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Check out this page for more information about necessary and sufficient conditions.

For the record, I take no position about whether running Windows apps is either a necessary or a sufficient condition for the success of Linux on the desktop.

The University of Waikato and Manakau Institute of Technology (in New Zealand) are developing a system called LIDS (Large Interactive Display Surface.) Basically, a LIDS screen is a large pane of glass in a wooden frame with a Mimio on it. Software has been developed by the Uni for various applications.

The most obviously useful application is lecture capture - the LIDS software hooks into Powerpoint and enables a PPT slideshow to be played as usual, but all the annotations and changes on it can be recorded into the document, along with audio. Someone who didn't go to the lecture can then take this PPT file from the web and play back the entire lecture - changes, the lecture delivery, everything that was said and done.

There are 'meeting support' options in LIDS - you can sit a video camera in front of the screen and it will record a silhouette, which gets broadcasted to other stations running the software; on their screen, they see what you see and they see your silhouette as if you were writing on the same screen.

LIDS is a research project, and isn't aimed commercially yet. Lots of usability testing is happening on various aspects of the system at present, in both CSCW (computer-supported collaborative work) and single user aspects.

The most interesting part of the research has been the development of a new metaphor for computer interaction - LIDS works in real space, where multiple people can use it, and interact with it at the same time.

The project doesn't have a web page, but there have been a number of papers submitted to various conferences. A good overview can be found in a paper by Prof. Mark Apperley and Dr. Masood Masoodian from the CS dept at Waikato, which can be found at this link.

I did something similiar a while back (ACK! 6 years alread!) in CMPT 401 (Operating Systems II) at SFU (Simon Fraser University) one of the assignments was to
a) decrypt a RSA encoded message
b) Answer the questions, since the message was an assignment :)

The twist was that there the message didn't use ASCII, but a smaller subset. A table was provided of character set. E and D were small, so that you could brute-force it if you wanted to.

It's not funny, when you decode the message over a weekend, and realize the instructor didn't properly encode the message :)

Definately was a cool assignment, though

Example of RSA
http://world.std.com/~franl/crypto/rsa-example.htm l

I did something similiar a while back (ACK! 6 years alread!) in CMPT 401 (Operating Systems II) at SFU (Simon Fraser University) one of the assignments was to
a) decrypt a RSA encoded message
b) Answer the questions, since the message was an assignment :)

The twist was that there the message didn't use ASCII, but a smaller subset. A table was provided of character set. E and D were small, so that you could brute-force it if you wanted to.

It's not funny, when you decode the message over a weekend, and realize the instructor didn't properly encode the message :)

Definately was a cool assignment, though

Example of RSA
http://world.std.com/~franl/crypto/rsa-example.htm l

You should. Alan Turing is considered by some to be the father of modern Artificial Intelligence. A troubled soul whose contributions to the world included The Turing Test (to measure whether a program is artificially intelligent or not) and cracking the German Enigma cypher code during the war.http://www.math.sfu.ca/histmath/Europe/20thCen turyAD/Turing.html for more info.

My name is [censored], and I'm with [censored], a traditional VC firm. I saw a press release regarding your recent accomplishment ... What particularly interested me was your use of a distributed computing system. This is an area that has been of interest to us at [censored] and we would like to speak with you ... We are currently investing a $1 Billion fund and our typical investment size is $5 to $15 million.

and this non-sentunce is ungramtikal and filled with bad spelled words, but I bet you understand what I am commmunicatin!

Yes, I understand you, and now I understand you to be a moron. That's undoubtedly an unfair assessment, but it's a view you cultivate in that last sentence.

Richard Feynman was scientist and a teacher of science. He used communication skills well - while his science would not have been different without them, his impact would.

Another side of the coin would be Wolfgang Goethe, most heralded and remembered as a poet, but whose work in the area of science was significant as well. To Goethe, literature and science were part of the same whole.

Most people, obviously, aren't Goethe or Feynman. And perhaps I shouldn't bite on trolling like this. But studying literature isn't any more useless than studying calculus - no subject is inherently valuable. What use you make of either one is what's important.

Bringing this back on-topic, my wife is an elementary school teacher. She has an engineering degree and a degree in education. Parents of the children she has taught over the past four years tell me she's great, and I'm not surprised.

