×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

cancel ×
This is a preview of your comment

No Comment Title Entered

Anonymous Coward 1 minute ago

No Comment Entered

204 comments

Verification (3, Interesting)

Tukz (664339) | more than 4 years ago | (#30652224)

I didn't read the article, only the summery but it made me wonder.

Do they verify these numbers somehow?
Anyone can write down a series of a numbers and claim it's a specific sequence.

Not saying these numbers aren't correct, just a thought.

One thing to say (5, Informative)

DirtyCanuck (1529753) | more than 4 years ago | (#30652250)

From the FAQ

"How does your record compares to the previous one ?
The previous Pi computation record of about 2577 billion decimal digits was published by Daisuke Takahashi on August 17th 2009. The main computation lasted 29 hours and used 640 nodes of a T2K Open Supercomputer (Appro Xtreme-X3 Server). Each node contains 4 Opteron Quad Core CPUs at 2.3 GHz, giving a peak processing power of 94.2 Tflops (trillion floating point operations per second).

My computation used a single Core i7 Quad Core CPU at 2.93 GHz giving a peak processing power of 46.9 Gflops. So the supercomputer is about 2000 times faster than my computer. However, my computation lasted 116 days, which is 96 times slower than the supercomputer for about the same number of digits. So my computation is roughly 20 times more efficient. It can be explained by the following facts:

        * The Pi computation is I/O bound, so it needs very high communication speed between the nodes on a parallel supercomputer. So the full power of the supercomputer cannot really be used.
        * The algorithm I used (Chudnovsky series evaluated using the binary splitting algorithm) is asymptotically slower than the Arithmetic-Geometric Mean algorithm used by Daisuke Takahashi, but it makes a more efficient use of the various CPU caches, so in practice it can be faster. Moreover, some mathematical tricks were used to speed up the binary splitting. " ( http://bellard.org/pi/pi2700e9/faq.html [bellard.org] )

Mathematical and Programming Ownage.

Re:One thing to say (1, Insightful)

Anonymous Coward | more than 4 years ago | (#30652414)

Interesting, but it didn't really answer the question.

Re:One thing to say (0)

Anonymous Coward | more than 4 years ago | (#30652502)

They ran some verification tests, but admitted that since his memory doesn't have error correction there's some possibility of error. The initial verification test crashed one of the computers, and would have taken quite some time to re-complete.

Re:One thing to say (3, Interesting)

HateBreeder (656491) | more than 4 years ago | (#30652804)

I would assume he only needs to verify the last 120 billion digits.

Assuming his algorithm can support serialization of its state into a check-point, he can simply recalculate the last 120 billion digits a couple of times and compare.

Assuming linear time to compute each digit: 120e9/2.7e12 * 116 =~ 5 days. not too bad.

Re:One thing to say (2, Interesting)

Lord Lode (1290856) | more than 4 years ago | (#30653228)

Hmm, for such a record attempt, do you actually have to calculate all these earlier digits? They're already known. Can anyone prove the computer calculated the already known digits first (instead of getting them from a table) before finally getting to the 120 million new ones?

Re:One thing to say (1)

MrMr (219533) | more than 4 years ago | (#30653250)

Worse than that, I find it extremely unlikely that not a single bit failed in uncorrected memory during the whole 116 days...
see for instance:here [cnet.com]

Re:One thing to say (4, Funny)

Anonymous Coward | more than 4 years ago | (#30652436)

HE USED TRICKS!!!!1111Burn the witch...eehh communist...eeeh climate researcher...eeeeh....PI guy.

Re:One thing to say (1)

PingPongBoy (303994) | more than 4 years ago | (#30652440)


The Pi computation is I/O bound, so it needs very high communication speed between the nodes on a parallel supercomputer. So the full power of the supercomputer cannot really be used.

The algorithm I used (Chudnovsky series evaluated using the binary splitting algorithm) is asymptotically slower than the Arithmetic-Geometric Mean algorithm used by Daisuke Takahashi, but it makes a more efficient use of the various CPU caches, so in practice it can be faster.

