Opening
I leave the result of studying Fourier series in the last few days in a form of exploration. There are a lot of videos about Fourier series and its visualization. It would be great if you search them. (Of course, I'm not good at English so I couldn't understand them much.)
Overall, The following writings deal with visualization through JavaScript. But, exceptionally, in chapter two uses Web Audio API in order to reproduce an approximated waveform. So you can hear it. (It will be great if you have an microphone and you are in an environment you can let your voice out!)
In chapter one introduces basic content of Fourier series and Fourier coefficients, so it will be a good thing to see them.
I think it requires no knowledge of JavaScript that reading this writings. (Perhaps...)
But, if you have some programming experience, it will be easy to read code. But what is important in these writings is an mathematical approach, not programming things.
But you need to type some code in the console window in chapter two in order to interact with the writing, so let's practice a bit before here. (I was able to choose buttons to make the writing able to interact with you, but it is more fun to type code)
First, you can open the console window by pressing F12 in the keyboard.
Then a window like that will appear. Click the 'console' at the above menu. And, type the below to the console window.
Then a sentence will show up here
$exampleText.textContent = 'Hello Fourier series!';
This is surely a very interesting experience!
※ Some codes have // in their texts. It is just a mere comment, so you can ignore it. It does not affect the execution of code.
Anyway, all thing is done now. Let's depart in order to explore Fourier series.
Plus, in order to do fun things in chapter 3 and 4, you need to download Inkscape. Here is the link.