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April 19

Password protect webserver

What is the easiest way to password protect an apache webserver, so that websites hosted by that server can only be viewed using a password? bamse (talk) 07:36, 19 April 2012 (UTC)

.htpasswd ¦ Reisio (talk) 14:51, 19 April 2012 (UTC)

Thank you! bamse (talk) 08:12, 20 April 2012 (UTC)

comments in source code

would they slow down interpretation compilation or runtime? especially if there is a lot of comments and speed/efficiency is important. — Preceding unsigned comment added by 203.116.187.1 (talk) 08:14, 19 April 2012 (UTC)

No. The compiler will not include them in any object code. Shadowjams (talk) 08:34, 19 April 2012 (UTC)

I suppose they will probably very slightly slow down compilation, because it takes nonzero time to read them and figure out that they are to be ignored. But it's completely negligible. --Trovatore (talk) 08:41, 19 April 2012 (UTC)

By leaving out comments, particularly for the spurious reason of saving compilation time, you are simply saving up trouble for the future. Imagine someone else coming across your code, years later, long after you left the company, and then having to spend hours going over it just to find out what it is supposed to do. Comments really help the process of understanding what is going on. Astronaut (talk) 11:15, 19 April 2012 (UTC)

I certainly was not advocating leaving out comments! I was just answering the question as asked. --Trovatore (talk) 19:48, 19 April 2012 (UTC)

In the case of Homo Sapiens, you both create a whole field devoted to trying to understand how it works, and another whole field that tries to argue that the source code was intentional. Even a SINGLE comment in the 700 megabytes of uncompressed human genome would have put to rest any question of intelligent design versus evolution. 188.6.94.248 (talk) 12:49, 19 April 2012 (UTC)

You can criticize ID in all sorts of ways, but I'm sorry, this one is pretty silly.

1. We use comments because otherwise we'd forget what a section of code is for. A perfect Designer presumably does not have that limitation. An imperfect designer — say, an alien civilization, might want them though, so:
2. Who says DNA is source code? Seems more like machine code to me. Maybe the source code is somewhere else.
3. Supposing there are comments in the DNA, do you expect them to be in English? There's all sorts of gene sequences with no evident purpose. How do you know those aren't comments?

--Trovatore (talk) 20:17, 19 April 2012 (UTC)

DNA is definitely source code, and there are comments in it in at least one sense. One of the common uses of comments is to "comment out" code that causes problems, and DNA certainly uses mechanisms to do that, including methylation. There may also be comments in the sense of information that functions to provide guidance to external editors, but that's a topic that we don't understand very well yet. Looie496 (talk) 22:14, 19 April 2012 (UTC)

How is it source code? Source code is a human-readable construct used to create machine code, which is what the processor executes. If your point is that there are intermediate steps between the DNA and the proteins, well, processors also have intermediate steps between machine code and the actual switching of voltages. The feature that distinguishes source code from machine code is that source code is supposed to retain the meaning and intent of the algorithm. Where is that in DNA? --Trovatore (talk) 23:52, 19 April 2012 (UTC)

DNA is commonly called a "blueprint" or a "program code" - but these descriptions are merely analogies. Even in the most abstract representations of computation, with very generalized definitions of "computers," there's still a required property: computation. DNA is a molecule; it has a complex behavior. I can even accept the term "molecular machine," albeit with some hesitation. But computer? What, exactly, does DNA "compute"? What algorithm does it execute? I think we are falling down the slippery slope, where any "complicated" behavior can be attributed to "calculation" - which is almost semantically equivalent to attributing it to intelligent design. Complex molecular behaviors - even those that are governed by structural properties of the DNA molecule - are not calculations and are not executing programs. What other complicated natural processes would we also need to call "computers"? Perhaps carnot engines are empirically computing the laws of thermodynamics as they run the "algorithm" of pressure-volume work?

After I composed the above response, I started to wonder: to whom should we attribute this "DNA-is-a-program" analogy? Clearly, some scientist must have been the first to propose that DNA was "machine-like" or even "computer-like." I dug around and found our article about a 1958 quote by none other than Francis Crick. It seems that molecular biologists consider many transcription to be a "program" - but I much prefer to think of it as a process. Now we're really on thin ice - the distinction between an algorithm and a transcription process is sort of blurring in my mind. Still, I do not think that we can safely equate "any sequential information" with "computer program." Again, in computer science, we can define these things abstractly; in a von Neumann computer, sequential data might be a program; but it might not be, depending on its properties (and depending on our definition of "valid program.") One of the most canonical tests is to load the data as program-text into a machine that implements some instruction-set; then to run the program and see if it terminates. And this is, canonically and mathematically provably, an undecidable problem. Nimur (talk) 01:34, 20 April 2012 (UTC)

Sure, the "program" analogy is definitely an imperfect one and can be criticized independently, but my point is, even on the analogy's terms, I don't see that DNA is more like source code than it is like machine code. --Trovatore (talk) 01:40, 20 April 2012 (UTC)

The incredibly (incredibly!) tiny compilation-time cost is outweighed by the fact that programmers who know what's going on code a lot faster. (and more correctly, and write faster code.) Paul (Stansifer) 13:51, 19 April 2012 (UTC)

Agree with the above except that, in many languages, there's a pre-compiler which might strip out the comments before it gets to the compiler. Again, it takes a trivial amount of time to do this. StuRat (talk) 16:46, 19 April 2012 (UTC)

There are interpreters that literally interpret the program source code, comments and all. In those, the overhead of repeatedly skipping a comment in an inner loop could be significant. Applesoft BASIC is one example I have personal experience with. To get a little bit of extra speed, people would remove comments, use single-letter variable names, put the speed-sensitive code at the beginning (because the interpreter always searched for line numbers from the beginning on every GOTO or GOSUB), and so on. But all popular "interpreters" these days actually compile to bytecode (removing comments in the process) and then interpret the bytecode. -- BenRG (talk) 21:34, 20 April 2012 (UTC)

