

The Fast Fourier Transform - signa11
http://jeremykun.wordpress.com/2012/07/18/the-fast-fourier-transform/

======
Hitchhiker
" As noted by his former pupil and collaborator André Deprit, Lemaître was one
of the inventors of the modern Fast Fourier Transform technique.

Lemaître was well ahead on his time regarding machine computing. As early as
the thirties at MIT, he used the machine perfected by Bush to solve the
Störmer problem. "

source : <http://www.uclouvain.be/en-316446.html>

------
ctchocula
Seems like a great blog. I'm trying to get through The Road to Reality by
Roger Penrose that's supposedly capable of giving a layman an idea of the math
and physics behind modern physics including string theory, but I'm finding
Jeremy Kun's treatment of some of the same mathematical concepts using
animation and colloquial language to be easier to understand.

------
rodh
Wow. I hadn't come accross this blog before. It has a fantastic wealth of
content, all relevant to my interests. Very impressed.

~~~
textminer
Love his tutorials. Motivates PCA by walking trough a creepy eigenface
decomposition, and solves a political prediction problem with a ID3
implementation of a decision tree. I actually used the latter initial code
scrap for writing an entire damn random forest implementation!

Really looking forward to his future discussion of computational topology and
persistent homologies.

------
napoleond
Excellent article! In case anyone has use for it, the other day I wrote a
quick little javascript implementation of the FFT for inclusion in sjkaliski's
numbers.js[0]. It hasn't been merged in yet, but my implementation[1] is tiny
and (hopefully) easy to read. (complex.js and dsp.js work fine on their own,
without the rest of numbers.js)

[0] <https://github.com/sjkaliski/numbers.js>

[1]
[https://github.com/napoleond/numbers.js/blob/master/lib/numb...](https://github.com/napoleond/numbers.js/blob/master/lib/numbers/dsp.js)

------
OldSchool
Great content! Nice mix of math, backstory and practical examples along the
way to keep the reader engaged.

I was a little concerned that the Python cmath library might be written in
Python but from what I can tell, it's native-code from C.

~~~
jamesgeck0
Yep! In general, any Python library prefixed with a C will be native.

------
agentq
For anyone who _doesn't_ want to roll their own FFT, take a look at this
excellent pure C implementation: <http://www.fftw.org/>

~~~
j2kun
This is a parallel agorithm...

------
guan
When you present the Fourier transform as frequency spectrum, what are you
actually plotting? Magnitude? Real part?

