Shadow

The dot product of two i-sized vectors [math]\vec{A}[/math], [math]\vec{B}[/math] is defined as [math]\sum_i A_iB_i[/math], What if the vectors aren't equal in dimension? What is the scalar product of [math]\vec{A} = (1, 3, 5)[/math] and [math]\vec{B} = (2, 4)[/math]?

Definitely gonna go see this one uIwiPsgRrOs&NR I though this was pretty fitting

Poor choice of words on my side. No fundamental knowledge base in between. Nothing that you can learn and go "Oh I see" and make your own Photoshop. From a purely coding point of view, ie. what Jill was addressing at the beginning, it's a huge step, but there is nothing fundamentally new; just new techniques, new methods, new ideas, new implementations (and of course all the organization and such), but as you said DH, most of that in principle applies on smaller scales, except that it's so trivial that we don't even notice it. I did read your post, and it did help bring things in perspective. But the main question of this post was if I was missing some fundamental part of programming, something that wasn't mentioned in any of the tutorials I've read, and the answer you all gave me was that there isn't; it's not some big something doing all the work, it's lots of little somethings working together. And that's what's in between.

Thanks a quadrillion DH

Does anybody know of a site (not Wiki, tried that) that gives a comprehensive explanation and solution(s) to the (gravitational) two body problem? Because all the sites so far I've seen are more or less a copy of the Wikipedia article. Thanks

Thanks guys, that helps a lot. It still seems like a mammoth step, but since all of you agreed that there's basically nothing in between, I think it's my perspective that needs adjusting.

I knew about the splitting up part...after all, that's basic problem solving. But I just can't imagine how that's the only difference between them and me. But thanks for the link Cap'n. Also, once they're finished, they just hit "Compile" and than doubleclick on run.exe? And what are all those files around? Most of my executables are just one .exe file and that's it. I realize you have to have sound files, and the high-tech 3D equivalent of sprites and stuff, but it still doesn't account for all the files I don't think...does it? And one last question, when looking at an amount of code as large as for example the Firefox code...where do you start? Where's the friggin' main function?

Okay, this is a little difficult to express, but I'll do my best. I wanted to ask, what's real programming like? As in, how do they do that? I've always wondered how they, I don't know, make Half-Life 2, or Adobe Photoshop...both of those are programmed in C++, yet with what I've learned so far, I just have no clue how they did it. I feel like there's some major something I'm missing. Also, how do they start? Do they just create a new project in their favorite IDE and start coding? Do they even use IDE's for that matter? I've also been fascinated with game mods, specifically those that significantly alter the gameplay. It's obvious that they had to alter part of the game code somehow. How do they do that? I just have Step >X< as learning C++ the way they teach it on the internet, and then suddenly step >Y<, which is stuff like I described above...and I have no clue what's in between. This is lamely written since I'm writing it in a hurry, but I hope it conveys the gist of what I'm trying to ask. Thanks in advance for any light shed on the matter.

Prerequisite #1: Webcam

How do you get a corridor with only one camera? Person A(the pointer) sees person B on his monitor, and nothing else. Person B sees himself in his computer monitor. Nothing else. Or is my imagination faulty? As far as I know, yes, but with the mirrors it's easier since you just see yourself over and over again. But with the webcams, there is nothing to see...

Oh...thanks And if you turn on the cameras facing exactly the screen, what would one see?

I was thinking. If you have two people sitting at their computers with webcams pointed at themselves, they each see the other person on their screen. Then one of them puts the webcam picture on fullscreen, and points his camera at the screen. Person A will see himself on the screen, while person B will still see person A. What happens if person A also switches to full screen, and points his webcam at the screen? Note that I mean in such a way that only the screen is visible in the outgoing signal, no background of the room or something. What do they see? We finally came to the conclusion that you either see what's reflected from the screen, or if for some reason there is 0% reflection you see blackness. Is this correct?

As long as it doesn't develop a will of it's own, why not? Would sort of solve the problem of education...

@Buttacup: I was trying to do it without using msdn, I'm not that familiar with the Windows API yet, which was why I was hoping someone would know of a separate library I could download (eg. a Beep() function that would use external speakers instead of the PC speakers). But this will be good enough, I confess I don't recall coming over it in my searches, but then again I did search for frequency and sound, but never for tone...so that may be it. Thanks @bascule: I'll have a look, thanks for the tip @Pantaz: External speakers.

So will a wall. As I found out today at 6:40 AM.

The discharge was more along the lines of what I was thinking about. He wouldn't be wearing rubber boots,;we would probably be without shirts, with shorts and bare footed. After all, the whole point is to make it zap. And the handle would be made out of some material that doesn't conduct electricity very well. As I was saying, the inside would probably be something like wood, and just to be sure it would be covered with a layer of rubber, which would be the only material that would come in contact with the wielder's hand. If the wielder is stupid enough to touch the blade, well... As for the charge, I would prefer it not jumping through thin air much, if at all possible. As for the jolt delivered, if it'd be painfull enough the make the opponent really try with all his might to defend well (ie. make it as close to a real "lightsaber" fight as possible), it would be great. But I don't know if these two could be combined. As for the charge up method, I have no clue as well. Any suggestions anyone?

