## Search found 46 matches

- Thu May 03, 2018 2:38 am UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1988: "Containers"
- Replies:
**17** - Views:
**4978**

### Re: 1988: "Containers"

The Handmade Manifesto. That is all.

- Thu Apr 12, 2018 5:27 am UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1979: "History"
- Replies:
**45** - Views:
**10777**

### Re: 1979: "History"

Think about how much has been written about World War II. How many volumes of text, how many hours of documentary and fictionalised history, how many photographs, how much oral history... Then remember: That was six years of history. In case you've forgotten just how little time six years is, it's t...

- Tue Aug 15, 2017 2:46 am UTC
- Forum: Mathematics
- Topic: Is this a known probability distribution?
- Replies:
**6** - Views:
**4047**

### Re: Is this a known probability distribution?

Have you tried fitting a log-normal distribution? Without knowing anything, my first hypothesis would be that your data follows Gibrat's Law.

- Mon Nov 21, 2016 7:05 am UTC
- Forum: Computer Science
- Topic: Deliberately bad algorithms
- Replies:
**120** - Views:
**53347**

### Re: Deliberately bad algorithms

I don't know if this counts, but the algorithm with the worst complexity that I've ever implemented was Tarski's algorithm for quantifier elimination in real closed fields . To explain what I mean by an algorithm having a bad complexity, here's an explanation: The complexity class O(2^N) is called E...

- Wed Nov 16, 2016 4:22 am UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1757: "November 2016"
- Replies:
**41** - Views:
**9884**

### Re: 1757: "November 2016"

The converse is quite sobering, too: Did you know that you have been around for the majority of [thing]'s existence? 16 - Microsoft Windows 17 - Cabbage Patch Kids 18 - IBM PC 19 - Roller blades 20 - Star Wars 21 - Push-through tabs on drink cans 22 - The Dark Side of the Moon 23 - The World Trade C...

- Mon Jul 11, 2016 10:51 am UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1705: "Pokémon Go"
- Replies:
**57** - Views:
**13379**

### Re: 1705: "Pokémon Go"

Someone tell Simone Giertz. THIS MUST HAPPEN.

- Tue Jul 16, 2013 2:33 am UTC
- Forum: Mathematics
- Topic: what does 'word' mean in hash terminology
- Replies:
**6** - Views:
**1789**

### Re: what does 'word' mean in hash terminology

What phlip said, but if you don't want to follow the link, it's just the number of bytes that the processor in question prefers working with. For 32-bit processors, the word size is 32 bits, or 4 bytes; for 64-bit processors, the word size is 64 bits, or 8 bytes; etc. That's how it works in practic...

- Tue Jul 09, 2013 1:12 am UTC
- Forum: Mathematics
- Topic: Clever High School Math Problems
- Replies:
**31** - Views:
**13450**

### Re: Clever High School Math Problems

One of my favourites: On Saturday, a climber starts at the bottom of a mountain at 9am, and reaches the summit at 5pm. After camping for the night, the climber starts the descent on Sunday at 9am, and reaches the bottom at 5pm. Make no assumptions about the speed of the ascent or descent; in fact, t...

- Mon Jul 08, 2013 2:22 am UTC
- Forum: Mathematics
- Topic: HHH...HHH is unlikely... right?
- Replies:
**11** - Views:
**2796**

### Re: HHH...HHH is unlikely... right?

What if flipping a coin a sufficiently number of times suggested to us that the n'th flip was tails exactly when n is a Fibonacci number? That would be precisely as increasingly unlikely as a coin that turned up heads in the first n flips. Do read the paper that I linked on algorithmic probability;...

- Fri Jul 05, 2013 5:50 am UTC
- Forum: Mathematics
- Topic: HHH...HHH is unlikely... right?
- Replies:
**11** - Views:
**2796**

### Re: HHH...HHH is unlikely... right?

However, it feels intuitively obvious to me that the second sequence is more unlikely, and I know that if you were to count up the number of heads/tails, then counting 20 heads and 0 tails is much more unlikely than one containing 12 heads. I'm neither a Bayesian nor a frequentist. I subscribe to t...

- Fri Jun 21, 2013 4:37 am UTC
- Forum: Science
- Topic: Quantum Computing Uses
- Replies:
**11** - Views:
**4651**

### Re: Quantum Computing Uses

doogly wrote:d wave's successes are in marketing, not computing.

