Mastering The Fourier Transform in One Day
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Mastering The Fourier Transform in One Day
1–6 of 6 posts
Re: Mastering The Fourier Transform in One Day
#2Ahhrrr... I looked at the page and though "Wow, I will finally do it... one day" and decided to add it to my Delicious account, only to realize it was already there.
And then it came to me: it was probably posted on HN few months ago, I decided to read it "later" and created that Delicious link :)
Re: Mastering The Fourier Transform in One Day
#3Yeah...I wouldn't call that mastering. It is a good overview nonetheless.
Re: Mastering The Fourier Transform in One Day
#4 float wr, wi, arg, *p1, *p2, temp;
float tr, ti, ur, ui, *p1r, *p1i, *p2r, *p2i;
long i, bitm, j, le, le2, k, logN;
Especially heinous is when, like this snippet, the variables are not explained anywhere. I dislike de-obfuscating code to understand an algorithm, especially when posted on a page which claims to help you understand it (this is the FFT, not the FT, but still. They might as well have shown LZW/BZ2, would you be able to tell the difference?).
Re: Mastering The Fourier Transform in One Day
#5mistake #1 when trying to understand or explain the Fourier Transform is to discuss the breakdown of f(t) into sine/cosine components. it's much easier to understand in terms of the original e^(i * w * t) waveforms, and the effects of integrating [-inf,inf]integ[f(t) * e^(-i * W * t)] for any given W. there's a nice visualization of this that involves considering the "helical" e^(i * w * t) waveforms and the twist that e^(-i * W * t) applies to these. bla bla bla.
Re: Mastering The Fourier Transform in One Day
#6Ahhrrr... I looked at the page and though "Wow, I will finally do it... one day" and decided to add it to my Delicious account, only to realize it was already there. And then it came to me: it was probably posted on HN few months ago, I decided to read it "later" and created that Delicious link :)
Yep, it was: