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The Value Of Pi — Parallax Forums

The Value Of Pi

HumanoidoHumanoido Posts: 5,770
edited 2010-11-11 01:20 in General Discussion
The Value of Pi
The value of calculating pi is important for several reasons, including a benchmark for multi-core systems.

Someone beat me to it and calculated the value of pi to one trillion digits after the decimal point and posted the results in hundreds and hundreds of 57Mb files here. It was a high school project.

PI=3.14159265358979323846264338327950288419716939937510.....


I have not checked the accuracy. There are numerous methods to calculate pi and some are more accurate than others.

The site is really fantastic, setting the 5-trillion digit world record here.

You can download the program (y-cruncher - A Multi-Threaded Pi-Program) to run on PC or LINUX here.
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Comments

  • HumanoidoHumanoido Posts: 5,770
    edited 2010-11-03 09:35
    Calculating Pi and Other Constants
    Here you can find Pi and a number of constants calculated to far reaching decimals. These also make good benchmark tests.
    The original site is here with some interesting links.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2010-11-03 10:02
    Well by all means you better check it.

    Meanwhile I have something else to do - study the Propeller Manual and Hydra programs. And maybe wash my hair.
  • K2K2 Posts: 693
    edited 2010-11-03 11:43
    Humanoido wrote: »
    The value of calculating pi is important for several reasons, including a benchmark for multi-core systems.

    Right. It would be useless as a benchmark for single-core systems. ;)
    Humanoido wrote: »
    Someone beat me to it and calculated...

    You should share more of your calculations with us. What sorts of calculations are you presently working on?
  • Dave HeinDave Hein Posts: 6,347
    edited 2010-11-03 12:27
    The basis for this thread is irrational. :)
  • HumanoidoHumanoido Posts: 5,770
    edited 2010-11-03 14:35
    K2 wrote: »
    You should share more of your calculations with us. What sorts of calculations are you presently working on?
    The calculation things are going good and I enjoy sharing. From forum responses here and here, interest is extremely low. Therefore use email.
  • mctriviamctrivia Posts: 3,772
    edited 2010-11-03 14:48
    I find it funny what we waist our time on.

    the decimal representation of pi truncated to 39 decimal places is sufficient to estimate the circumference of any circle that fits in the observable universe with precision comparable to the radius of a hydrogen atom.*Ref*


    yes it is cool to be able to say I build a computer that can compute the first trillion digits of pi. But what could these computers have been doing instead?
  • mctriviamctrivia Posts: 3,772
    edited 2010-11-03 14:49
    Humanoido wrote: »
    I'm hopefully about to launch a robot into space, if weather permits and I get clearance

    I got my copy of make magazine yesterday. Wish I had the $8000 it costs to launch your own satellite. Would be cool to have my own satellite up in orbit doing something.
  • HumanoidoHumanoido Posts: 5,770
    edited 2010-11-03 15:58
    mctrivia wrote: »
    I find it funny what we waist our time on.
    Some may say a hobby is a total waste of time, while others say you cannot put a price on personal satisfaction and pure enjoyment.

    My neighbor began putting little basa wood sticks together as a hobby. To outside eyes it may have seemed senseless and utterly ridiculous. Now he flies a model airplane. He will spend days just to get the trim perfect. It's his greatest enjoyment. He has automated the craft with robots and written the computer programs to fly it autonomously. He has become a master at robotics and programming. More of his hobbies. It can take off and land on its own. He knows a lot about aeronautics and celestial navigation. As a result he took up flying and enlisted in related courses at the university. He volunteered his time for the Life Services Rescue unit aboard helicopters and saved many lives. Last year he moved for the astronaut training program. I don't know what others think, but me, I think those little sticks in life are very important. Maybe it's just a piece of pie today, but you never know where it will lead to tomorrow.
  • mctriviamctrivia Posts: 3,772
    edited 2010-11-03 16:24
    please don't take it as an insult. I have spent countless hours drawing up Dice. I find it fun to do all the math to weight them perfectly and make something that is both unique and possible to build. My point with saying it is useless is just there is no scientific use to calculating more digits of pi. My designing dice is useless also but it is fun and it is a thrill to find out that the worlds largest dice collection has 1 of my dice in it. Don't stop doing the things you love just always keep a mind on what is more important and useful to yourself and society.
  • HumanoidoHumanoido Posts: 5,770
    edited 2010-11-03 18:37
    There is plenty of use and value in calculating lots of digits of pi. I'm using pi for the same reason that NASA uses pi. It's a worthy project of great validation.