I'd put it differently: The success that D-Wave has had in engineering is grossly overshadowed by over-hype and the fact that Geordie Rose is an irritating and condescending arsehole.

- Fri Jun 21, 2013 3:03 am UTC
- Forum: Science
- Topic: Quantum Computing Uses
- Replies:
**11** - Views:
**4651**

### Re: Quantum Computing Uses

No practical problems have been solved with a quantum computer yet. Very hard to build. That's not quite true. The D-Wave machine appears to solve a subclass of Ising spin glass problem which are hard to write good classical solvers for. This class of problem is practical and useful, which is one o...

- Tue Jun 18, 2013 4:31 am UTC
- Forum: Computer Science
- Topic: Simulating bendy space
- Replies:
**5** - Views:
**4115**

### Re: Simulating bendy space

The language of "bendy space" is differential geometry. You can understand differential geometry as the study of geometric objects on which we can do calculus. Calculus in high-dimensional bendy space looks different from the calculus in Euclidean space that you might be used to, but it's ...

- Thu Jun 13, 2013 4:22 am UTC
- Forum: Mathematics
- Topic: Neat Mental Arithmetic Tricks
- Replies:
**33** - Views:
**5306**

### Re: Neat Mental Arithmetic trickses

Suppose that you want to estimate a division n/d. If you have an approximate reciprocal for d (that is, r is approximately 1/d), then nr is an estimate for n/d, but nr(2-dr) is an even better estimate. Example: Suppose you're estimating 355/113. You know that 1/113 is approximately 0.009. Then: 355 ...

- Wed Jun 12, 2013 2:01 am UTC
- Forum: Computer Science
- Topic: sizeof(data type)
- Replies:
**4** - Views:
**5058**

### Re: sizeof(data type)

sizeof(char) will always be 1 or your compiler is broken; that's mandated by the standard. That's correct, but the catch is that CHAR_BITS need not be 8 according to the standard (though it must be at least 8). If you need guarantees on the size of an integer, use stdint.h. The others can still be ...

- Wed Jun 12, 2013 1:36 am UTC
- Forum: Gaming
- Topic: I need a Game Recommendation
- Replies:
**1559** - Views:
**367961**

### Re: I need a Game Recommendation

I'm looking for some good mobile games for Android. I recommend Plague, Inc. , if you like offbeat strategy. There's a free version. If you like it, I recommend getting the ad-free version but not buying the extras; it's more fun to earn them in the game. I've heard good things about Defender of Te...

- Thu Jun 06, 2013 8:16 am UTC
- Forum: Science
- Topic: Is Quantum Mechanics REALLY "Unintuitive?"
- Replies:
**32** - Views:
**10527**

### Re: Is Quantum Mechanics REALLY "Unintuitive?"

I think maybe you just haven't seen the deeper formalisms of classical mechanics. Yes, I have. If it helps, you can add an "all other things being equal" qualifier. :-) Perhaps the reason why I find QM more intuitive (mathematically speaking) is that I come from an information theory back...

- Thu Jun 06, 2013 4:48 am UTC
- Forum: Computer Science
- Topic: Declaration of value
- Replies:
**5** - Views:
**7076**

### Re: Declaration of value

I want to use the value "age" at a program I have to write in C.... How must the value "age" be declared????As INT or FLOAT???Thank you :) As others have noted, it depends what you're doing with it. However, I should note that real systems never store someone's age, because it c...

- Thu Jun 06, 2013 4:28 am UTC
- Forum: Science
- Topic: Is Quantum Mechanics REALLY "Unintuitive?"
- Replies:
**32** - Views:
**10527**

### Re: Is Quantum Mechanics REALLY "Unintuitive?"

I think that QM is more mathematically intuitive than CM, in the sense that the laws just make more sense. Fields which are algebraically closed (e.g. complex numbers) make more sense than ones which aren't. A system of "probabilities" which obeys a 2-norm makes more sense than one which o...

- Mon May 27, 2013 4:11 am UTC
- Forum: Mathematics
- Topic: n-dimension rotation: Data rotation
- Replies:
**4** - Views:
**2183**

### Re: n-dimension rotation: Data rotation

The assumption is that we have two set of data which have the same data arrangement (i.e. two cloud points that have the same shape. Two almost the same objects which has been translation and rotated) . I am looking for the transformation, which can preserve the ratio of distances between the high-...