The engineering degree doesn't make her a good teacher. The education degree doesn't make her a good teacher. She has math and science aptitude, as well as a passion for reading and history, and those things help. But what helps most of all is that she cares about the kids, and she does what she can to help them individually - to understand their interests, skills, and weaknesses enough to tailor the presentation of the material so they can absorb it.

Those soft skills are what have a "vast impact" on the society around us, because they're what connect those kids with the subjects they're supposed to be learning. Science is useful, and it's one of many things she wishes to teach, but IMO, her "liberal arts" skills are what ensure that the science gets learned.

go here

:: well... if you can find this string - 0123456789 - tell me. cheers, joannou. ::

0123456789 : from 17,387,594,880-th of pi
0123456789 : from 26,852,899,245-th of pi
0123456789 : from 30,243,957,439-th of pi
0123456789 : from 34,549,153,953-th of pi
0123456789 : from 41,952,536,161-th of pi
0123456789 : from 43,289,964,000-th of pi

There was a distributed computing project called PiHex that lasted several years for computing the five trillionth, 40 trillionth, and the quadrillioth bit of Pi, using a variant of the Plouffe discovery, Bellard's formula.

A proof that digits of Pi are random would indeed be news, albeit not exactly a surprise; I'd comment on it but the article's link seems bad or swamped at the moment.

--LP

P.S. Google has a nice list of Pi links.

There was a distributed computing project called PiHex that lasted several years for computing the five trillionth, 40 trillionth, and the quadrillioth bit of Pi, using a variant of the Plouffe discovery, Bellard's formula.

A proof that digits of Pi are random would indeed be news, albeit not exactly a surprise; I'd comment on it but the article's link seems bad or swamped at the moment.

--LP

P.S. Google has a nice list of Pi links.

Nonsense. BY DEFINITION, the threshold of hearing , which is the faintest sound the average person can hear, is zero dB (decibels). 2.5 bells, or 25 decibells, is a sound pressure 10 ^ 2.5, or 316 times as large as the threshold of hearing.

Last semester, I did a directed study about applying approximate machine reasoning to human information access, specifically to searching hypertexts of metadata. One of the ideas I looked at was an article about a search engine called FuzzyBase (pdf) which was developed by three people including my professor, who works in the SFU Communication Networks Laboratory. FuzzyBase did just what you suggest - it used an interactive user session to disambiguate user queries. There are several interesting technologies which use this sort of thing to obtain unambiguous search keys, and most involve the usage of semantic ontologies. If you want to get started looking at this stuff, have a look at some of the articles on this page, especially the online links at the end of the page. There are already search engines that do this to some degree.

Last semester, I did a directed study about applying approximate machine reasoning to human information access, specifically to searching hypertexts of metadata. One of the ideas I looked at was an article about a search engine called FuzzyBase (pdf) which was developed by three people including my professor, who works in the SFU Communication Networks Laboratory. FuzzyBase did just what you suggest - it used an interactive user session to disambiguate user queries. There are several interesting technologies which use this sort of thing to obtain unambiguous search keys, and most involve the usage of semantic ontologies. If you want to get started looking at this stuff, have a look at some of the articles on this page, especially the online links at the end of the page. There are already search engines that do this to some degree.

Last semester, I did a directed study about applying approximate machine reasoning to human information access, specifically to searching hypertexts of metadata. One of the ideas I looked at was an article about a search engine called FuzzyBase (pdf) which was developed by three people including my professor, who works in the SFU Communication Networks Laboratory. FuzzyBase did just what you suggest - it used an interactive user session to disambiguate user queries. There are several interesting technologies which use this sort of thing to obtain unambiguous search keys, and most involve the usage of semantic ontologies. If you want to get started looking at this stuff, have a look at some of the articles on this page, especially the online links at the end of the page. There are already search engines that do this to some degree.

Last semester, I did a directed study about applying approximate machine reasoning to human information access, specifically to searching hypertexts of metadata. One of the ideas I looked at was an article about a search engine called FuzzyBase (pdf) which was developed by three people including my professor, who works in the SFU Communication Networks Laboratory. FuzzyBase did just what you suggest - it used an interactive user session to disambiguate user queries. There are several interesting technologies which use this sort of thing to obtain unambiguous search keys, and most involve the usage of semantic ontologies. If you want to get started looking at this stuff, have a look at some of the articles on this page, especially the online links at the end of the page. There are already search engines that do this to some degree.