Before the next Top 500 list is published in June, maybe the benchmarking needs to be shaken up a little, huh? Intuition suggests the supercomputer could be reprogrammed to calculate more digits by a few orders of magnitude. We still have a lot to learn when it comes to taken advantage of multiprocessors, as well as algorithms.

Re:One thing to say (4, Insightful)

digitalhermit (113459) | more than 4 years ago | (#30652682)

In another thread someone had posted that there was no reason for any modern CPUs; the idea being that anything one could reasonably want to do with a computer was possible with decade old hardware.

This.. *This* article is why I enjoy the breakneck pace of processor speed improvements. The thought of being able to do some pretty serious computing on a relatively inexpensive bit of hardware -- even if it takes half a year to get results -- does what the printing press did. It allows the unwashed masses (of which I am one) a chance to do things that were once only the realm of researchers in academia or the corporate world. Sure, all that you need to do some serious mathematics is a pen and paper, but more and more discoveries occur using methods that can only be performed with a computer.

There's always the argument that cheap computers and cheap access to powerful software pollutes the space with hacks and dilletantes. People have said this about desktop publishing, ray tracing, and even the growth of Linux. But it's this ability to do some amazing things with computers that makes it all worthwhile.

Re:One thing to say (0)

Anonymous Coward | more than 4 years ago | (#30652872)

Well, it is a neat thing that he has done, but what are you going to compare those 2700 trillion digits to?What kind of problem can you solve only if you know the 2000 000 000 000 000 th digit of pi?

But you are right about the CPUs. Anyone who thinks that CPUs are good enough would have to explain why most mobile devices run out of battery charge in less than a day even though their UIs are sluggish and their apps not very advanced. We need a little bit more speed and a lot less energy consumption.

Re:One thing to say (1)

Ego_and_his_own (1704208) | more than 4 years ago | (#30653020)

There is something in Pi that is far beyond numbers. It hides an answer to some questions for sure. It puts math on abstract side of reality. Pi is weird....

Re:One thing to say (3, Funny)

Le Marteau (206396) | more than 4 years ago | (#30653184)

> It hides an answer to some questions for sure.

Could be. I'm not sure the answer will be in base 10, though.

Maybe, in base 36, beginning at the trillionth digit, pi is:

"URTEHSUXXORUNEED2GETALIFESRSLYKTHXBYE"

That would be amazing.

Re:One thing to say (1)

Le Marteau (206396) | more than 4 years ago | (#30653242)

Seriously, though... rather than going off into trying to pushing the limit on how many digits can be cranked out for pi, would it not be more interesting and perhaps more fruitful to search for patterns, in numerous bases, in pi? Maybe there really IS "an ultimate answer" in some other base, just waiting for some geek in his mother's basement with an old Packard Bell to invest the energy.

Or maybe pi will end up just being a bunch of zeros or something after X many digits.

Either way, I'm sure it would make the front page of /.

Re:One thing to say (1)

dch24 (904899) | more than 4 years ago | (#30653118)

Come on... think a little.

What does large number theory, factorization, optimizations that offer 2000x speedups in this field, and specific information for desktop computers ... what is it about?

Go watch Sneakers [imdb.com] again.

Re:Verification (3, Informative)

msclrhd (1211086) | more than 4 years ago | (#30652412)

In TFA (especially the PDF), the verification method is to use another algorithm to check the output. The PDF on Fabrice's home page goes into more details.

NOTE: The machine they were using to generate the second result broke, so they used another (3rd) algorithm to generate the last digits.

Re:Verification (4, Interesting)

David Jao (2759) | more than 4 years ago | (#30652444)

I didn't read the article, only the summery but it made me wonder.

Do they verify these numbers somehow? Anyone can write down a series of a numbers and claim it's a specific sequence.

Not saying these numbers aren't correct, just a thought.

Perhaps this is why you should read the article. The press release [bellard.org] answers this question directly.