    http://scienceray.com/mathematics/the-search-for-pi-the-work-of-centuries/
  • mctriviamctrivia Posts: 3,772
    edited 2010-11-03 18:41
    there is no use for more then 40 digits of pi. There just isn't a question that needs more accuracy then that.
  • localrogerlocalroger Posts: 3,451
    edited 2010-11-03 19:32
    mctrivia wrote: »
    there is no use for more then 40 digits of pi. There just isn't a question that needs more accuracy then that.

    There isn't a physical use for more than 40 digits of PI. In math, who knows? One could say there's no physical use for tiny little slices of numerical analysis being taken beyond some similar threshold, but take them to infinity, solve the resulting equation, and behold! You have Calculus, which reveals whole new ways to manipulate numbers -- and those seem to describe the real world too, with much greater utility than anyone might intuitively expect.
  • HumanoidoHumanoido Posts: 5,770
    edited 2010-11-03 20:43
    Well by all means you better check it.
    Meanwhile I have something else to do - study the Propeller Manual and Hydra programs. And maybe wash my hair.
    Indeed. Some of the Pi algorithms error out after a hundred decimals. A situation like that could be devastating if it's being used to gauge the computational accuracy of a new machine. Most of the historical routines have some bug. There is an entire website devoted to error checking of the Pi constant. Did you study the pi constant on pages 93 and 94 in the Propeller Manual? ($40490FDB) It seems like days now, I hope you finally have clean hair. One local guy I knew felt some itchy thing crawling in his hair and reached up there to find out what it was. It was a giant Tarantula spider with fangs, sets of blackish hairy 8-inch long legs spanning a body width of 19-inches that had dropped down from somewhere above. In these hot humid climates they can live longer, grow larger, and bite harder. Did you say you have an itch? :)
  • HumanoidoHumanoido Posts: 5,770
    edited 2010-11-03 21:06
    mctrivia wrote: »
    I find it funny what we waist our time on.
    I find it funny that ironically, it's more time that we should spend on our waist, at the gym. :lol:
  • mctriviamctrivia Posts: 3,772
    edited 2010-11-03 21:09
    that is why i use my tread mill while watching TV. to bad I missed Caprica episode 14 :(
  • HumanoidoHumanoido Posts: 5,770
    edited 2010-11-03 21:31
    mctrivia wrote: »
    I have spent countless hours drawing up Dice. My designing dice is useless...
    You sly devil. This is just spam! Your, as you say "useless dice," is listed on that linked web site in numerous places for sale!
  • mctriviamctrivia Posts: 3,772
    edited 2010-11-03 21:37
    The dice are not useless(well except for the 4D ones) they are fully functional. Me spending 10 hours to design some of them is useless since I spend more money then I make and I do not ever expect to make a profit. I do it for fun and because I can.