__

An old favorite of mine is the 3x+1 problem, variously known as a hailstone function, the Collatz problem, the Syracuse problem, etc:

T(n) = (n % 2 == 0) ? n / 2 : (3 * n + 1) / 2

It is conjectured but not proven that repeated applications of this function eventually reach 1 for all positive integers. Some numbers, e.g. 27, take quite a few steps up and down before they converge. Someone has set up a distributed project by email to look for counterexamples and collect statistics.

Used wast amount of power and computing time in doing so

Beautiful synthesis of "vast" and "wasted." :) Persons who are less interested in math might say that these projects are as wasteful as cracking RC5.

While I can't offer much in the way of ideas, what I would like to do is thank you for bringing this to everyone's attention. For some time now, I have been planning to start a potentially extremely contraversial, slashdot style (probably even slashcode) weblog. One thing that's been stopping me is the cost of doing it out of my pocket. I had been toying with the idea of setting it up at my university, but seeing the problems you've had - well let's just say that that part of the idea is now officially scrapped.

Several people have mentioned the ACLU as a possibility... I remember coming across a group called OpenLaw once upon a time (I think here on Slashdot). They seem to help people in similar situations to yours - maybe it's another avenue to explore.

Best of luck - and keep speaking freely!

The story submitter states:
Do you want to know where OO languages like Java, Ruby, Squeak, and SmallScript come from?

Although it is true that Java is heavily influenced by Smalltalk, there are also distinctive parts of Java that are based on Modula. Most prominent of which are the Exception handling mechanism and threading model based on Monitors.

--

First some background, my home is totally wired. We have some 30 ethernet drops spread throughout the house, all terminating in a central wiring/server closet. Based on this experience, I have a few peices of advice to offer.

1) Always do it right.

By this, I mean don't do anything half-assed just because it's a home installation. This is a mistake I see a lot of people making. Network cable is rather fragile (if you want to maintain 100BaseT capability). This means that running it over the floor, through heating ducts, and what not is generally not a good idea. Plus, running the cable that way is just ugly, and a potential danger. And besides, drywall is easy to patch.

Also, it's incredibly important to document which cable is which. There is nothing more frustrating then trying to figure out which jack/end in one room matches up with which cable down in another room. The easiest way to do this is to come up with a numbering convention for your home, and then mark these numbers on both ends of the cable with some sort of label (Masking tape/pen works fine).

All the cable in our network terminates is laid to cat-5 specifications, and terminates in a proper wall plate on one end, and a patch pannel (see Ours) on the other. This has saved us hours of trying to track down problems, and allows us to quickly bypass problems should one occur. If I were to do our network again, the only change I would make would be to use a 50 pair horizontal cross connect cable to go from our second floor to the wiring closet.

2) Don't underestimate how much cable you need.

The other mistake I see people making is that they underestimate how much cable they need to run to their bedroom, or any other room. Invariably, this leads to chaining hubs, and all sorts of other problems. It's best to pull lots of cable, and if you don't need it right now, just leave it in the walls for future use.

In our place, we pulled 4 lines to each of the bedrooms, and that's barely enough. As it stands, the three of us that live in our home are all using all four drops in each bedroom.

3) Always pull a string.

Whenever you pull cable through floors/ceilings/walls always pull a string along with the cable, and do your best to keep it from getting tangled or twisted around the cable. This string can then be used, in turn, to pull the next cable. When you're done, leave a string in place, in case you suddenly realise you need a nother cable. Your cheap Polyester twine that can be had from Home Depot will be more then adequate.

4) Don't go totally overboard.

Don't spend too much on stuff that you don't need. Cat-5e isn't really worth it, since gigabit can go over properly laid Cat-5, don't lay fiber unless you intend to actually use it, don't buy plenum cable unless your fire code requires it, ect.. Really, always just keep an eye out for the best price/reliability values out there.
This is more important for things like jacks and connectors then for hubs/switches. With a good quality jack, the wires will not come loose. We've been bitten by this more then a few times, and have had to punch things down more often then we'd like.
Hubs and switches, in general, are pretty reliable no matter who makes them. For home use, there really isn't much point in purchasing the latest and greatest 3Com switch, when something less expensive will do the trick. It's highly unlikely that you will need to use all the bells and whistles an expensive one would provide you with.

