How Some Formulas for π Are Faster Than Others

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  • เผยแพร่เมื่อ 26 ธ.ค. 2024

ความคิดเห็น • 44

  • @dibeos
    @dibeos  วันที่ผ่านมา +1

    PDF link if you want a more detailed explanation:
    www.dropbox.com/t/6YDaQi7FvHrFt4YU

    • @renengan25
      @renengan25 23 ชั่วโมงที่ผ่านมา +2

      Buen video 👍🏻

  • @anderskallberg7969
    @anderskallberg7969 20 ชั่วโมงที่ผ่านมา +23

    But you didn't answer why some formulas are faster at converging, just that some are faster

    • @dibeos
      @dibeos  19 ชั่วโมงที่ผ่านมา +6

      @@anderskallberg7969 well, we did show exactly how some are faster. The reason is because the terms you choose at each iteration (after multiplied by the previous one) produces an error (last formula of the video) that is less than another formula’s error

    • @kjv35
      @kjv35 15 ชั่วโมงที่ผ่านมา +6

      came here to say this. Shame that the video creators acknowledged it but gave you a silly answer. I was hoping for some explanation as to WHY the error is larger for the even/odd fraction series, not just that it is. I was really hoping that you'd use arctan(x), Taylor expand it around 1, and discuss WHY it converges at the speed that it does. Really could have taken this video in a direction that addresses the title. I admittedly haven't read the linked PDF, but I don't think I'll find what I want there based on what they said in the video.

    • @dibeos
      @dibeos  15 ชั่วโมงที่ผ่านมา +3

      @ well, I’m sorry that your expectations were not met. We really tried and thought it was the answer you are asking for. Next time we will be more precise

    • @kjv35
      @kjv35 15 ชั่วโมงที่ผ่านมา +3

      @@dibeos thanks for your response. I still think it was a decent video, just a bit of a misleading title. Still, it's great to see you are creating educational content. Please keep up the good work!

    • @dibeos
      @dibeos  15 ชั่วโมงที่ผ่านมา +1

      @ thanks, well at least now we know something you guys actually want so we can make a video on that 😅

  • @Vovik-fz4tx
    @Vovik-fz4tx วันที่ผ่านมา +10

    but second formula doesn't use square root computations, which have higher computational costs. So, in practical applications, we should compare amount of basic arithmetic operations (which can be performed by the processor)

    • @dibeos
      @dibeos  วันที่ผ่านมา +4

      @@Vovik-fz4tx Hm… yeah, good point. It’s a balance between operation cost and convergence speed

  • @someguy-k2h
    @someguy-k2h วันที่ผ่านมา +6

    That was fun. Are there other approximations that are even more efficient?
    What I would love to see is the thought process behind discovering these infinite series. Were they intending to find this? Were they just messing around and happened to notice the usefulness? Is there a best process or even a formula for finding these kinds of approximations? What do these approximations tell us about pi?

    • @dibeos
      @dibeos  วันที่ผ่านมา +4

      @@someguy-k2h The most efficient formula for approximating π is probably the Chudnovsky formula, but I’m not really sure. Historically, the first formula was discovered using nested radicals when exploring infinite series and geometric relationships in polygons inscribed in circles. The second formula was derived from insights in calculus and infinite series, starting with integrals for sine functions and their relationships. We have detailed proofs in the PDF link. If you have a good understanding of Calculus 1, it should be enough to study them. But yeah, both were methodical: Viete (first formula) worked from geometric principles, while Wallis looked for patterns in integrals. They didn’t directly aim for π but sort of “stumbled” upon it

    • @someguy-k2h
      @someguy-k2h 15 ชั่วโมงที่ผ่านมา +1

      @@dibeos Thank you so much for replying, and quickly. I know the Chudnovsky algorithm, from the Chudnovsky brothers. It's based on the famous Ramanujan-Sato series. I can easily see how a nested sum of increasing polygons can get you to π, but it's very interesting to me that this number which is used to describe the curvature of space-time pops up in so many strange places. I will read the PDF. Thank you for the response and the detailed content. You guys got my subscription.

    • @dibeos
      @dibeos  4 ชั่วโมงที่ผ่านมา +1

      @ thanks for the new videos ideas haha

  • @DadundddaD
    @DadundddaD 3 ชั่วโมงที่ผ่านมา +2

    Somebody used three dots. Other mathematicians: woah! what an invention!

    • @dibeos
      @dibeos  3 ชั่วโมงที่ผ่านมา

      @DadundddaD 😂😂😂 yeah, it was exactly how I imagined it

  • @bradzoltick6465
    @bradzoltick6465 11 ชั่วโมงที่ผ่านมา +1

    I loved it. Thanks for making these videos.

  • @ssdegfteghytr166
    @ssdegfteghytr166 12 ชั่วโมงที่ผ่านมา +2

    Interesting video that deserves more views

    • @dibeos
      @dibeos  4 ชั่วโมงที่ผ่านมา

      @@ssdegfteghytr166 thanks!!! Please let us know what kind of videos you’d like to see in the channel

  • @DaedalusCommunity
    @DaedalusCommunity 12 ชั่วโมงที่ผ่านมา +1

    Nice video! Loved the explanation and animations.
    I have just one objection, I think the title is a bit misleading. In the video, you only compare the convergence speed of the two algorithms empirically, by showing that one of them can achieve a certain precision faster than the other one. You did not quite go into **why** it is that one is faster than the other, you simply performed an experiment that shows that, indeed, one does converge at a faster rate. Showing "why" one algorithm converges faster than another would involve providing a proof, or at least an intuition, of why one iteration of the better algorithm is able to improve an intermediate solution more than one iteration of the worse algorithm would, or something along these lines.
    I suppose a more accurate title would be "Some Formulas for π Are Faster Than Others", as it is indeed what you brilliantly discuss in the video.