    In the same way knowing pi is usefull. Knowing more then 40 digits isn't.
  • HumanoidoHumanoido Posts: 5,770
    edited 2010-11-03 21:38
    There's a transcendental analysis of Pi here.
    [FONT=Arial, Helvetica, sans-serif]By definition, the number [/FONT][FONT=Arial, Helvetica, sans-serif]pi.GIF[/FONT][FONT=Arial, Helvetica, sans-serif] is the ratio of the circumference to the diameter of a circle. This ratio is the same for all circles. pi.GIF[/FONT][FONT=Arial, Helvetica, sans-serif] is an irrational number. It cannot be represented as the ratio of two integers, regardless of the choice of integers. Equivalently, it cannot be represented as an unending, periodic decimal. pi.GIF[/FONT][FONT=Arial, Helvetica, sans-serif] is also a transcendental number. It is not a root of any algebraic equation of the form[/FONT]
    [FONT=Arial, Helvetica, sans-serif]a0 + a1x + a2x2 + … + anxn = 0 ...[/FONT]
  • mctriviamctrivia Posts: 3,772
    edited 2010-11-03 21:45
    i guess one use of computing more digits of pi is to see if pi is indeed irrational. as far as I know no one has ever proven that it is. sqrt of 2 has been proven mathematically but pi has not. Admittedly I have not searched in the last 5 years so please correct me if I overlooked a breakthrough since then.
  • HumanoidoHumanoido Posts: 5,770
    edited 2010-11-03 22:13
    mctrivia wrote: My designing dice is useless
    mctrivia wrote: The dice are not useless

    If this were inline skating I would say you just did a 180. I think the dice are extremely useful, which is my original point, especially the ones that you spend 10 hours on designing, because, well, wow, look at those, they have more interesting and intricate shapes which are much more beautiful and aesthetically pleasing, mathematical in nature, puzzling, modern and artistically useful.

    If you made these on a larger scale they would display well at art galleries and probably fetch thousands of dollars to adorn elitist futuristic homes. Even some murals would be totally fascinating especially in 3D. I'd say if you wear glasses, they must be on backwards to see everything in such a negative dim light, when in reality you're looking at the bright positive gems of the universe.

    When you find such interesting things in this world, displaying the creative talent that you have with dice and capabilities to understand the deeper meaning of Pi, you just have to envision not only the positive but the usefulness as well. Look how you turned numbers into great works of admiration and value. The world is big. There's plenty of space for both. I also see something of great beauty and usefulness in Pi.
  • HumanoidoHumanoido Posts: 5,770
    edited 2010-11-03 22:37
    mctrivia wrote: »
    i guess one use of computing more digits of pi is to see if pi is indeed irrational. as far as I know no one has ever proven that it is. sqrt of 2 has been proven mathematically but pi has not. Admittedly I have not searched in the last 5 years so please correct me if I overlooked a breakthrough since then.
    See my post above on the transcendental nature of Pi. For more information, consult the sites below.

    Proof that Pi is irrational, From Wikipedia
    Although the mathematical constant known as π (pi) has been studied since ancient times, and so has the concept of irrational number, it was not until the 18th century that Johann Heinrich Lambert proved that π is irrational. In the 20th century, proofs were found that require no prerequisite knowledge beyond integral calculus. One of those, due to Ivan Niven, is widely known. A somewhat earlier similar proof is by Mary Cartwright.[1]

    Pi is Irrational, Projects by Students for Students
    For many centuries prior to the actual proof, mathematicians had thought that pi was an irrational number. The first attempt at a proof was by Johaan Heinrich Lambert in 1761. Through a complex method he proved that if x is rational, tan(x) must be irrational. It follows that if tan(x) is rational, x must be irrational. Since tan(pi/4)=1, pi/4 must be irrational; therefore, pi must be irrational.

    Why is Pi irrational, from Ask
    Pi can't be expressed as a fraction (a ratio of two integers), which makes it irrational. Pi (π) is an irrational number; it's trancendent. The mathematical proof that pi is irrational can be viewed by using the link to the Wikipedia article on exactly this topic. The challenge is that to understand the proof, one needs some familiarity with integral calculus. Short of that, one would probably have to just accept the fact that pi is transcendent and that it has been proved. (Pi was suspected to be irrational from ancient times, but it was actually proved to be in the 1700's.)
  • mctriviamctrivia Posts: 3,772
    edited 2010-11-03 22:51
    well it seems I have been believing a lie for the last 5 years. I believed it was irrational but not proven. Do you have any suggested uses for knowing the 5 trillionth digit of pi? I tend to use 355/133 unless there is a built in PI value.