5) Think Safety.

When opening up walls to pull cable and/or drilling exploratory holes, always be weary of hitting electrical cabling. 120V is not something that you want to hit with a hand saw. Also, be careful if you're up on a ladder. It's very easy to come un-ballanced while doing a hard pull.

6) Add Toys. :)
The last thing to do, once you have a stable platform to work on is to add toys. 802.11 is fun, and incredibly cool, but still much more expensive then a wired solution (as long as you're handy, and can do a reasonable job yourself).

Anyway, I hope this information helps people out with their plans. If there is enough interest, I can put together a list of materials that we used, to give an idea of what works. (Most of our equipment comes from Lin Haw).

I know there is a compiler online for the nes and the snes

There are common assemblers for NES and SNES. NES's 2A03 is a 6502 (same arch as Apple II and C=64) with an on-die sound generator. SNES's 65816 is nearly the same as that of the Apple IIGS. Neither is C-friendly. The 32-bit 68000 in the Sega Genesis, on the other hand, has a version of GCC.

but their cart based so you couldn't just trade them

It's relatively easy to make an EEPROM cartridge for NES; start here. Edit, compile, emulate, edit, compile, emulate, ... burn on to EEPROM, test for bugs tripped up by emu inaccuracies. Just make sure you never use NESticle for testing.

It would be nice if they did opensource their development tools.

Standard "why don't they just free the software" response: For one thing, they might have licensed technology and not licensed the right to sub-license it to the community. (This may be much of why NVIDIA hasn't freed the drivers for its video cards.)

For another thing, game companies sell software. They don't want competition from software designed to run on their older consoles. This is why Nintendo is going after not only ROMs but also emulators, even when such emulators are used to develop free software for old consoles.

Also, there are trademarks and copyrights on the games' content itself. If you have a devkit, you can rip graphics from Mario, Zelda, and Pokemon and use them in your own games.

the great thing about consoles is that the programmers can't just throw in a little extra and say "Oh, they'll upgrade".

But that's exactly what Nintendo did for the Super NES. The programming model for the Super NES CPU and picture generator wasn't that much different from that of the NES. Even though the sound was radically different (NES had 20 registers in CPU address space; Super NES had a mini-DSP in the space of a separate processor with an extremely obscure instruction set), most game publishers just used Nintendo's sound driver from Super Mario World (it was provided with the dev kits). In fact, backwards compatibility with NES games was planned but later dropped.

I've given three hours worth of lectures on the history of computing. That's an entirely different scale than an entire course, but I have some idea.

Swing by your library. There will be more books than you care to read on the history of computing. My school's relatively small library has 31 books.

Some ideas that you'll easily find information for in any history of computers book:

• "ancient" history: the abacus, slide rule, mechanical adder, etc. I've had success photocopying the two parts of a slide rule onto two seperate overhead transparencies. They can be put on the glass and moved around to illustrate their use.
• middle history: Babbage, Jacquard, Hollerith and contemporeries.
• five generations: computer historians have divided up the 20th century into five "generations" of computing. You might organize the course around these.
• history of computational theory: when who discovered what algorithm, etc.

• History of the Internet: nobody thought that was interesting until recently, so it's not in most books.
• History of Games: this will keep them awake. There are a lot of web sites and probably some books.
• Computers in the media: Changing movie portrayals of computers. Find a communications prof or grad who can give you pointers.
• Politics and law surrounding computers.

There are several courses out there.

Finally, talk to your undergrad secretary (or equivalent) and have her put you in contact with textbook publishers. A few quick e-mails that say "I'm looking for a text for a course about..." will land you more books than you know what to do with.

Greg

But when the particle is observed, it is found at a specific place. However, without a _causal_ reason. Admittedly, thats sounds pretty strange.

The following page looks like a reasonably good introduction:
Quantum Primer (http://www.sfu.ca/chemcai/QUANTUM/Quantum_Primer. html)

Quotes of the relevant parts:

"Q13. Exactly what is it that is "waving"?

We pointed out earlier that a wave is a change that varies with location in a periodic, repeating way. What kind of a change do the crests and hollows of a "matter wave" trace out? The answer is that the wave represents the value of a quantity whose square is a measure of the probability of finding the particle in that particular location. In other words, what is "waving" is the value of a mathematical probability function.

