## [squeak-dev] [offtopic] Fourier transform

karl ramberg karlramberg at gmail.com
Thu Aug 4 20:26:40 UTC 2022

```[image: bild.png]
Fun stuff :-D
Here is a version of a spirograph I made in the Etoys image a few years ago.
I had the trails form in the play field move so I could make a cool graph

Best,
Karl

On Thu, Aug 4, 2022 at 6:55 PM Yoshiki Ohshima <Yoshiki.Ohshima at acm.org>
wrote:

> It's fun indeed.
>
> I remember making some Etoys to draw some regular waveforms...
>
> [image: e.jpg]
>
>
> On Thu, Aug 4, 2022 at 7:58 AM Vanessa Freudenberg <vanessa at codefrau.net>
> wrote:
>
>> On Thu, Aug 4, 2022 at 01:15 Stéphane Rollandin <lecteur at zogotounga.net>
>> wrote:
>>
>>>
>>> > I'm unable to think algebraically very effectively but can
>>> > think visually (for example I didn't understand the fourier transform
>>> > algebraically (the double integral formulation), but understand it
>>> > perfectly well as an infinite set of infinite integrals of the
>>> products
>>> > of a sine wave with an arbitrary waveform (itself composed of sine
>>> > waves)).
>>>
>>> As a visual person myself, Fourier transform did only really click with
>>> me intuitively when I saw it related to epicycles. See Mathologer's
>>> video here:
>>>
>>>
>>>
>>>  Stef
>>
>>
>> Thank you for that video! Really enjoyable – I knew the epicyclic
>> explanation for how Fourier synthesis can generate a curve, but never
>> understood Fourier analysis, how to find the factors for a given curve. I
>> had a light bulb moment in the last part of the video where all the
>> integrals in the infinite sum become zero except for one particular term.
>> Beautiful!
>>
>> Vanessa
>>
>>>
>>
>
> --
> -- Yoshiki
>
>
>
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```