You are right about interpreted BASIC. And programmers would leave out spaces when possible, because that slowed it down. Also, even putting more than one line of code per physical line, seperated by colons, when the language supported it. Bubba73 ^{You talkin' to me?} 04:41, 22 April 2012 (UTC)

google advanced search

I can't see the advanced search option in the opening goggle page. Does it happening to everyone? --SupernovaExplosion ^Talk 09:47, 19 April 2012 (UTC)

Seems to have gone. Do your search first and on the results page you should see a cogwheel top right. Click on that and select "advanced search".--Shantavira|^{feed me} 12:20, 19 April 2012 (UTC)

That is unfortunate. They have removed a vital feature which could be previously used with ease. --SupernovaExplosion ^Talk 15:48, 19 April 2012 (UTC)

Agreed. I'll mark this resolved, since Shantavira gave you the workaround. StuRat (talk) 16:38, 19 April 2012 (UTC)

Resolved

In Internet Explorer, I've bookmarked http://www.google.com/?complete=0 with the name Google. Then I can enter google in the address box to go to that page. The page doesn't use auto complete and still has the gear at the top with Advanced Search. --Bavi H (talk) 23:50, 19 April 2012 (UTC)

Google Advanced Search hasn't been removed - it can be accessed directly at http://www.google.com/advanced_search Vickreman.Chettiar 03:09, 22 April 2012 (UTC)

What is the best program to let me run Windows programs in Ubuntu 11.10?

I've heard of WINE but it doesn't work too well... is there a better alternative, regardless of price? — Preceding unsigned comment added by 157.233.12.74 (talk) 16:44, 19 April 2012 (UTC)

Well, any attempt to emulate another O/S within yours is bound to have lots of overhead. So, while you might find one which works better, it's still going to be slower than running directly on Windows. A dual boot system might work better, if you have lots of need for both O/S's. StuRat (talk) 16:50, 19 April 2012 (UTC)

IMO, the best alternative is VMWare Workstation. It's a bit slower than the native machine, but the compatibility is perfect. --Sean 16:58, 19 April 2012 (UTC)

I'd have to say KVM (Linux's own built-in virtualization solution) or VirtualBox (slightly more user-friendly than KVM at the moment) would both be better choices for virtualizing a Windows guest on a Linux host. VMware, unlike KVM and VirtualBox, is not free / open source, and consequently always going to be more of a pain to use on the average Linux distro.
I agree with StuRat's assessment, but with a computer from the last few years you should be fine virtualizing most things, with the exception of graphics intense (that is, popular :p) games, for which you probably will want to dual boot. ¦ Reisio (talk) 17:41, 19 April 2012 (UTC)

If you're trying to play a game, Play On Linux is very good. It is based on Wine, but has a huge database of games and sets Wine up properly for each game. Worth a try if you have had a bad experience using Wine for gaming. - Cucumber Mike (talk) 18:03, 19 April 2012 (UTC)

if you are going to use Ubuntu, don't forget to add the more up to date wine repository: [1]. IRWolfie- (talk) 20:21, 19 April 2012 (UTC)

Tearing off a Firefox tab

I managed to do this accidentally in Firefox 11.0, but don't know how I did it. So, how do I take an existing Firefox tab, and move it into a new Firefox window ? StuRat (talk) 17:45, 19 April 2012 (UTC)

In FF11.0 for Ubuntu, I simply left-click-and-hold on the tab in question, drag down about an inch, then release. Et voila! - Cucumber Mike (talk) 18:00, 19 April 2012 (UTC)

This is in Windows XP, but I'll try that, thanks. StuRat (talk) 19:18, 19 April 2012 (UTC)

It works on Snow Leopard too. —Tamfang (talk) 22:40, 19 April 2012 (UTC)

Does it work in IE ? StuRat (talk) 06:19, 20 April 2012 (UTC)

Who cares? —Tamfang (talk) 08:30, 24 April 2012 (UTC)

Laptop will not connect to particular WiFi network

Hello, I purchased an HP laptop last Christmas, and regularly connected to my school's wifi network. However, recently, neither the school's unencrypted "outsider" network, nor the encrypted (unfortunately I can't remember what kind) "insider" network, will appear as networks to connect to. Oddly, I see all other wireless networks, including several Texas Instruments Navigator Access Points). I normally tether my laptop through my phone, but after around twenty minutes, the "outsider" network appeaars, but I am unable to connect to it. My phone, and everyone else's laptops, can connect easily to either network. Any ideas as to why this occurs or how to fix it?

Thanks, 99.224.72.42 (talk) 21:22, 19 April 2012 (UTC)

Opening txt files in IE

Hi, i use IE to read txt files like stuff from Gutenburg. Most display just fine but every once in a while the file doesn't wrap the text but displays each paragraph as one line that must be scrolled across to view. Any idea why this is and what I can do to force the text to wrap? Thanks! — Preceding unsigned comment added by 148.66.156.178 (talk) 21:50, 19 April 2012 (UTC)

It is probably because those txt files don't contain carriage returns. Why don't you use the html versions, which are much more suitable for a web browser? Looie496 (talk) 22:03, 19 April 2012 (UTC)

Thanks for the answer! I have gone back and dl'd the html versions for some but I have other files (not Gutenburg) where there is no html version so was wondering if there was an easy fix. I can copypaste the txt file to Word, then save as a txt file and it views correctly so I can work around the problem but was wondering if there was an IE setting that would force text wrap or limit the horizontal size of the page. — Preceding unsigned comment added by 148.66.156.178 (talk) 22:32, 19 April 2012 (UTC)

Some text files have CRs (Carriage Returns) and others have LFs (Line Feeds). You need to find some setting to the effect of "Interpret LFs as CRs" to fix the problem, but I don't know if IE has such a setting. StuRat (talk) 06:18, 20 April 2012 (UTC)

Some text files don't use either CRs or LFs within paragraphs, leaving the display program to do line-wrapping. That's most likely to be the case here. Looie496 (talk) 23:44, 20 April 2012 (UTC)

April 20

What sized go-board could a Matrioshka brain solve in a few days?

