Coding Challenge 161: Estimating π from Random Numbers with Euclid's Algorithm

🎬 Editing by Mathieu Blanchette

Links discussed in this video:

Other videos mentioned in this video:

Timestamps:
0:00 Happy Pi Day!
1:26 Explain! What does co-prime mean?
4:21 Explain! Euclid's Algorithm
8:40 Example! Finding the greatest common divisor.
9:55 Code! gcd() function with Euclid's Algorithm.
12:23 Code! Let's load the random digits.
14:39 Code! Let's use draw() for our loop.
16:13 Code! Co-prime or Co-factor?
17:44 Explain! How we are going to estimate π.
18:50 Code! Estimating π.
21:59 Code! Trying with digits of π.
22:54 Ideas! Thanks for watching!

#PiDay #PiDay2021

[anthonycannet]

It would take longer to run but instead of increasing index by 2, just increase it by one. Currently the program checks gcd(a, b) then gcd(c, d) and so on. Increasing by 1 would check every consecutive pair, so gcd(a, b) then gcd(b, c) then gcd(c, d) and so on. You get almost twice as many pairs of numbers which is one of the two things that affects how accurate this is. The other thing being how big your random numbers are.

Another way to improve the estimation would be checking every number against every other number but that would take much much longer to run...

[kabirbatra]

I'm in love with this editing style

[tompov]

If you choose substrings of 4 digits instead of 5 the estimation becomes 3.14159 🤯

[ncot_tech]

You're not the only one who gets modulus/modulo mixed up. When I teach it, I just call it "mod" and avoid the whole problem ;-)

[Mrjcowman]

The post-processing on this whole video is great XD love all the gags and running jokes

And what a fun program, too!

[grumpyparsnip]

Using the randomness of the digits of pi to estimate the digits of pi. That is beautiful.

[wpersona]

"The Best Video of the Coding Train Ever"

[gamesvrtech]

This morning the date on our clock showed us 3.14 and I immediately thought about you and your great videos.
Thanks for beeing who you are, wish you all the best!
Happy PiDay🍰🅿️ℹ️

[footballknight]

Daniel you can use the series 3 + 4/(2*3*4) - 4/(4*5*6) + 4/(6*7*8)... to estimate PI! I did it in p5.js and got amazing results!

[adsoyad]

I did this exact thing inspired by the exact same video a year ago!

[gouravchouhan]

Short function for GCD,

function GCD(a, b){
if(b == 1) return a;
return GCD(b, a%b);
}

[darthtorus]

i love all the new cute animations added to the videos

[jcponcemath]

The video production is getting just better and better. Thanks. Great finale 🤯

[xnick_uy]

I haven't visiting this channel for a while, and now I found a superb edition!! It was magnificent.

[CedLePingouin]

I'm a regular viewer, but I enjoyed this video even more. Love the animation at the beginning, the song, and the funny animated characters during the video. Great job :-)

[Operaatoors]

10:39 - just min and max functions. Or sort the array and then pick in order.
Although, this version is good as well :)

[fakenamerealguy]

Fwiw, when you said recursion I smiled happily

[samuelgunter]

I would cache the results of the gcd call to prevent having to calculate the same gcd multiple times. this sounds crazy because you probably won't get many times of having the same 5 digit number, but the chance of a cache hit increases as it gets down to fewer digits. you can also do this cache check after the reordering of a and b to make sure it hit both (384, 78) and (78, 384)

[cortiazz]

Yo, nice intro! I love the whole "world" that you built up to this channel

[ramkumars]

Hi Dan!!... i liked it!! especially the animations that you included in the video!!! plz keep those animations in the future videos as well!!.. Thanks a lot!