The binary result was verified with a formula found by the author with the Bailey-Borwein-Plouffe algorithm which directly gives the n'th hexadecimal digits of Pi. With this algorithm, the last 50 hexadecimal digits of the binary result were checked. A checksum modulo a 64 bit prime number done in the last multiplication of the Chudnovsky formula evaluation ensured a negligible probability of error.

The conversion from binary to base 10 was verified with a checksum modulo a 64 bit prime number.

Re:Verification (1)

Xest (935314) | more than 4 years ago | (#30652528)

You don't need to verify that the number is correctly pi to the given digits, merely verify that the algorithm calculates the digits of pi correctly.

The algorithm can be proven correct in a number of relatively quick and easy ways.

The algorithm is really also arguably the most important part anyway rather than the digits themselves because it's the part of most use.

Re:Verification (1)

KowShak (470768) | more than 4 years ago | (#30652688)

The mathematical algorithm may be correct, but is the implementation of it correct and how do you verify it?

A computer program can not be proven to be correct in a number of relatively quick and easy ways.

Re:Verification (1)

SlothDead (1251206) | more than 4 years ago | (#30652972)

That does not really matter at all. It's not about getting a lot of correct digits of Pi.

Re:Verification (1)

dch24 (904899) | more than 4 years ago | (#30653124)

Breaking the record brings attention to the algorithm.

It means that the algorithm will get noticed.

Re:Verification (2, Interesting)

Xest (935314) | more than 4 years ago | (#30653196)

The implementation (compiled or uncompiled) is in itself an algorithm which can equally be checked because the language follows pre-defined logical rules which may act as axioms or depending on the details of the algorithm it may be trivial to just use induction.

It's not like we're checking a full operating system or office suite here, so size isn't a restrictive problem in such a proof.

It may be that the processor itself hasn't been checked so that the results of executing that algorithm isn't correct either, but again, when it's the algorithm that matters, who cares? We know the specifications of the language which may effectively act as axioms in a proof. The compiler may not be valid certainly, but as long as the algorithm (yes, mathematical and implementation) is correct then that is what matters.

It is down to anyone then using the algorithm to ensure the other layers are correct enough for their purposes.

Re:Verification (0)

Anonymous Coward | more than 4 years ago | (#30652936)

hrmph..., by your reasoning software bugs should not have to exist.

You would instantaneously receive a Turing Award and a Nobel prize for Economics if you are able to keep your promise.

Re:Verification (1)

Xest (935314) | more than 4 years ago | (#30653060)

No, because most software is large and complex, doing things like mathematical induction on all code is infeasible for this reason.

In contrast, code to calculate something like this is relatively extremely small.

Effectively, the reason your argument doesn't hold is that although we can fairly trivially prove some algorithms correct, the method isn't scalable and hence doesn't scale to the scale of pretty much any piece of modern software.

Re:Verification (0)

Anonymous Coward | more than 4 years ago | (#30652738)

It'll hardly matter when it's rounded to two significant places.

first posssttt (-1, Offtopic)

Anonymous Coward | more than 4 years ago | (#30652238)

it used windows ninghty 888

Finally! (5, Funny)

pEBDr (1363199) | more than 4 years ago | (#30652266)

Now I can finally get somewhat reasonable precision when calculating the radius of stuff!

Re:Finally! (1)

Opportunist (166417) | more than 4 years ago | (#30652316)

It's still waaaaaaaay off.

Can't get precision anymore these days, everything's just rush-rush, nobody takes the time to do it right...

Re:Finally! (1)

WillyDavidK (977353) | more than 4 years ago | (#30652454)

Too bad you'll need to upgrade your TI-83 to about 1.2TB of storage space to manipulate the number! And I hope you have some AAs that can last a few years under load...

Re:Finally! (0)

Anonymous Coward | more than 4 years ago | (#30652558)

I use a Casio FX-9860G, You insensitive clod!

Re:Finally! (0)

Anonymous Coward | more than 4 years ago | (#30652776)

HP48GX FTW! (I know

Re:Finally! (2, Funny)

asc99c (938635) | more than 4 years ago | (#30652758)

You'd also need something to prop up the other end of the new extended screen to display the number - Venus should be in about the right place when it gets a bit closer!