- Tue May 21, 2013 12:27 am UTC
- Forum: Coding
- Topic: Sunrise/Sunset
- Replies:
**8** - Views:
**9397**

### Re: Sunrise/Sunset

Yeah, I wrote some code to do this a couple of years ago too, just to see how it's done. I translated it into Java last night. Here it is in all of its glory. Note that my knowledge of java's Date and Calendar stuff dates from pre-1.1 days, so I may not have used this idiomatically. Note that this m...

- Mon May 20, 2013 7:21 am UTC
- Forum: Gaming
- Topic: I need a Game Recommendation
- Replies:
**1559** - Views:
**367961**

### Re: I need a Game Recommendation

If you both like JRPGs and long stories then Tales of Vesperia was a lot of fun. Edit: Also Eternal Sonata. I'll have to consult the other party on the "J" part, but thanks for the suggestions. Incidentally, I've heard that the co-op play in the Fable series is pretty much crap. Can anyon...

- Fri May 17, 2013 5:32 am UTC
- Forum: Gaming
- Topic: I need a Game Recommendation
- Replies:
**1559** - Views:
**367961**

### Re: I need a Game Recommendation

We need a recommendation for a good two-player same-couch co-op game for the XBox 360. We'd prefer something in the fantasy genre, but are open to other suggestions.

EDIT Clarified that it's the 360, not the original.

EDIT Clarified that it's the 360, not the original.

- Thu May 16, 2013 7:01 am UTC
- Forum: Coding
- Topic: How to create my own programming language?
- Replies:
**15** - Views:
**20607**

### Re: How to create my own programming language?

One more thing, while I think of it.

There's lots of decent open source these days. Finding a small but real interpreter (something like Squirrel or Lua would be decent choices these days) and trying to understand it will probably help.

There's lots of decent open source these days. Finding a small but real interpreter (something like Squirrel or Lua would be decent choices these days) and trying to understand it will probably help.

- Thu May 16, 2013 2:19 am UTC
- Forum: Coding
- Topic: How to create my own programming language?
- Replies:
**15** - Views:
**20607**

### Re: How to create my own programming language?

I agree with korona's advice for your first programming language. I'd be tempted to invest in a copy of the dragon book (Aho, Sethi & Ullman's Compilers: Principles, Techniques, and Tools ) or the tiger book (Appel's Modern Compiler Design in C/Java/ML ; the C and Java versions make more sense i...

- Thu May 16, 2013 1:50 am UTC
- Forum: Mathematics
- Topic: triples (x,y,z) with particular properties
- Replies:
**11** - Views:
**4515**

### Re: triples (x,y,z) with particular properties

A comment on your spoiler, which I am posting here not in a spoiler, because it doesn't give anything away: which, I guess, is a well known property of the Fibonacci sequence, tough I have no idea on how to demonstrate it, any hints? You're going to be embarrassed by how obvious this hint is. f(2n) ...

- Fri May 03, 2013 1:55 am UTC
- Forum: Computer Science
- Topic: Loop Unrolling: Suggested Interval?
- Replies:
**9** - Views:
**7568**

### Re: Loop Unrolling: Suggested Interval?

Assuming my code is going to be run on a standard Windows computer that can be purchased at a local computer store (e.g. - 64 bit), would a different interval be more appropriate (6, 7, etc.)? If so, any recommendations? Because this is Fortran code, I'm going to assume that everything is floating ...

- Tue Apr 30, 2013 4:12 am UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1204: "Detail"
- Replies:
**76** - Views:
**15829**

### Re: 1204: "Detail"

I don't see how it would help your case, as I also have a prejudice against Pixar Fair enough. So do I, as it happe.s But anyway, for Pixar, which at the moment had no relation to image acquisition business (as far as I know), They were upstream consumers. This was the days of CAPS , which relied o...

- Sun Apr 28, 2013 9:59 pm UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1204: "Detail"
- Replies:
**76** - Views:
**15829**

### Re: 1204: "Detail"

Then you should probably tell all the imaging sensors manufacturers around the world that they are doing it wrong. As is pointed out in the memo, imaging sensor manufacturers are doing it very much right. Real sensors sample points (sometimes, in colour or other multispectral sensors, there are mul...

- Sun Apr 28, 2013 9:47 pm UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1204: "Detail"
- Replies:
**76** - Views:
**15829**

### Re: 1204: "Detail"

Kit. wrote:Microsoft at its... well, not exactly worst, but you got the idea.