Wouldn't it work just if you had current going through the (metal) blade?

http://www.telegraph.co.uk/science/science-news/5921266/Blue-MandMs-mend-spinal-injuries.html The blue pill just keeps getting better...

Me and my friend have gotten into sword dueling...not serious dueling, we just pick up a couple of sticks or something and see who can hit the other first. Anyway, since I've always been a with Star Wars fan, lightsabers have always captured my attention, specifically how to build one. And ever since we started dueling, I was attracted to the possibility of making a training saber. The way I envision it, it would basically be a piece of metal with some kind of voltage going through it, so that it would give a jolt whenever it came in contact with skin. It would certainly make the match more fun, since the opponent would have to guard himself even against the smallest brush. I'm not sure I'm posting in the right section, but I'd like to try an build something like that. Unfortunately, I have absolutely no experience with anything regarding this. So I was wondering if there was someone among you who would be willing to sacrifice time in order to explain step by step how I would build something like that. Before I even start, is something like this even feasible? I realize that playing with electricity isn't all that bright an idea, but with the proper current, is it safe? Or am I out of my mind? When finished, the saber would have two parts; handle and "blade". Here's the first part I know nothing about. Ideally, the blade would be made of a material that would be light and would be able to withstand the force of two blades clashing, which could be quite a force at times. It would also have to conduct electricity. That's most important, otherwise the whole thing would lose it's point. Finally, and probably least important though still an issue, it would be available and not too expensive, which goes by way of saying that carbon nanotubes aren't an option for me. I guess the material I'm talking about would be some kind of metal, but frankly I just have no clue. So that's my first question; what kind of material should I use for the blade? Regardless, the blade would be slightly hollow, so as to accommodate some kind of wire, to transmit the current. I'm going to refrain from asking questions like what kind of wire, how much space in the blade, how do I make that space, etc. That can be, I assume, worked out later. What I'm interested in is how big the current should be. I found a handy picture on a website that showed the reactions to different kinds of currents (http://ehs.okstate.edu/modules/electric/FACES.GIF). According to that website, 3-10 milliamperes is the pain range. More than 10 is the "let go threshold", which seems a little too much to me. So is something like 8 milliamperes what I'm looking for? Is it safe? Can it in any way have more serious effects than a painful jolt? On we go to the handle. The handle would contain the "device", running on batteries, which would create the current. It would have to be made of some kind of material that doesn't conduct electricity well, and would be able to hold the blade in place. I think wood would be good for this, maybe covered with a layer of rubber just to be safe. Now here comes the part that's most confusing to me, since it's the part I have least experience with; how do I make a "device" that generates that kind of current? What batteries would it use? What do I need to make it? Or do I buy it? I'm completely lost here, so be prepared for a lot of dumb questions. This is entirely out of my league. Also, the handle would have some kind of on/off switch, but that would probably be part of the generator. Well, that's that. I've included a rough picture, so it's easier to visualize what I'm visualizing Thanks in advance for any tips.

Consider the polygon in the attachment. It is a regular octagon. In this case, [math]\alpha = \frac{360^o}{8} = 45^o[/math]. In a regular n-gon, [math]\alpha=\frac{360^o}{n}[/math]. This means that [math]\frac{\alpha}{2}=\frac{360^o}{2n}=\frac{180^o}{n}[/math]. Thus, if we wanted to calculate [math]x[/math] on the picture, it would be [math]x = r \cdot sin(\frac{180^o}{n})[/math]. Now consider an n-gon with a radius of one. In such an n-gon, [math]x = sin(\frac{180^o}{n})[/math]. And since [math]y=2 \cdot x[/math], we can easily calculate the perimeter of an regular n-gon: [math] P=2 \cdot n \cdot sin(\frac{180^o}{n})[/math], where [math]P[/math] denotes the perimeter. Now, the bigger n is, the more the n-gon will resemble a circle. Thus, as n approaches infinity, the n-gon will become a circle. So, we can say that [math]\lim_{n\to\infty} 2 \cdot n \cdot r \cdot sin(\frac{180^o}{n}) = 2 \pi r[/math]. In other words, the perimeter of an n-gon with n approaching infinity is equal to the circumference of a circle. Since [math]r=1[/math] we can just ignore the r (even if it didn't equal one they would cancel out), and the twos cancel out, we're left with [math]\lim_{n\to\infty}n \cdot sin(\frac{180^o}{n}) = \pi[/math] And there you go. Hope this helps.

I had an affair with its processor

I searched and couldn't find anything. Any of you know of a statistic of how many passengers (on commercial flights) there are in the air at any given moment? Not just US, the whole world.

Okay, let me rephrase the question; how do you play a sound at a given frequency, for a given duration, but NOT through PC speakers, in C++? I searched the web, couldn't find a thing, so I found myself a tutorial for OpenAl...but I don't even know if OpenAl is capable of that. So, any tips?

Hey all, I was thinking about making a program that would generate a steady sound at a inputted frequency. It would play the frequency at a random time between 0 and x seconds, probably something like ten, from pressing "Start". If you'd hear the frequency, you'd press a button. It's purpose would be to test if you can hear that given frequency. Now, I think I'll manage everything, except the GUI, which I can live without of, and the sound generator. Anybody have any tips? I'm gonna use C++. Cheers, Gabe

Why the hell did you copy my posts?