Q14. What is the uncertainty principle?

In 1927, Werner Heisenberg proposed that certain pairs of properties of a particle cannot simultaneously have exact values. In particular, the position and the momentum of a particle have associated with them uncertainties x and p given by [...]

As with the de Broglie particle wavelength, this has practical consequences only for electrons and other particles of very small mass. It is very important to understand that these "uncertainties" are not merely limitations related to experimental error or observational technique, but instead they express an underlying fact that Nature does not allow a particle to possess definite values of position and momentum at the same time. This principle (which would be better described by the term "indeterminacy" than "uncertainty") has been thoroughly verified and has far-reaching practical consequences which extend to chemical bonding and molecular structure.

Q15. Is the uncertainty principle consistent with particle waves?

Yes; either one really implies the other. [...]

I hope you aren't planning on taking the computer science program at UBC? I have been informed by my colleagues that SFU's is magnitudes better (I don't know by experience myself; I went to UVic...)

Now, as for UBC Engineering, they're okay - at least they've learned how to suspend VW Beetles off of bridges. :)

I helped out with organizing a student conference/competition one year, and one of the things we needed was a website. Naturally, since we're a student organization, our intent was not to gain profit - just to meet costs. That meant that we didn't have a whole lot of money to splurge on a website (in fact, our budget was already stretched to the limit). A few calls around, and one of the newest ISPs in town had jumped at the opportunity to provide free space for our website. In return, we offered them a spot in our "sponsors" listing, both on the website, and in the conference package.

--

The only thing, based on what I've read on pi, that interests mathemations is trying to determine if pi is completely irrational (can't be expressed as a fraction of two integers) -- if there's any point where the digits in pi repeat ad infinitum, pi becomes rational, and most of the current foundation of advanced number theory will have to be rewritten.

Pi was proved to be irrational in 1770. A later, simpler, proof can be found here.

Something that isn't known about pi is whether or not it is "normal". That is, whether all finite digit sequences of a given length appear with the same frequency in the long run. Based on the tiny initial segment of pi that has been computed (just a few billion digits) pi "seems" to be normal, but initial segments can be misleading.

I tried submitting this when it was news and it got rejected (2000-09-11 12:24:13 The quadrillionth bit of Pi is zero (articles,science) (rejected)).

I guess things have to get into a major newspaper before they are considered newsworthy.

BTW, the original announcement is here.

Colin Percival
Author, PiHex

The official web page of PiHex, the group that originally made this shocking announcement (incidentally it was in early September), is here:

http://www.cecm.sfu.ca/projects/pihex/

Original announce of the algorithm

A page with a lot of info/links

Colin Percival pageThe real info about the PiHex project (Probably in the natinal post article too, but I can't access it)

Cheers,

--fred

Or, as one Tolkein character might say...

Precioussssssss Pi!!!! Givessss meee digitssssssss of Pi!!!!!! Gollum!

There's much more information about this project on its home page at SFU. The guy behind it also has a page there.

M

There's much more information about this project on its home page at SFU. The guy behind it also has a page there.

M

Quicktime movie of hag fish in action

Mechadon is so hot she gives me a w00dy. These pictures are worth a look. And I think the Sick Puppy award should go to Son of Smashy

Mechadon is so hot she gives me a w00dy. These pictures are worth a look. And I think the Sick Puppy award should go to Son of Smashy

Calculate Pi, of course!

Acutally, 3.14156 is wrong. Of the top of my head (really!), it starts 3.14159 26535 89793.

When I was in grade 8, my math teacher put up an overhead once with pi to 10000 digits. I was so blown away I got a photocopy of it. That summer I memorized the first 100 digits, five digits a day. If you do it in groups of five, it's not that hard.

In grades 9-12 I used to write out at least 10 to 15 digits worth when using pi in calculations, especially on math and physics tests. How pathetic of a geek am I, eh?

Over on this Pi site you can get pi to 50 million places, and find out that some guy called Hiroyuki Goto is the current world record holder for the most digits of Pi memorized at over 42000 digits. (!)

Torrey Hoffman (Azog)

Indeed, if you want to model the "less than" relationship for all natural numbers as "1 is less than 2" etc. it is clear the amount of memory required would be infinite. This is quite dumb however, there are formal definitions of the "less than" relationship for natural numbers which can be stated in a few lines.

