usage. (Some of the pieces are pretty generic, so the eigen.m code is something I could talk about. It was well written.)
However, I can talk about the overall tool itself, in terms of the code. Every part I looked at had excellent documentation. There were internal comments, H1 lines, all things I like to see. Where appropriate, I found matrix operations instead of loops, etc.
I have proposed to come up with a Python implementation of the HHT under the Google Summer of Code programme. But I'm worried about the patented status of the HHT.
I see many implementations of the HHT that are freely available, and a lot of research papers are based on HHT too. If the interest is purely academic and non-commercial, can HHT be used freely?
Please help me out.