Re:Finally! (2, Interesting)

Anonymous Coward | more than 4 years ago | (#30652960)

There is a program package for Linux called Sage math where you can get a lot of digits in your constants. For example, to accurately calculate the circumference of a circular table with diameter=1000 mm you could type:

1000*pi().n(digits=1000000)

All you need now is a decent measuring tape...

These two also work, in case you're worried about not getting good enough accuracy when you calculate Fourier coefficients or something:

(pi().n(digits=1000000))^2
(pi().n(digits=1000000))^3

Since Sage sets up a web server on your computer you can even do this inside a decent phone web browser, so you can get that precision out in the field, where you need it. :-)

Re:Finally! (0)

Anonymous Coward | more than 4 years ago | (#30653008)

yeah, better not use the TI-83 then, because of the lack of a usb port. it would take some heave cracking to get an external hard drive through that minijack. I'd recommend the TI-89 since it's got a mini usb port.

Re:Finally! (1, Funny)

Anonymous Coward | more than 4 years ago | (#30653240)

I still use the "old math", where you "measure" the radius. Now you kids calculate the radius with pi?

BTW, get off my lawn ...

Wow... (1)

LostCluster (625375) | more than 4 years ago | (#30652274)

They figured this out... they post some, not all of the data, and therefore survive the slashdotting.

Re:Wow... (3, Interesting)

MichaelSmith (789609) | more than 4 years ago | (#30652288)

Plain html is a wonderful thing. And as he points out, it would be easy to write a cgi script which returns a specified block of digits.

I wonder if he has checked for the circle?

Re:Wow... (1, Funny)

Anonymous Coward | more than 4 years ago | (#30652686)

Plain html is a wonderful thing.

yes, but why not do it in javascript? generating those digits on the fly is much more efficient from a slashdotting perspective.

Re:Wow... (1)

CraterGlass (893417) | more than 4 years ago | (#30653080)

Someone should check it for ASCII codes. Somewhere in there it probably says "Help! I'm being held prisoner in a universe factory!". (kudos to XKCD)

this guy has a pretty impressive track record (5, Informative)

Trepidity (597) | more than 4 years ago | (#30652280)

For those not previously familiar with Fabrice Bellard, he's known for:

  • LZEXE [bellard.org] , very popular in the early 1990s as the first EXE-shrinker for DOS, or at least the first widely available one
  • ffmpeg [ffmpeg.org] , video decoding library which he started and headed for a number of years
  • QEMU [nongnu.org] , dynamic-translating generic emulator

Re:this guy has a pretty impressive track record (5, Informative)

msclrhd (1211086) | more than 4 years ago | (#30652492)

He also wrote the Obfuscated Tiny C Compiler (http://bellard.org/otcc/) in 2002 for the Obfuscated C contest, where otcc could compile itself. This became the Tiny C Compiler (TCC) which was picked up by Robert Landley (but subsequently dropped a while later) that is a capable, fast C90/C99 compiler.

His projects page (http://bellard.org/) and the older projects (http://bellard.org/projects.html) contain a lot of interesting projects.

Also of note: Fabrice achieved the record for Pi computation in 1997 as well:
      http://bellard.org/pi/pi_hexa.html [bellard.org]
      http://bellard.org/pi-challenge/announce220997.html [bellard.org]
      http://bellard.org/pi/ [bellard.org]

I'm not impressed - Superman was faster than a (2, Funny)

anti-NAT (709310) | more than 4 years ago | (#30652540)

speeding bullet, and was able to leap tall buildings in a single bound. Fabrice needs to lift his game.

Specs from the PC in question (4, Informative)

c0mpliant (1516433) | more than 4 years ago | (#30652302)

Core i7 clocking at 2.93GHz 6GB RAM 5 1.5TB Hard Drives (At least 7.2TB needed to store final result and base conversion)

He will be releasing the program he created for Windows (64bit only) and Linux

silly (1, Flamebait)

dsanfte (443781) | more than 4 years ago | (#30652332)

There is an algorithm now for calculating the nth digit of Pi at a whim.