Actually, Alvy Ray Smith wrote the first version of that memo when he was working at Pixar. You might want to rethink your company prejudice.

- Fri Apr 26, 2013 7:24 am UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1201: "Integration by parts"
- Replies:
**81** - Views:
**24470**

### Re: 1201: "Integration by parts"

Your method looks intimidating to me so I imagine it looks intimidating to most students. More or less intimidating than integration by parts, assuming that you didn't already know integration by parts? They key reason why I think that Risch-like methods should be taught instead of integration by p...

- Fri Apr 26, 2013 7:10 am UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1204: "Detail"
- Replies:
**76** - Views:
**15829**

### Re: 1204: "Detail"

Also, the increase in resolution will be limited by the increase in data storage/transfer technology--if your data storage medium could hold one bit per particle, then you would need a storage space the size of the Earth just to map the Earth to the particle level. Ah, but you only need to map the ...

- Fri Apr 26, 2013 4:23 am UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1204: "Detail"
- Replies:
**76** - Views:
**15829**

### Re: 1204: "Detail"

It's basically "how far can you zoom". A resolution of one meter would mean everything within a given 1m square on the ground would show up as just a block of a single color, i.e. one pixel. Repeat after me: A pixel is not a little square. A pixel is not a little square. A pixel is not a ...

- Fri Apr 26, 2013 4:21 am UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1204: "Detail"
- Replies:
**76** - Views:
**15829**

### Re: 1204: "Detail"

In my current job, I work with geographers. Geographers have a saying about Google Earth which goes something like this: Google has undone 400 years of geography by deciding that the Earth is a sphere, because everyone else needs their data to work with Google Earth first, and anything sensible seco...

- Fri Apr 26, 2013 12:05 am UTC
- Forum: Logic Puzzles
- Topic: A very interesting Mathematical Paradox
- Replies:
**387** - Views:
**154976**

### Re: A very interesting Mathematical Paradox

What convinced me (all those many years ago) was this thought experiment: Express the decimal number 0.299999... in base 2. Alternatively, express the (presumably distinct) base-3 numbers 0.12222... and 0.2 in base 10. If 0.999... is not 1, then we have the inevitable conclusion that there are some ...

- Wed Apr 24, 2013 5:45 am UTC
- Forum: Mathematics
- Topic: Module intuition
- Replies:
**7** - Views:
**2749**

### Re: Module intuition

Yeah, I was going to drop the word "torsor", but then I looked at the Wikipedia page for it and thought it might not help.

BTW, John Baez is awesome.

BTW, John Baez is awesome.

- Wed Apr 24, 2013 1:14 am UTC
- Forum: Coding
- Topic: Normal Distribution of Colors
- Replies:
**7** - Views:
**8771**

### Re: Normal Distribution of Colors

This is just a suggestion, but you might want to consider taking a cue from master painters, and use a gamut of the colour wheel . The idea is to work in HSV space, and in particular look at the H-S plane in polar coordinates. Drop a polygon in that space, and choose colours randomly from inside tha...

- Wed Apr 24, 2013 12:33 am UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1201: "Integration by parts"
- Replies:
**81** - Views:
**24470**

### Re: 1201: "Integration by parts"

So, I'm a bit confused at all the comments about it not being easy to teach people what, generally, they should use/identify for this technique. I think that a lot of the trouble is that there is usually some fiddle factor that you need to get exactly right. In this example: ∫ x e^(2x) dx You would...

- Wed Apr 24, 2013 12:12 am UTC
- Forum: Mathematics
- Topic: Module intuition
- Replies:
**7** - Views:
**2749**

### Re: Module intuition

I like the analogy with a group action. If it helps, linear transformations on a vector space form a module, too. (Think about it: linear transformations form a ring, and vectors with addition form an abelian group.) The notion of an "action" (e.g. group action, ring action, module) is pro...

- Mon Apr 22, 2013 7:47 am UTC
- Forum: Logic Puzzles
- Topic: Can you crack my code? Version two
- Replies:
**10** - Views:
**7768**

### Re: Can you crack my code? Version two

First observation is that there are autocorrelation peaks close to that of English text at offsets 6, 10, 13 and 16. If this is a polyalphabetic system with a cycling key, those are the most likely cycle lengths.