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

Yoshiki Ohshima Yoshiki.Ohshima at acm.org
Thu Aug 4 20:10:17 UTC 2022

```Thank you!

I took the screenshot with SqueakJS but did not occur that I can share the

On Thu, Aug 4, 2022 at 12:46 PM Vanessa Freudenberg <vanessa at codefrau.net>
wrote:

> Found your project, and it works in SqueakJS:
>
>
> https://squeak.js.org/etoys/#fullscreen&document=http://www.squeakland.org/content/showcase/everyone/accounts/yoshiki/Sawtooth%20Wave.008.pr
>
> Vanessa
>
>
> On Thu, Aug 4, 2022 at 9:55 AM 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
>>
>>
>>
>

--
-- Yoshiki
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