This is slightly retarded.

Re:silly (5, Informative)

Trepidity (597) | more than 4 years ago | (#30652348)

As he points out himself, he doesn't really care about calculating digits of Pi; it's a convenient hook on which to hang an interesting algorithms challenge. From the FAQ:

I am not especially interested in the digits of Pi, but in the various algorithms involved to do arbitrary-precision arithmetic. Optimizing these algorithms to get good performance is a difficult programming challenge.

He also mentions elsewhere that of his code, "The most important part is an arbitrary-precision arithmetic library able to manipulate huge numbers stored on hard disks."

Re:silly (1)

i.of.the.storm (907783) | more than 4 years ago | (#30652512)

Yeah, it's more interesting how he exploited caching to good effect with his algorithm. This is not something we hear about all that often.

Re:silly (3, Insightful)

David Jao (2759) | more than 4 years ago | (#30652428)

There is an algorithm now for calculating the nth digit of Pi at a whim.

The algorithm [wikipedia.org] only works for hexadecimal digits. There is no known formula or algorithm for calculating the n-th decimal digit directly.

Having said that, the existence or non-existence of an n-th digit algorithm does not have any relevance on the silliness or non-silliness of computing trillions of digits of pi, unless the algorithm is extremely trivial (i.e. computing the digit takes less CPU time than a byte of I/O), which is not the case here.

Re:silly (4, Informative)

Ambiguous Puzuma (1134017) | more than 4 years ago | (#30652842)

There is no known formula or algorithm for calculating the n-th decimal digit directly.

What about this [arxiv.org] ?

I present here a way of computing the nth decimal digit of pi (or any other base) by using more time than the [BBP] algorithm but still with very little memory.

Re:silly (2, Interesting)

Bacon Bits (926911) | more than 4 years ago | (#30652782)

Knowing how to calculate the nth digit of Pi itself is slightly retarded.

The observable universe is about 50 billion light years across, which is about 4.27 * 10^26 meters. If we take a ring of atoms each roughly 1 Angstrom (10^-10 meters) apart with a diameter the size of the observable universe and want to determine the circumference of the resulting circle, then knowing Pi to 40 or so places is sufficient that the error caused by the atoms themselves is greater than that introduced by using an approximate value for Pi. Knowing Pi to 40 or so places is sufficient that you can calculate the difference in circumferences of the inner diameter of the ring and outer diameter of the ring.

Knowing Pi to 40 places is basically sufficient for describing our entire universe and anything you could put into it. We've known the first 35 for four hundred years, and we've never needed that much information to describe our universe.

Re:silly (0)

Anonymous Coward | more than 4 years ago | (#30652870)

Yes, 40 digits is good for everything. As long as you never do any sort of iterative process.

Re:silly (1)

AlecC (512609) | more than 4 years ago | (#30653142)

But pi seems to have to do with more than geometry. It seems to be embedded in the structure of space and particle physics in some way we do not really understand. That said, of course we will never be able to make measurements whose total range is more than a few tens of orders of magnitude, so for physics, a short approximation is adequate. But mathematics exists in its own right - the fact that it serves physics has always been secondary (to mathematicians).

Re:silly (0)

Anonymous Coward | more than 4 years ago | (#30652920)

There is an algorithm now for calculating the nth digit of Pi at a whim.

Not in decimal, there isn't. The Borwein-Bailey-Plouffe algorithm [wolfram.com] only works on base 16. There are others [wolfram.com] for base 2, 64, and 729, but not 10.

Re:silly (1)

Tim C (15259) | more than 4 years ago | (#30652922)

That's like saying that the fact that we have horses and cars, etc, make hiking or cycling anywhere retarded.

Sometimes the point isn't the destination, it's the journey.

Re:silly (1)

AlecC (512609) | more than 4 years ago | (#30653134)

And he used that algorithm to verify his result by checking the last 50 digits.But, presumably, the algorithm he used for calculating the whole block is faster than this arbitrary algorithm, so it would not have generated his billions of digits in the time he has actually taken. The achievement is to calculate all those digits on relatively low powered hardware, not any particular bits.