    • @dibeos
      @dibeos  4 ชั่วโมงที่ผ่านมา

      @@DaedalusCommunity hi! Thanks for the tip, we really appreciate it. Many people said that. We just changed from “why” to “how”, but please tell us: do you think that “some” would still be more appropriate? 🤔

  • @joshuawhitworth6456
    @joshuawhitworth6456 12 ชั่วโมงที่ผ่านมา +1

    I been using the Leibnitz formula which was actually discovered by someone else. If you take the products of each iteration and add them together in triangle fashion you will get pi. I have calculated pi to 26 digits using this method. You can start at any number and end at any number. The father in you start the more powerful your formula will be. If you add them together in triangle fashion you will get a number very close to pi. But no matter how far you calculate you will never reach the end. It's fun to do in your spare time. I would like to know more about the new method discovered by the string theorists. I see the formula but I don't know how to work it yet.

    • @dibeos
      @dibeos  4 ชั่วโมงที่ผ่านมา

      @@joshuawhitworth6456 wow, it sounds really cool. I’ll search more about it

  • @carbajalromerofernandoulis1053
    @carbajalromerofernandoulis1053 2 ชั่วโมงที่ผ่านมา +1

    Use an irational number to calculate another irational number, got it. Regards from Mexico

    • @dibeos
      @dibeos  2 ชั่วโมงที่ผ่านมา

      @@carbajalromerofernandoulis1053 yep, not the best approximation in the world

  • @Mariosergio61
    @Mariosergio61 17 ชั่วโมงที่ผ่านมา +1

    What I want to know is what these sequences have in relation to the ratio between the length of the circumference and the diameter.
    They seem like totally different and independent things.

    • @dibeos
      @dibeos  4 ชั่วโมงที่ผ่านมา

      @@Mariosergio61 yeah, we honestly don’t have the answer for this question. But let me think about it… maybe there is a cool geometrical connection between them and a circle somehow… 🤔

    • @dibeos
      @dibeos  4 ชั่วโมงที่ผ่านมา

      @@Mariosergio61 well, if you see the formula written in the PDF (involving cosines) of the first one (Viete), maybe we can relate each iteration to the lengths of the sides of a polygon inscribed in a circle. The more iterations, the better is the approximation to perimeter of the circle. I don’t know… it is just an idea, but we need to check whether it works or not… 🤔

  • @simondobes8570
    @simondobes8570 17 ชั่วโมงที่ผ่านมา +1

    I stumbled upon this channel purely by accident. Amazing videos! The PDF file you provided is really nice. May I ask, where are you guys from? Keep up the good work.

    • @dibeos
      @dibeos  5 ชั่วโมงที่ผ่านมา +1

      @@simondobes8570 we are glad that you enjoy our content! Well, this is always a hard question for us, but here we go: I (Luca) was born and grew up in Brazil. Since my family, from both father’s side and mother’s side, are of Italian origin, I’m Italian and Brazilian, and learned Italian from a very young age. Sofia was born in Ukraine, but spent most of her life in LA (in the US) and Moscow (in an American High School). For a few years now we have been living in Italy 😎

    • @simondobes8570
      @simondobes8570 4 ชั่วโมงที่ผ่านมา +1

      @dibeos Ohh that's wonderful! Thank you for your reply and I wish you all the best :D
      Cheers

  • @mahmoudalbahar1641
    @mahmoudalbahar1641 วันที่ผ่านมา +1

    Second comment, and I am thankful for your efforts in making these great videos, and I highly love pi and transcendental numbers.

    • @dibeos
      @dibeos  วันที่ผ่านมา +1

      @@mahmoudalbahar1641 that’s awesome!!! 😎 there is more coming in the next week…

  • @sherifffruitfly
    @sherifffruitfly 6 ชั่วโมงที่ผ่านมา

    Uh did I miss it or is that a horrible conclusion.
    If the "faster" way required 30000 calculations each iteration while the "slower" way only 3, a radically different conclusion would be reached.
    Where's the flop count?

  • @meeharbin4205
    @meeharbin4205 13 ชั่วโมงที่ผ่านมา

    Ramanujan tho...

  • @BabatopeFagbenle-rk6jy
    @BabatopeFagbenle-rk6jy วันที่ผ่านมา +1

    Lovely 🌹

  • @Speed85
    @Speed85 วันที่ผ่านมา +1

    I want a pin just pin my comment

    • @dibeos
      @dibeos  วันที่ผ่านมา +1

      @Speed85 hahahah sorry but we can pin only one comment and we need to pin the comment with the pdf link 😬

  • @medelb_w4
    @medelb_w4 วันที่ผ่านมา +1

    1st comment

    • @dibeos
      @dibeos  วันที่ผ่านมา

      Very well done 👍🏻