Go, the game 1001 x 1001? a million and 1 x a million and 1? Am I horribly wrong? What about 100 years?

Yes. You're horribly wrong ;). Consider Go in the context of the Bremermann's limit, as described at Transcomputational_problem#Implications: "Problems involving vast numbers of possibilities will not be solved by sheer data processing quantity." --Tagishsimon (talk) 00:09, 20 April 2012 (UTC)

(edit conflict) Assuming you're talking about brute force, probably 8x8 or less. According to Go and mathematics, there are around $10^{38}$ legal positions in a 9x9 game. There are something like $10^{80}$ atoms in the universe, and a single Matrioshka brain is only a small part of the universe. Working out any actual numbers would require figuring out how generous we're willing to be with Moore's Law, but my gut says that 9x9 is going to be physically impossible in 100 years, no matter what. Paul (Stansifer) 00:31, 20 April 2012 (UTC)

Please don't conflate "universe" with "observable universe". --Trovatore (talk) 00:39, 20 April 2012 (UTC)

Matrioshka brain is so speculative as to be more on the level of a sci-fi thought experiment. Apart from the generalized computational infferences we can make, such as the above answers, asking specific questions about what it can or can't do in a specific timeframe is meaningless. Vespine (talk) 01:37, 20 April 2012 (UTC)

So quantum computing won't help this, right? Why does it work on cracking password keys though? (Or at least it might, if we can figure out how to make it work) Sagittarian Milky Way (talk) 21:22, 21 April 2012 (UTC)

Quantum computers run quantum algorithms. There are fast quantum algorithms for cracking all of the popular public-key cryptography systems and certain other problems, but for most problems the fastest known quantum algorithm is as slow as the fastest known classical algorithm. I wouldn't rule out the possibility that quantum computers could provide some sort of insight into games like Go, but you would have to develop quantum algorithms for that. You can't automatically make an analysis go faster by running it on a quantum computer. -- BenRG (talk) 16:44, 22 April 2012 (UTC)

C++

I want to learn how to code preferably in C++, have no clue how to start. I Think I am supposed to learn C first If i'm not mistaken. Any advice to get going to help kickstart my passion? — Preceding unsigned comment added by Darkspartan4121 (talk • contribs) 01:13, 20 April 2012 (UTC)

http://www.parashift.com/c++-faq-lite/how-to-learn-cpp.html ¦ Reisio (talk) 03:06, 20 April 2012 (UTC)

It is unfair to send a novice to the C++ FAQs without also linking to the C++ FQAs. Unfortunately, most of the frequently questioned answers will only make sense after many years of software experience. Nimur (talk) 05:05, 20 April 2012 (UTC)

You could try javascript... (But would be only for webpages)190.158.212.204 (talk) 03:19, 20 April 2012 (UTC)

If you've never programmed before, It's by no means a "consensus" but I've heard a lot of people recommend to start with Python. Vespine (talk) 03:29, 20 April 2012 (UTC)

I have two suggestions. (1) Buy a book, it probably doesn't matter that much which one, they all cover the same ground. (2) Install Linux on your computer -- it provides a much more supportive environment than Windows. I personally think C is a better language than C++, but you might as well learn whichever one you intend to use. Looie496 (talk) 04:23, 20 April 2012 (UTC)

I highly recommend The C Programming Language. If you choose to learn C++, I highly recommend The C++ Programming Language. These books are better than most other books, including those "quick start tutorial style" books, because learning to program isn't a process to rush through. Just to reduce your confusion: you do not need to learn C before learning C++. The two languages are related, historically; but it is not necessary to learn C prior to learning C++. Most C++ programmers can read and understand most C programs. The reciprocal is not always true, because C++ adds so many language constructs that do not exist in C; but I contend that neither C nor C++ programmers can understand most C++ programs. I also recommend learning Linux or Unix (or a Unix derivative); these operating systems are designed to help programmers and computers cooperate; many other operating systems are designed to improve usability for non-programmers at the expense of increasing programmer effort.

Keep this concept clear: you are undertaking several different tasks. You are learning how to program, which requires learning some mathematical formalism and structured, logical thought processing. You are also learning some basic computer architecture, which will require a bit of detailed theoretical and practical knowledge about your machine. (Because you have chosen C or C++, languages that intentionally expose programmers to the machine's inner workings, you will need to learn these concepts and details well). And finally, you are also learning the syntax and structure, as well as the stylistic conventions, of a particular language (C or C++). These tasks can interfere with each other; when you hit some early bugs, it will be hard to know if you've got a logic bug, a syntax error, or maybe your linker isn't doing what you believe it should be doing. Unlike some other languages (Python, mentioned above; or perl, or Java...), C and C++ are harder for novices because they really require you (the programmer) to determine whether your bug is due to an error in logic, syntax, or engineering-practical-details Use tabs, not spaces, in your Makefiles; and don't skimp on studying linker precedence rules, because "symbol not found" is a useless unhelpful error message for a novice!. As a novice, this is difficult; so many prefer to start with easier languages and develop experience. However, C is a great first language; it's like learning to fly a Cub. You will need to learn to do it correctly, or it won't work at all. Later, when you transition to other projects with complex engineering needs, you will already have sharp skills and good techniques. Nimur (talk) 05:05, 20 April 2012 (UTC)

<off-topic>They require you to determine whether your bug is due to an error in logic or syntax. Maybe that's because (IIRC) C/C++ is context-dependent? while other languages are not (e.g. Java, IIRC again) --151.75.56.185 (talk) 15:43, 20 April 2012 (UTC)</off-topic>