So... umm... (-1)

Opportunist (166417) | more than 4 years ago | (#30652334)

Well, 'til now I saw the Pi-calculating e-peen waving as something like basic research. Ya know, where you build better computers and then you don't find anything sensible to do with them, so let's have them, say, find the next big prime (ok, being in cryptography I can see an application for that...) or have them calculate Pi to another few more billion spaces. Ya know, something that takes ages and is a great burn-in test.

This time it's not a better computer. He used an existing computer and (again, I have to say) found a better algorithm for something. A better algo that made better use of the architecture. And while great, it does not really serve any purpose, unless knowing Pi to another few more billion spaces actually is a purpose.

Could someone fill me in what purpose that may be?

Re:So... umm... (3, Insightful)

MichaelSmith (789609) | more than 4 years ago | (#30652352)

Could someone fill me in what purpose that may be?

Because.

Re:So... umm... (4, Informative)

JasterBobaMereel (1102861) | more than 4 years ago | (#30653236)

Basic research ..... you know that stuff that has no useful application now .....especially maths

Like group theory, invented in 1832 by Évariste Galois, had no really useful application until the mid 20th century ... Now quantum mechanics and so most of modern electronics uses it ....

Re:So... umm... (3, Informative)

Trepidity (597) | more than 4 years ago | (#30652366)

He mentions in the "press release" page that the most important thing developed in his code is "an arbitrary-precision arithmetic library able to manipulate huge numbers stored on hard disks", which sounds basic-research-y. There's some more on that in the technical-details PDF, although unfortunately he says he doesn't plan to release the code (somewhat unusual, since most of his projects are free software).

Re:So... umm... (0, Insightful)

Anonymous Coward | more than 4 years ago | (#30653200)

although unfortunately he says he doesn't plan to release the code (somewhat unusual, since most of his projects are free software).

More than unusual - it also means that for all practical purposes, his record is worthless. If we cannot look at the program he used to calculate these digits and verify (i.e., prove) that it's actually correct, what have we actually gained?

Without the program OR the data, all we really have is one guy's claim that he set a new world record, in secret, with the result not even available.

Now, I have no reason to distrust Bellard, and I don't really doubt he really did what he claims to have done; make no mistake about that. I don't think he's lying or anything, but I'd like to be able to verify what he did for myself, or at least have the possibility to. That's what science works like.

Re:So... umm... (1)

msclrhd (1211086) | more than 4 years ago | (#30652550)

Improving the algorithms for arbitrary precision arithmetic -- that is the area that Fabrice is interested in, not necessarily computing X number of digits of pi. That, and (a) it is interesting, (b) it is a challenge and (c) let's do it for fun.

Did he find a message? (1)

wisebabo (638845) | more than 4 years ago | (#30652424)

I believe in "Contact" (the book by Carl Sagan, not the movie), the travelers ask the superintelligent aliens "Do you believe in God? To which they reply: "Yes" When asked why, they say "We have proof" in the finding of a message in a transcendental number (pi?).

After reading the Wikipedia summary I understand that when the travelers come home and are accused of fabricating the whole thing, one of them tries to "find" this message by running their own computer program. She finds a message, or does she? Is it just a (very unlikely?) statistical fluke? What is noise and what is message when you are dealing with a literally infinitely long string of numbers? (Wasn't this also the plot behind one of Stanislaw Lem's books?).

I guess if he found a message the news would be all over the place by now so he didn't find a message (or maybe he's just keeping the insights to himself for stock market gains like in the movie "Pi"). Anyway, how DO you go about finding patterns in a finite (if you can call 2.7 trillion finite!) string of numbers?

Re:Did he find a message? (0)

Anonymous Coward | more than 4 years ago | (#30652848)

You must be a LISP programmer (or am I mistaken?)

So.... (0, Troll)

WillyDavidK (977353) | more than 4 years ago | (#30652474)

So what exactly has been accomplished here?

