FFT : Java Glossary

FFT

FFT (Fast Fourier Transform). Analysing a wave into its equivalent superimposed sine waves of various frequencies. You can think of it as separating out a tone from its overtones mathematically. Joseph Fourier (born: 1768-03-21 died: 1830-05-16 at age: 62) was a French mathematician who proved this was always possible (It turned out later, only under non-pathological conditions). Originally, to analyse sound in real time required special purpose hardware, such that we used at the Human Dolphin Foundation back in 1979 to analyse dolphin sounds. Today it can be done routinely with off-the-shelf desktop computers.

Modems have special purpose hardware that do a form of FFT to sort out the many-noted chords the modems use to talk to each other. By sending chords for extended periods of time helps mathematically average out the static noise.

Back in 1824 Fourier discovered the greenhouse effect (when Marx was still only 6 years old). Svante Arrhenius, the great Swedish chemist published his calculations in 1896 about how atmospheric CO₂ concentrations control the average global temperature, and how certain amount of CO₂ was needed to prevent an ice age.

Apache Commons FFT
Colt Discrete FFTs
FFTW: FFT library in C
GSL: Gnu Scientific Library can compute FFTs
Intel’s high speed math library
Joseph Fourier
JTransforms: FFT in Java
mathematics of various types of Fourier Transforms
Michael Flanagan’FFTs: in Java
modem
Name That Tune Student Project
Rogue Wave IMSL: FFT in Java
Wikipedia on FFTs

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