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1 Nov 2024 19:14:54 EDT (-0400)
  Understanding Fourier transform (Message 1 to 2 of 2)  
From: Darren New
Subject: Understanding Fourier transform
Date: 17 May 2011 12:39:20
Message: <4dd2a4b8$1@news.povray.org>
http://altdevblogaday.org/2011/05/17/understanding-the-fourier-transform/

That makes sense.

The way I had it explained to me what the transform does is that you take 
the polygon described as (x,y) pairs, and what the transform gives you back 
is the a_n in the a_0*x^0 + a_1*x^1 + a_2*x^2 = 0 formula. That's why I 
could never figure out how it was picking out frequencies and such.

-- 
Darren New, San Diego CA, USA (PST)
   "Coding without comments is like
    driving without turn signals."


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From: Orchid XP v8
Subject: Re: Understanding Fourier transform
Date: 17 May 2011 14:57:27
Message: <4dd2c517$1@news.povray.org>
On 17/05/2011 05:39 PM, Darren New wrote:
> http://altdevblogaday.org/2011/05/17/understanding-the-fourier-transform/
>
> That makes sense.

Yeah, that's the way I'd visualise it too.

The way I saw the formula written down is that you take the input wave, 
multiply it by different sine and cosine waves, and average. Thinking 
about this, I figured that if you have an osciliscope where the 
displacement plane rotates instead of translating, you'd get flower 
patterns that are off-center only if the frequency you're testing for is 
present.

...which appears to be what this guy is saying.

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*


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