    I like the way you describe my dice. I just want to point out the following:

    mctrivia wrote: My designing dice is useless
    mctrivia wrote: The dice are not useless

    these are not opposing statements. one is talking about the act of creating the other is talking about the actual physical object(even if most of them are really just 50,000-500,000 triangles stored on a computer. They definitely have a lot to do with pi since the formulas used to define the circles is
    d=2*sqrt(V/(n*PI)) where n is the side number and V is a constant chosen to make sides 2 and 3 possible. Though I usually chose a value of V that is a multiple of PI to simplify the formula. :) PI is everywhere.
  • HumanoidoHumanoido Posts: 5,770
    edited 2010-11-03 23:11
    mctrivia wrote: »
    Do you have any suggested uses for knowing the 5 trillionth digit of pi?
    The significant use is not in knowing the trillionth digit value but how you got there. Perhaps the best use of calculating Pi to such high decimal places is one of verification, i.e. to determine the accuracy of a new machine in terms of computational ability, repeatability, and speed. If you remember back some time that NASA made a costly purchase from IBM and found all those new PCs (that were already interfaced to the Space Shuttle flight control system) had defective CPU chips in terms of computational ability. You will see at the NASA link that a program to calculate Pi is a test to validate new machines in the US Space Program since the 1980s.
  • Beau SchwabeBeau Schwabe Posts: 6,566
    edited 2010-11-03 23:31
    I find the last sentence in this Wikipedia citation on pi very intriguing...

    "Despite much analytical work, and supercomputer calculations that have determined over 1 trillion digits of the decimal representation of π, no simple base-10 pattern in the digits has ever been found."

    ... could it be we've been searching all this time for a 'pi pattern' to emerge in the wrong base numbering system. :-) ... how daft we must be.
  • HumanoidoHumanoido Posts: 5,770
    edited 2010-11-03 23:32
    mctrivia wrote: »
    I tend to use 355/133 unless there is a built in PI value.
    Why? I think you want to say 355/113.

    355/133 = 2.669172932330827
    355/113 = 3.141592920353982


    Here are some algorithms for Pi approximations at the Wolfram Mathworld site. Some are quite involved to remember.

    Two other simple approximations are 3 and 22/7.
    Or remember more digits for more accuracy.

    103993/33102 = 3.141592653011903


    For Pi accuracy comparison,
    here are the first 50 decimal places found at Wikipedia.
    3.14159 26535 89793 23846 26433 83279 50288 41971 69399 37510
  • mctriviamctrivia Posts: 3,772
    edited 2010-11-03 23:33
    you are correct. it is to early in the morning. I am putting my blackberry in silent and going to bed. Will catchup with you in 6 hours.

    patterns in pi have been found in base 16

    attachment.php?attachmentid=74718&stc=1&d=1288148933
  • HumanoidoHumanoido Posts: 5,770
    edited 2010-11-03 23:47
    I find the last sentence in this Wikipedia citation on pi very intriguing... "Despite much analytical work, and supercomputer calculations that have determined over 1 trillion digits of the decimal representation of π, no simple base-10 pattern in the digits has ever been found." ... could it be we've been searching all this time for a 'pi pattern' to emerge in the wrong base numbering system. :-) ... how daft we must be.
    Beau, you must be talking about the reoccurring pattern in Pi HEX. From the same Wiki site:

    Pi Hex was a project to compute three specific binary digits of π using a distributed network of several hundred computers. In 2000, after two years, the project finished computing the five trillionth (1012), the forty trillionth, and the quadrillionth (1015) bits. All three of them turned out to be 0.