Having programmed in C++, I can confirm that the complaints presented in Nimur's link above about the language are 100% correct. C++ is the most unwieldy third-generation programming language I've ever used. So it depends on the reason you're learning to code: if it's to gain a general understanding of what coding is about and its ins-and-outs, I suggest starting with C++, just because it will force you to do the mundane things that other languages do automatically. Otherwise, you might be better off choosing another language. Magog the Ogre (talk) 11:51, 21 April 2012 (UTC)

Legitimate or pirated copy

How do I know if this video is legitimate or a pirated copy? I'd rather buy the product if I would be watching it illegitimately. 98.235.166.47 (talk) 09:51, 20 April 2012 (UTC)

You can't really know without contacting the BBC or the Discovery Channel, but I've never heard of either of these organizations relinquishing copyright; and if they'd made it available for free online viewing it would not be at such a reduced quality, and probably not split up either. ¦ Reisio (talk) 22:41, 20 April 2012 (UTC)

I'm not arguing just for the sake of arguing, but I see quite a bit of both pirated and legitimate BBC stuff here: [2]. And that documentary is almost 20 years old; video from that era is often degraded. 98.235.166.47 (talk) 07:18, 21 April 2012 (UTC)

CQuote

Resolved

I want to use the CQuote template on a wordpress site. How would I go about doing it? --Drogonov 10:35, 20 April 2012 (UTC)

With this CSS…

blockquote {
	position: relative;
	padding: 0 40px;
}
blockquote:before, 
blockquote:after {
	position: absolute;
	font: bold 35px 'times new roman', serif;
	color: #b2b7f2;
}
blockquote:before {
	content: '“';
	left: 0;
	top: 0;
	line-height: 30px;
}
blockquote:after {
	content: '”';
	right: 0;
	bottom: 0;
	line-height: 5px;
}
blockquote + p {
	font-size: small;
	text-align: right;
	padding: 0 4% 0 0;
}

…and this HTML…

<blockquote>
	<p>Terrorism is the war of the poor, and war is the terrorism of the rich.</p>
</blockquote>
<p>— Peter Ustinov</p>

¦ Reisio (talk) 23:37, 20 April 2012 (UTC)

Thanks that's helpful. If I don't want it to overide the normal blockquote behaviour I have to define it as a class, is that right? Or can I replace blockquote with "cquote" in your above CSS? And then use <cquote> ... </cquote> (I doubt this will work) --Drogonov 07:40, 21 April 2012 (UTC)

Yes, the former (using a class) is the proper way to do it. Regards, - Jarry1250 ^{[Deliberation needed]} 13:09, 21 April 2012 (UTC)

Indeed, you could just replace instances of blockquote in the CSS given with blockquote.cquote and <blockquote> in the HTML given with <blockquote class="cquote"> (to be absolutely clear :p). ¦ Reisio (talk) 17:22, 21 April 2012 (UTC)

javascript

Resolved

In an earlier question I asked how to open links containing &number= into tabs in Firefox using greasemonkey javascript, and the solution worked perfectly. However, I now need to do exactly the same thing except leave out links containing #. For example, I want to open http://example.com/&number=12 but not http://example.com/&number=12#top. The code I have right now is as follows;

var elems = document.getElementsByTagName("a");
for (var e in elems) {
    var s = elems[e].href;
    if (s.indexOf("&number=") !== -1) {
        GM_openInTab(s);
    }
}

82.45.62.107 (talk) 15:29, 20 April 2012 (UTC)

if (s.indexOf("&number=") !== -1 && s.indexOf("#") === -1) {

--151.75.56.185 (talk) 15:40, 20 April 2012 (UTC)

Thanks! 82.45.62.107 (talk) 10:28, 21 April 2012 (UTC)

How do I save a screen shot?

Resolved

I have the email ready to attach it and I have pressed "Prt Scr". I have Windows Vista.— Vchimpanzee · talk · contributions · 19:13, 20 April 2012 (UTC)

Easiest way is to open Microsoft Paint, then paste, then save. - Jarry1250 ^{[Deliberation needed]} 19:17, 20 April 2012 (UTC)

Done, thanks.— Vchimpanzee · talk · contributions · 19:30, 20 April 2012 (UTC)

See also Snipping Tool. ¦ Reisio (talk) 22:42, 20 April 2012 (UTC)

If you just want a screen shot of the active application, Alt-PrtScrn does this.--Phil Holmes (talk) 11:29, 21 April 2012 (UTC)

Dafualt Theme font (Office 2010)

In office 2010 (MS Word), I noticed that the default theme font is calibri and its size is 11. I want to change it permanently to "times new roman" along with font size 12 whenever I open MS office 2010. I tried to make this change in font dialog box, but apparently failed. Is there any way to do that? Thanks in advance--NAHID 21:48, 20 April 2012 (UTC)

Usually with Word what you want to do is change the "Normal" style (the default text style upon which most others are based) within the file "Normal.dot" (the default template) which is hidden somewhere in your MS Word directories (use your file search to find it). --Mr.98 (talk) 04:08, 21 April 2012 (UTC)

An easier way... right click and choose "Font..." and you should see something like the this font dialog (I presume Word 2010 is similar enough to Work 2007 for the dialog to be almost the same). Change to Times New Roman, 12 point. Click the "Default..." button on the bottom left. Astronaut (talk) 13:40, 21 April 2012 (UTC)

• Thanks. It worked in 2010 too.--NAHID 19:51, 21 April 2012 (UTC)

April 21

LZMA2 Data Compression - PCIe ASIC

  I'm looking for a PCIe card with an ASIC for LZMA2 Data Compression. Do such cards currently exist, and which manufacturers make them? Vickreman.Chettiar 03:24, 21 April 2012 (UTC)

There are certainly chips for that. I don't know about pcie boards around them. Try hifn.com for possibilities. 64.160.39.210 (talk) 08:54, 23 April 2012 (UTC)

Zedo

Zedo is an ad serving tech company. The article pans it for being "spyware". The real problem (from my personal opinion and any quick Internet search) is that it is annoying. However, it is hard to sift through standard search results since everything about the company is from nonRS forum's or the company itself (primary). Has anyone seen anything from a neutral RS simly stating "people feel x about Zedo"?

