Name: Coding Challenge #110.2: Recamán's Sequence - Part 2 (Audio)
Uploaded: 2020-03-28T18:58:48.000Z
Duration: 14 min 36 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

Do another video about the recommendation sequence in the previous video.

I did waas visualize it and you could see here.

I wrote to visualize the recommend number sequence as a continuous series of arcs.

Looks like they're circles, but they're actually connected.

Arc's gonna watch the previous video where I go and build this whole code.

But one of the things that that you can do also with number sequences besides visualize them is create an audio version of them.

And in fact, if you go back to your favorite website entirely in the entire world the online Encyclopedia of integer sequences you know, if I'm here on the recommends sequence page, I can click right here to listen, and it will give me a MIDI file Mini being a system for encoding music as numbers.

So if I can encode music as numbers and I have a number sequence that I could make that number sequence midi and then I can play it as music.

So this is what I want to try to dio and I'm going to attempt to do it with the P five Jess Sound library.

And I don't really know that Well, so we're doing a lot of looking up in the reference while I do this going to do with it oscillator to generate a sound and the envelope an envelope to kind of craft that sound essentially create my own synthesizer.

Should also mention that this video was pointed out to me from Dale.

Which is also visualizing sequence in a completely different way with colors and also making it so I hope after watching both of these, we will see a world full of mean.

Let's see a world full of visualizations and audio versions of numeric sequences.

Want him to keep the visualization going, and basically so I could start from scratch.

What I want to do is I want to play a note.

So let's see if I how how to best to do this.

So the first thing that I know that I need to do is I need to create a oscillator.

And oscillator is an object that will generate a tone.

And there are different kinds of oscillators, right?

It's basically a pure sound wave, and I can have a sine wave or a triangle wave.

And I believe I have a video about P five oscillators that will go into that perhaps a bit more.

What I'm gonna do is I'm just gonna take this code exactly as is, and I'm gonna paste it into set up you're coding challenge copy paste from examples.

And then I'm going to create make that a global variable.

And I'm goingto discover what interesting error I will have now.

So P five oscillator is not a constructor.

Because I don't actually use the sound library that often.

So I'm gonna go and add reference in my html file to the p five sound library.

So hopefully that's gonna clear that error up.

So let's go to the sketch and why do we not hear anything?

Let's set the amplitude toe one and which is 100% volume hit.

So I have this click back here to stop the sound for a second.

I have this number sequence that's going up.

They're 0136 to 7 13 20 What if I just took each number and assigned it off and took the number in the sequence and made it a frequency?

So, for example, as I'm stepping through, I could say oscillator frequency Index right index is actually the number of that that's currently part of the sequence.

So if I do this and go back to here and click on this, I don't hear anything.

Do you hear something you might have to have?

Eventually, I think I'll start Here is something.

So here's the thing there is a range off frequencies frequency as, ah being a measurement of how many cycles of a wave per second.

So now we can start to hear it e like that.

Okay, so for a while, we didn't hear any notes.

And all this time we started to hear something.

So you don't think it's much too arbitrary to just set a the number from zero to whatever as the frequency?

There is a specific audible range of frequencies that we can hear.

And so and there also are formulas for converting from many notes to frequency and back and forth.

Clearly, there's something going on in the hallway was something I could do about it.

Right now, it is gonna be in this video forever, but and so I pretty sure that p five has a like MIDI to frequency or to note or something functions somewhere.

I'm gonna go to this Wikipedia page, which I have loaded up here called piano key frequencies.

And if you look at this, this formula here, I want to use this basically if we number all the keys on the piano from the very bottom key to the top key.

I can't remember how many keys are on a piano.

We can actually find the frequency of any key end through this formula.

Sure, we could think about this in interesting ways, but I'm just gonna go and use this formula.

I'm going to say so if the if the recommendation numbers all these numbers and I'm just going to do from 0 to 88 like, I'm not gonna let it go forever.

If I consider each one needs to be a key on the piano, then we should be able to play the music.

So I want to say the, uh the frequency is Go back to this formula, uh, to to the n minus 49.

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Coding Challenge #110.2: Recamán's Sequence - Part 2 (Audio)

weird

insane

grab

recommend