    Beau, take a look at Stu's page for Pi in base 3. Definitely lots of patterns in this small clip. See also other base systems such as base 9, base 16 and base 36.

    Pi in Base 3 (trinary)
    10.010211012222010211002111110221222220111201212121200121100100101222022
    212012012111210121011200220120210000101022010020111120002221022201100101
    110121101201010001000222021220110022122210112222212102022011020121022202
    201202222120121200201112210000112022001212201101110122210211002112122121
    211222122110212212110100221202121011001210210011011102222020021111121010
    210000020112212201001211102202212200120020020010012100101122200022202110
    211210122110122112120220000111101200101111122000201122111122201010211221
    111022122212101200222102212122011001202022112000020111212020200000020222
    210021220021011101201122121102000010102101100200202220202100122000010000...

    Perhaps the real debate is do you see a pattern for Pi in base Pi? :)
  • HumanoidoHumanoido Posts: 5,770
    edited 2010-11-03 23:55
    mctrivia wrote: »
    you are correct. it is to early in the morning. I am putting my blackberry in silent and going to bed. Will catchup with you in 6 hours.

    patterns in pi have been found in base 16

    attachment.php?attachmentid=74718&stc=1&d=1288148933

    The formula sure beats looking at the actual numbers, or can you spot the patterns?

    Pi in Base 16 from Stu's web site
    3.243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89452821
    E638D01377BE5466CF34E90C6CC0AC29B7C97C50DD3F84D5B5B54709179216D5D98979FB
    1BD1310BA698DFB5AC2FFD72DBD01ADFB7B8E1AFED6A267E96BA7C9045F12C7F9924A199
    47B3916CF70801F2E2858EFC16636920D871574E69A458FEA3F4933D7E0D95748F728EB6
    58718BCD5882154AEE7B54A41DC25A59B59C30D5392AF26013C5D1B023286085F0CA4179
    18B8DB38EF8E79DCB0603A180E6C9E0E8BB01E8A3ED71577C1BD314B2778AF2FDA55605C
    60E65525F3AA55AB945748986263E8144055CA396A2AAB10B6B4CC5C341141E8CEA15486
    AF7C72E993B3EE1411636FBC2A2BA9C55D741831F6CE5C3E169B87931EAFD6BA336C24CF
    5C7A325381289586773B8F48986B4BB9AFC4BFE81B6628219361D809CCFB21A991487CAC
    605DEC8032EF845D5DE98575B1DC262302EB651B8823893E81D396ACC50F6D6FF383F442
    392E0B4482A484200469C8F04A9E1F9B5E21C66842F6E96C9A670C9C61ABD388F06A51A0
    D2D8542F68960FA728AB5133A36EEF0B6C137A3BE4BA3BF0507EFB2A98A1F1651D39AF01
    7666CA593E82430E888CEE8619456F9FB47D84A5C33B8B5EBEE06F75D885C12073401A44
  • Beau SchwabeBeau Schwabe Posts: 6,566
    edited 2010-11-03 23:55
    Ok, so there ARE patterns, but to be analogous to what I was trying to convey, or at least my thought on it.

    ... The base numbering systems that we try to throw at pi are all flat or 2d representations (conversions from one base to another basically)

    ... When/if we ever hit on the right formula to 'unravel' pi, it will be like tuning in a crystal clear radio station and there will absolutely be no doubt to the solution. Until then ... well...
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2010-11-04 00:26
    I'm sure it's illegal to compute pi to too many decimal places. As with Borges' "The Library of Babel", the indefinite expansion of pi, converted to ASCII, must certainly include every copyrighted work ever published. For this reason, according to the Digital Millenium Copyright Act, possession of a program capable of such a feat of expansion would also be a crime. Moreover, I suspect that, by broaching the subject in a public forum, Humanoido would be deemed guilty of "contributory malfeasance by way of inducement," or some such legalese. But I won't tell! :)

    -Phil
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