Disclaimer: I have made fun of Jimbo for his efforts on this article even though I do agree that "spyware" is a little extreme.Cptnono (talk) 04:58, 21 April 2012 (UTC)

What are the disadvantages of object-oriented programming?

Compared to other paradigms such as functional programming? — Preceding unsigned comment added by 220.255.1.71 (talk) 05:14, 21 April 2012 (UTC)

If you told us what was wrong with the 2 million + hits you get if you google "disadvantages of object-oriented programming", we could tailor our answers to your needs. Henry^Flower 13:58, 21 April 2012 (UTC)

It requires the programmer to model something, rather than allowing the programmer to just do something. If the programmer is any smart, they realize that modelling something becomes very useful, very, very fast. But if they're just in a hurry, know exactly what steps they want a computer to do, and don't have complex data that they want to pigeonhole into an object hierarchy, then an object-oriented approach could be a disadvantage. 188.6.94.248 (talk) 14:52, 21 April 2012 (UTC)

Do you mean object-oriented programming as usually practiced in industry (e.g. Java, C#, C++, etc.), or object-oriented programming in theory (e.g. Smalltalk)? They're pretty different from each other, in part because the designs of industry languages are often bogged down with performance concerns. Paul (Stansifer) 15:52, 21 April 2012 (UTC)

Since it's a major change, involving a lot or retraining of programmers and rewriting of code, the question comes up of whether the benefits justify such a large investment. For comparison, look at Blu-Ray versus standard-def DVDs. Yes, Blu-Ray is better. But, is it enough better to justify scrapping all your current DVDs and DVD players to upgrade it all to Blu-Ray ? Most people don't think so. StuRat (talk) 16:33, 21 April 2012 (UTC)

Most programmers are already used to OO programming (starting with C++ and Delphi ages ago). My experience is that rewriting code from scratch every now and then (like every 4 years) actually saves costs when compared to maintaining old code. My company has a pretty huge software package containing well over 500k lines of code and redesigning its modules from scratch instead of hacking new features into them is 80% of what we do (leaving 20% for fixing smaller bugs). Joepnl (talk) 21:21, 24 April 2012 (UTC)

That approach just isn't possible in many industries, with huge volumes of legacy code. Rewriting that every 4 years would require 10x the staff they have on hand. StuRat (talk) 16:11, 25 April 2012 (UTC)

Syncing Firefox add-on data

I use two different Firefox installations on a regular basis (three if you count my smartphone). So I've installed Firefox Sync, which did a great job of synchronizing my: cookies, bookmarks, history, and list of add-ons. However, it did not copy the data within the add-ons themselves between my installations, which means my I cannot use StumbleUpon without goofing up my counter, I cannot sync my NoScript data, my Adblock Plus data is not synchronized (which is obnoxious because I have data in there about blocking Facebook because I don't want them tracking me everywhere tyvm), my customized AutoPager data is no good, and I have to login all over again for TinEye. Is there a way to automatically sync this data between installations? Magog the Ogre (talk) 07:30, 21 April 2012 (UTC)

You can simply copy the contents of your profile directory into another profile directory and basically have the same everything, as for actually syncing these... a dynamic solution would probably be overkill, you could probably just replace your Firefox shortcut with one that first transfers the data over a network and then starts Firefox (or any number of scheduled transfer solutions you like). If all the installations are on the same local network (and therefore have virtually no latency reaching one another), you could just have one installation and mount it over the network for the other two, eliminating the need to deliberately sync altogether. ¦ Reisio (talk) 17:28, 21 April 2012 (UTC)

Download page with wget

Resolved

I'm trying to save this url with wget using the --page-requisites function. The webpage is downloaded correctly, as are the css and banners, but the image thumbnails are not. I have tried everything I can think of and it simply will not downloaded the image thumbnails (for example, http://desuchan.net/desu/thumb/1231032526187s.jpg). I experience the exact same problem using httrack as well, so this does not appear to be a wget specific error. Does anyone have any idea why it is failing like this? The page appears to display perfectly in Firefox, IE, and Opera. It's driving me crazy ComputerQuestion (talk) 12:23, 21 April 2012 (UTC)

What thumbnails? When I visited that URL I saw no thumbnails - just a banner. I use IE 9. Astronaut (talk) 13:50, 21 April 2012 (UTC)

This is how it looks in Firefox. I've highlighted the thumbnails in red boxes. Why does it display differently on IE 9? Could this be why wget is unable to download the page properly? ComputerQuestion (talk) 14:33, 21 April 2012 (UTC)

Try HTTrack, maybe? ¦ Reisio (talk) 17:35, 21 April 2012 (UTC)

"I experience the exact same problem using httrack as well, so this does not appear to be a wget specific error." ComputerQuestion (talk) 18:17, 21 April 2012 (UTC)

Sorry. That is odd. In the interim you could just scrape them out (curl | grep). ¦ Reisio (talk) 18:58, 21 April 2012 (UTC)

It looks like the main part of the page appears within an HTML comment <!-- -->, perhaps by accident. The problem comment starts with <div class="globalannounce"><!--. A little bit later there's a --!> (note the incorrect !), which seems to be the intended end of that comment. On my computer, Firefox and Chrome interpret this as the end of the HTML comment, but Internet Explorer and Opera keep going until they get to --> <a href="http://validator.w3.org/check?uri=referer">, which is near the end of the page. Wget and HTTrack are probably also obeying the correct HTML comment markers and missing the main part of the page. --Bavi H (talk) 19:17, 21 April 2012 (UTC)