Re:So.... (2, Informative)

Fjodor42 (181415) | more than 4 years ago | (#30652596)

Read... The... Fine... (wait for it) Article!

Spoiler alert!

He developed a highly efficient library for arbitrary precision floating-point number calculations, capable of having a desktop machine best a supercomputer. Now go change your signature to "For lack of a better question..." ;-)

not something revolutionary (0)

Anonymous Coward | more than 4 years ago | (#30652562)

from the article :

Technologies relevant to the objectives of the TX program can be found in numerous disciplines and areas of research including: adaptive wing structures, ducted fan propulsion, lightweight composite materials, advanced flight control technology for stable transition from vertical to horizontal flight, hybrid electric drive, advanced batteries, and others.

so no, they didn't waterboard the greenies :(

Pattern? (0, Redundant)

Silpher (1379267) | more than 4 years ago | (#30652584)

If you would put the outcomes in a graph would a pattern arise? If there is a predictable pattern perhaps computation could go a lot faster, but then I guess they would have figured that out by now. ( Or maybe I should call him? :P )

Re:Pattern? (2, Interesting)

Trepidity (597) | more than 4 years ago | (#30652626)

Depends on what you mean by "pattern", of course, but pi is conjectured to be normal [wikipedia.org] , which would exclude many sorts of patterns. It's not proven, though.

Re:Pattern? (1)

vorlich (972710) | more than 4 years ago | (#30652814)

There's a pattern to be found in everything provided you cut the logos and labels off your black 501's and never, ever enter a Tommy Hilfiger store.

fabrice BELLARD (1)

Antiocheian (859870) | more than 4 years ago | (#30652822)

Wasn't he the guy who developed lzexe ?

Anyway, what's with surnames spelled in caps ? Does he say "I am fabrice" and then he screams "BELLARD" when stating his name ?

Re:fabrice BELLARD (0)

Anonymous Coward | more than 4 years ago | (#30652944)

Because they understand that, in some cultures (such as the East Asian ones), surnames come first, and given names second. They just coded the information in capitalization.

Re:fabrice BELLARD (-1, Redundant)

Anonymous Coward | more than 4 years ago | (#30653040)

It's a French tradition to do so.

Re:fabrice BELLARD (-1, Redundant)

Anonymous Coward | more than 4 years ago | (#30653042)

its just how the french do it. Kinda makes it easier to work out which is the sirname

Re:fabrice BELLARD (0, Redundant)

AlecC (512609) | more than 4 years ago | (#30653156)

It is just the customary way in France. You see it all the time on French technical sites, and if you get email from French academics. Just a national quirk.

Anyone tried this on Maple? (1, Interesting)

Anonymous Coward | more than 4 years ago | (#30652884)

Has anyone tried to calculate PI to an ungodly precision on Maple/Mathematica/Mathlab/Macsyma/etc.?

I wonder if it is even possible on a computer of this guy's specs?

easy (1)

Tjebbe (36955) | more than 4 years ago | (#30653090)

I have just calculated a digit that's much further. It's 7, and it's somewhere around the 8 trillionth decimal. Give or take a few.

I guess that's a (0)

Dunbal (464142) | more than 4 years ago | (#30653138)

Fundamental difference between pure mathematicians and physicists/engineers. Haven't these people ever heard of significance [wikipedia.org] ? I mean, apart from sheer nerd value, this has absolutely no worth to science or humanity.

So, how do you calculate Pi? Seriously (0)

Anonymous Coward | more than 4 years ago | (#30653252)

Pi = C/d, a circle's circumference divided by its diameter.

So, how do you calculate Pi to X digits?
You can't measure the circle's C and d to X digits (where X is sufficiently large).
You'll eventually hit a significant digits limitation if you try to compute Pi from the standard formula.

So, how do you compute Pi to X digits?

Load More Comments
Slashdot Account

Need an Account?

Forgot your password?

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>
Sign up for Slashdot Newsletters
Create a Slashdot Account

Loading...