The homepage of Chris Lomont
Ever since third grade I have been fascinated with computers, electronics,
and robots. Most of what I do professionally and for hobbies revolve around
this. My most time consuming hobby is programming things for fun, research,
and profit. See my computer page for more details.
I love solving puzzles of many kinds: sliding block, mathematical,
research, word, chess, brain benders, etc. I once joined Mensa, thinking it
would get me more puzzles and puzzle people, but after it did not, I let my
A Simple Fast Fourier Transform
This article (600kb PDF) presents
a free, simple, fast Fast Fourier Transform
in C#. It derives the code and explains the FFT in detail. It also presents a real to complex FFT
useful for many engineering tasks which has the advantage
of being twice as fast and uses half the resources as a traditional FFT. Source code is available in
The Hidden Subgroup Problem - Review and Open Problems
An overview of quantum computing and in particular the Hidden
Subgroup Problem (HSP) is presented from a mathematical viewpoint. Detailed
proofs are supplied for many important results and notation
is unified, making it easier to absorb the background necessary to begin
research on the HSP. Some errors in previous proofs are corrected. Proofs are provided which give
very concrete algorithms and bounds for the finite abelian case with little outside
references, and future directions are provided for the nonabelian case.
This summary is current as of October 2004. 83 pages.
NEW! Check out our site to sell cubes at www.hypnocube.com!
The construction of a LED cube is chronicled (Main page, Part I, Part II, Part III, Part IV, New Videos, Old
Videos). Currently we sell commercial 4x4x4 cubes and kits at www.hypnocube.com, and are still working on the larger
8x8x8. The final goal is a 4096+ color 8x8x8 cube that plays visualizations, sound animations, and
user defined art, and is a standalone unit that can be placed anywhere in the house. It will likely
support a wi-fi web interface for easy user scripting of visualizations and modifications.
This is a pseudo-traditional plasma demo showing nice animated layering effects. If you are familiar
with the standard plasma effect from the demoscene, you will like this version. There are three sets
concentric circles, warped as they wobble, and then XOR'ed in bitplanes to get the nice coloring.
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