(Ha ha. If you actually click on the W3C validator icon at the bottom of that page, it tells you the same thing. I might have saved a lot of debugging time trying that first!) --Bavi H (talk) 19:26, 21 April 2012 (UTC)

Piping through tidy could possibly help you automate it in such a case. ¦ Reisio (talk) 19:46, 21 April 2012 (UTC)

Mystery solved, thanks everyone ComputerQuestion (talk) 20:13, 21 April 2012 (UTC)

Changing a laptop case cover

I am not very good with computers, but I have a cracked cover/lid on my HP Pavillion. I found a replacement on ebay. Now, how do I change them out. I see a series of screws around the screen side, so I assume I need to take them out. Is there anything I need to be aware of before proceeding with this. Thanks. — Preceding unsigned comment added by Azcatlv (talk • contribs) 20:48, 21 April 2012 (UTC)

I strongly recommend getting hold of the workshop manual relating to your specific laptop model. A quick Google suggests that these are freely available. The screen is usually surrounded by all sorts of ancillary bits and pieces such as WiFi antennae, microphones, cameras etc. and their associated wiring. Normally, these are attached to the outer surface of the lid so the screws you see just hold the bezel round the screen in place.86.168.2.185 (talk) 21:43, 21 April 2012 (UTC)

One warning is that the guts of a laptop tend to be far more fragile than a desktop. So, separate the lid very slowly, watching the inside as you open it, and stop if you feel even a little resistance. StuRat (talk) 21:50, 21 April 2012 (UTC)

Unfortunately, modern consumer electronics have something in common with the TARDIS: They are bigger on the inside than on the outside. I recently tried to clean the inside of my camera, and had trouble putting it back together even though the only thing I removed before giving up was the back cover. --Stephan Schulz (talk) 23:12, 21 April 2012 (UTC)

Populate a MySQL database automatically

I have that website (PHP, MySQL,...) which also includes an interface to populate the database (uploading images, text, pdf files,..). This is fine, if I want to upload a couple of items, however for large amounts of data it is a bit tiresome, so I would like to automate this task. What is the best way to do that? For instance I could imagine to drop all files (jpg, pdf, txt) that belong together in a directory, and just to run a script that uploads the files, extracts the information from the txt files and puts them in their proper place in the database. Are there some tools which would help me in creating such scripts or am I on my own? bamse (talk) 21:02, 21 April 2012 (UTC)

It really depends on the exact setup of the database; I doubt there is anything out there that can do this sort of thing automatically. (I assume by "that website" you mean phpMyAdmin?) Are you really storing JPEGs and other binary data in the database as data? That is a somewhat problematic way to use the database and unnecessarily taxing (usually you don't store actually images in the database, you store a link to the image and have the image uploaded to the server). --Mr.98 (talk) 21:44, 21 April 2012 (UTC)

By "that website" I did mean a website (in this case a sales portal which has images of items, descriptions of items, etc. stored in a database). I do use phpmyadmin to administrate the database though as I know virtually nothing about MySQL syntax. That's why I was looking for an automatic way, kind of like a "batch phpmyadmin". And yes, the images are not directly stored in the database, but they are located in an image folder and links to the images are stored in the database. So the script/tool I am looking for should copy images to that image directory and write the links into the database among others. Would probably be a good idea to check whether images with the same filename already exist, before overwriting them. bamse (talk) 07:35, 22 April 2012 (UTC)

OK, that clarifies things a bit. One possibility would be to make something like an Excel file of all of the data and import it via phpMyAdmin directly, skipping the interface. In my experience this is a lot faster than doing it all through interfaces. --Mr.98 (talk) 14:38, 22 April 2012 (UTC)

Thanks, will check out the excel import. Does it allow to import to several tables at once? bamse (talk)

There are commands you can use programmatically, too. ¦ Reisio (talk) 16:35, 22 April 2012 (UTC)

Do you mean SQL scripts or something else? bamse (talk) 12:08, 24 April 2012 (UTC)

Slow laptop/ task manager

Resolved

For about a month, our Windows 7 laptop was very slow. Yesterday I looked under Task Manager, the CPU column of the Processes tab, and it was showing that usually less than 5% of the CPU was being used, adding all of the processes. However, the Performance tab showed 60-70% CPU usage. I ran the full scan of Microsoft Safety Scanner and it removed three things. Then I rebooted and now it is OK.

But my question is: how can something be using up that much of the CPU according to the Performance tab, yet not show up in the Processes tab? Bubba73 ^{You talkin' to me?} 21:21, 21 April 2012 (UTC)

Bad programming? Did you check the box at the bottom that said 'show processes from all users'? ¦ Reisio (talk) 23:12, 21 April 2012 (UTC)

There are ways for evil programs to hide themselves from Task Manager. Looie496 (talk) 00:03, 22 April 2012 (UTC)

Unfortunately, the "all users" was not checked on the laptop (it is checked on my desktops). I wish it had been on so maybe I could have seen what was causing the problem. Bubba73 ^{You talkin' to me?} 01:53, 22 April 2012 (UTC)

Malware can disguise itself as an innocuous process, but can't hide CPU usage (not that I'm aware of, anyway). -- BenRG (talk) 03:59, 22 April 2012 (UTC)

Well, the obvious way for malware to hide CPU usage is to replace Task Manager with a hacked version. I'm not expert enough in Windows to know if there is a less intrusive way of doing it. Looie496 (talk) 17:48, 22 April 2012 (UTC)

I know this doesn't answer your question, but under normal usage (i.e., not scientific computing), processor usage has very little relationship with perceived speed. Memory size and memory usage control the degree to which the machine is swapping, which does have a huge effect on performance. Of course, the processes that were taking up lots of CPU may have also been taking up lots of memory. Paul (Stansifer) 05:14, 22 April 2012 (UTC)