And this is indeed how it will be done. I don't need all the examples, just some in order to extract the formal relationships such as lessthan. See my posting elsewhere in this discussion tree regarding Radon and image reconstruction from a finite number of projections. If you want it here is the formalsim.

"Kinda knocks BT's patent for hyperlinking out of the water"

1962, huh? Take a look at the Vannevar Bush essay "As We May Think", which appeared in The Atlantic Monthly in July 1945. The technology Bush talks about includes photography and typewriters -- nothing so modern as a "mouse". But those are mere implementation details; the ideas contained in his essay very much resemble the kinds of things we are now doing on the WWW. In fact, in Bush's discussion of users appending an annotating encyclopedia articles, we can see glimpses of Slashdot itself! (Though Bush says nothing about moderation or Anonymous Cowards.) Fascinating reading, and highly recommended.

--Jim

Or, since there might be, oh, say, one or two math geeks out there...

Check out PiHex at http://www.cecm.sfu.ca/projects/pi hex/pihex.html

Calculate pi further and further and further and further...

And yes, they even have a "top producers" thing for you crunchers.

There's also http://www.mersenne.org/ with a list of distributed projects...

POP is IBM's PPC-based reference platform, which will (we hope!) allow OEMs to build inexpensive and clever PPC-based applications. Design files for the first version of POP never came out due to a bad part (the Northbridge, from Winbond); according to Brad, a "POP2" is on its way.

As always, further info is at http://www.openppc.org.

--Tom Geller
Co-founder, The OpenPPC Project

http://www.ktsw.swt.edu/mc3309/hearing. html

http://www.sfu.ca/sca/Manuals/ZAAP f/r/range.html

Here's a bit of technical info on the whole psychoacoustical audio compression thing:
click here

I didn't see any attributions so I'm not sure where the concepts originated from.

As one of the gurus of Pi, he came up with some algorithms himself. Look here.

If any of you are wondering who Jason Haas is, go to the original slashdot story here...also, if youre interested in other stuff about him, go here. It has a bunch of links that tell you about what happened to him

I can hear the yowls from here... "What non-Apple PPC machines?" Right now, there aren't many other than IBM's server line, although you can buy a Sandpoint reference board from Motorola and miscellaneous boards from smaller vendors. (See http://www.openppc.org/vendors.html for a full list.)

But back in August, IBM announced that it would be releasing an open, reference motherboard design for PPC ("POP", or PowerPC Open Platform). The schematics came out quickly, but the whole project's been bogged down in testing because of a faulty northbridge. In the meantime, however, a small community project has sprung up to track POP, at http://www.openppc.org. Interested parties are encouraged to sign up for the mailing list and plumb the Web site for tasty nuggets of goodness.

--Tom Geller
Co-founder, The OpenPPC Project

See The OpenPPC Project to get in touch with the community. The mailing list is essential for those interested in this subject.

IBM has basicly given to any serious takers the full specs for their reference ppc board.

Not yet, they haven't. Because of problems with the Northbridge, they've held off on releasing the all-important Gerber (layout) files. The schematics are there, though.

--Tom Geller
Co-founder, The OpenPPC Project
President, Pop Computers (to build motherboards based on open designs).

Ok. How small can you get a hybrid engine? You know - one of those new ones like they used for the new Honda Insight.

Is it possible to get a version of it small enough to fit in a back pack? Can you silence it?

I'm sure it doesn't have to be completely quiet.

At least not all the time. Just set it up so you can run off of battery some of the time. The problem with that is, DC motors are much larger and heavier. You could always use an AC generator on an engine or turbine. The problem is how?

Maybe you can set up a highly efficientelectrolysis reaction. That would allow you to create Oxygen for breathing and Hydrogen for burning. (I'm hoping that there is a safer way than the Hindenberg for storing H2 now.)

Power is definitely the problem. If that can be solved, I've already been looking into Servos. They can be activated into 2 different configurations - speed and power. Servo amplifiers for speed and servo reducers for power. Not as fast, but a buttload more strength.

Just a few thoughts.

According to this article (c. 1995), Hiroyuki Goto, 21, captured the world record, reciting Pi to over 42,000 decimal places.
I found it linked to from http://www.cecm.sfu.ca/PI/.