The memory use was not particularly high - only the CPU usage. Bubba73 ^{You talkin' to me?} 15:27, 22 April 2012 (UTC)

Mac malware

I never used to worry about viruses or malware with my mac, and truthfully I haven't noticed any problems but I have seen lately in a few disparate places that macs more and more are subject to infections, even if nowhere on the scale of PCs. Are there any free programs anyone recommends I run to see if I have anything and/or something that I should have running in the background? Or is what I've read bunk?--108.54.17.230 (talk) 22:51, 21 April 2012 (UTC)

Comparison of antivirus software, wouldn't worry about it too much. ¦ Reisio (talk) 23:11, 21 April 2012 (UTC)

Great page. I guess I'll try avast! Thanks — Preceding unsigned comment added by 108.54.17.230 (talk) 02:48, 22 April 2012 (UTC)

To clarify, a decent antivirus app won't bog down your computer (even the free versions, usually), and even if you personally aren't ever at risk of something nasty, it can help to protect Windows users from files you might redistribute. A lot of antivirus software providers will tell you any platform is unsafe (which is technically true but realistically of course not so much), and they frequently like to pretend things like tracking cookies are the same as a malicious virus or trojan (even in these days when people willingly join facebook and surf around everywhere still logged into it). The other day I removed AVG from a Windows install because it was setting off alarms every time some poorly programmed application used a lot of memory. Just keep it in perspective. ¦ Reisio (talk) 16:40, 22 April 2012 (UTC)

Can I delete Restore Points manually?

On my WinXP system, I seem to have accumulated approx 75 restore points going back to the first of this year. It's literally thousands of files, and my weekly full scan spends about 20% of its time in C:SystemVolumeInfo (where I think it's highly unlikely to find any viruses...)

Accessories > System Restore doesn't have a "remove old restore points" option. Can I do it myself? Clearly there's a naming convention, and a date modified; can I just delete all the January and February directories? Or is it more complicated than that?

Thanks! --DaHorsesMouth (talk) 23:06, 21 April 2012 (UTC)

Good writeup here. --LarryMac | Talk 23:47, 21 April 2012 (UTC)

Feedback:

• Lockergnome advises using Disk Cleanup > More Options, which gives you no control over how many restore points to delete -- it kills ALL of them except the last. Not so sure that's a good idea.
• One commenter on that page advised using CCleaner > Tools, which I have now also tried.

• Prior to doing so, I had 75 directories named RPxxx (where xxx ranged from 646 to 719), containing about 14000 files. Each directory's "date last modified" matched up with the restore point date.
• After deleting January and February RPs, I have 13000 files in the same 75 directories, and the date last modified for the January and February directories (which are still there) are all now TODAY.

Ergo, I'm not sure it actually worked.

I'm not ungrateful for LarryMac's very prompt response, but I'm still open to other suggestions, if there are any. --DaHorsesMouth (talk) 00:22, 22 April 2012 (UTC)

Those directories' modification date is today because they were modified today (by deleting files from them). The other directories haven't been modified since the day they were created. I'm not sure why deleting two months of restore points (out of four) only got rid of 1000 files (out of 14000), but I suspect it's because files that haven't changed between restore points are stored only once. I don't know why CCleaner didn't remove the directories, but I wouldn't worry about that.

If your computer is working and virus-free, I think you may as well delete all of the old restore points since you're unlikely to need them. If you don't want to do that, and your only complaint is that your virus scanner is spending a lot of time under c:\System Volume Information, you could just exclude that path from the scan.-- BenRG (talk) 03:47, 22 April 2012 (UTC)

April 22

Problem using Chrome

When I start up Chrome, it starts eleven sessions of chrome.exe, which I can track using Windows Task Manager. It didn't used to do that. I thought it might have something to do with recently installing arcadecandy, because when I killed some of the chrome sessions, I got a notice saying that arcadecandy had crashed, even though it wasn't currently running, so I uninstalled arcadecandy and restarted my PC, but I'm still getting all of those sessions. Any ideas? 69.62.243.48 (talk) 02:34, 22 April 2012 (UTC)

I assume by "sessions" you mean "processes". You can use Chrome's task manager to see what each process is for. -- BenRG (talk) 03:54, 22 April 2012 (UTC)

Well, that cleared three of them, probably temporarily, but there are still eight processes open. But thanks. 69.62.243.48 (talk) 04:08, 22 April 2012 (UTC)

Chrome uses processes to contain malfunctions (this is why a single tab can crash, but not take others down with it). It might be optimisitically spawning processes for the first few tabs, or it might be using them to contain plugins, etc. Paul (Stansifer) 18:49, 22 April 2012 (UTC)

Changing the default video software and explaining my ghost in the machine

I have a Mac and I have Parallels Desktop. It is and has been closed. I downloaded some MP4s and the icons while they were downloading had the two red stripes indicating Parallels Desktop, which was weird in itself. When they finished downloading that went away and they changed to show an image from the video, I guess the opening shot. When I double clicked on one it automatically opened up Parallels and tried to run in Windows Movie Player. Ugg. I had to force quit Parallels and even weirder, after I did so, with it gone from the force quit applications list and not showing in the dock, the video image disappeared but the audio of the entire half hour MP4 ran, even though Parallels was by all appearances shut down, and WMV couldn't even be running without Windows! That I found really bizarre. Anyway, I can watch the video's fine by dragging them into (or choosing "open with") Quicktime Player or VLC, but I have no idea how to set each video to default to opening up in them. I will forget and double click and having to go through this rigamarole again. It's not a computer-wide thing. Other videos I have default to opening in Quicktime for example. So, how do I reset these videos so they default to the player of my choice? Also can anyone explain the twilight zone of the audio playing as I described it?--108.54.17.230 (talk) 03:01, 22 April 2012 (UTC)

It sounds as if the file type association has been broken somehow, although I have no idea how. Right-click or control-click the file, select "Get Info" from the menu, and then select VLC from the pop-up-menu under "Open with" to fix this. --Stephan Schulz (talk) 08:10, 22 April 2012 (UTC)

On ASIMO and his ability to pour liquids from one container into another

At 4:55 in this video, the robot ASIMO is able to twist open the lid of one container, and pour its contents into a cup. The amount of liquid in the container is much less than the maximum capacity that the cup can hold, and somehow ASIMO knows this and tilts the container to nearly vertical in order to get all of it into the cup.

Now, my question is this. Can ASIMO be programmed to do this with any size container and any size cup (I mean size in the sense of amount of liquid that can be stored, i.e. volume)? For example, let's say one container has 5 pints of water, and there are two cups, one that can hold 2 pints, and one that can hold 3. Assuming the only information that's "fed" into ASIMO is which is the container and which are the cups, could ASIMO be able to: view the cups, and determine the size and amount of water each can store, and then lift the container and a cup, and then when pouring from the container in to a cup, use scales in its arms to determine when the change in weight between the container and the cup in order to match, say, the density of water? I guess the pseudocode would be:

Container a;
Cup b;
Cup c;
a.liftL(); \\lift object with left hand
b.liftR(); \\lift object with right hand
m = a.weight();
Pour(a, b, m == 3); \\Pour the contents of first input into second input until condition third input is met
PlaceR();
c.liftR();
Pour(a, c, m == 0);
Return;

Would this be viable & generalized?--99.179.20.157 (talk) 12:39, 22 April 2012 (UTC)

I see a couple problems with that approach:

1) Dynamics. That is, the weight in the cup will appear to be heavier while liquid is landing in it. You'd need to let it settle down to get an accurate weight.

2) Condition 3. Since there is not a set cup weight empty to cup weight full ratio (a plastic cup is much lighter than an earthenware mug), what would this condition be ?

Most likely, it just pours for some set period of time, and they choose an appropriate cup so that this works out well, for the demo. StuRat (talk) 13:37, 22 April 2012 (UTC)

The goal of Asimo's intelligence software is to avoid "scripted" behaviors, such as the pseudocode listed above. (Scripted joint-control is old-fashioned robotics theory from the 1950s! Since at least the late 1960s, robotics research has centered on abstracting goals and tasks from their implementation. See SHRDLU for a start). Asimo's mechanical motions are programmed via an inverse kinematics solver in generalized coordinates, very similar to this open-source implementation of whole-body robotic coordination. Asimo's high-level task logic generates sub-goals, and these translate into objective functions for generalized "potential energies" - so the result is, in a high-dimensional space, Asimo's joints feel the force of "artificial gravity" tugging his hands towards what his AI goal is seeking to do. A feedback control system makes sure that he remains stable while satisfying a best-fit to the goal function, guaranteeing that he remains balanced while all of his many joint motors adjust for the correct position. This has an added benefit, for example, when pouring liquid. As the weight of the cup decreases, he is dynamically adjusting his motor controls to remain balanced and in the correct position, without needing an explicit script for the variations in the weight he's holding. If the simple script were used, Asimo's pouring script would fail if, for example, there was an invalid amount of water in the cup - which is undesirable. Nimur (talk) 15:53, 22 April 2012 (UTC)

For the very interested: according to the paper I linked above, one Asimo (or at least, the Asimo simulator) has actually loaded and executed the software. I believe the IK solver and the goals logic programs are all open-source, but Asimo is very expensive and proprietary. However, it is possible, with appropriate modification, to port the IK solver to your robot. If I recall, this is actually fairly trivial if you already know the mechanical properties of your robot; you essentially type your Jacobian matrix into the provided XML template, and ...presto - your PUMA thinks it's Asimo. As always, be careful with powerful software-controlled motors; I once had to wrestle a PUMA when a labmate punched in a wrong minus-sign; the robot nearly destroyed itself and its lab bench before he could reach the safety switch. Nimur (talk) 16:03, 22 April 2012 (UTC)

Additional batteries for laptop: Battery instead of DVD drive and USB battery

How do you call a battery that replaces a DVD drive? Can any new laptop be fitted with it? Can we connect a USB battery on any laptop? XPPaul (talk) 15:42, 22 April 2012 (UTC)

Those are quite broad questions; the simple useless answers are, of course: 1) A good idea 2) yes technically depending on your expertise 3) see 2 ¦ Reisio (talk) 16:45, 22 April 2012 (UTC)

To be pedantic, presuming you mean the battery is not just stuck any old place then the answer to 2 is incorrect. (If you are just going to stick it anywhere then number 1 is highly questionable.) A laptop without a DVD or same sized empty or filled with something that can be removed to be replaced space can't be fitted with such a battery. Nil Einne (talk) 17:08, 22 April 2012 (UTC)

Practically speaking, you need a laptop which has been build around a modular bay concept. It's e.g. theoretically possible to replace the DVD drive in a current MacBook Pro with an additional battery, but it is not practically feasible even for expert users. --Stephan Schulz (talk) 17:20, 22 April 2012 (UTC)

Although would it not be simpler to just buy a back-up regular battery?--Jac16888 ^Talk 21:19, 22 April 2012 (UTC)

On the Lenovo ThinkPad T410s that I'm currently typing this, I've slotted the second battery into the DVD drive bay. This battery is shaped in the same form factor as a laptop DVD drive. The DVD drive is safely in my laptop bag for use as and when needed. I believe this to be a common modular design for Lenovo laptops (those that have optical drive bays at any rate), and I'd be surprised if other manufacturers aren't doing the same. You don't even need a screwdriver, the drive/battery slides out with a simple pull-the-lever-that-releases-the-latching-mechanism-then-pull-out-the-drive/battery technique. Google Image Search will reveal all. I don't know if the battery has a special name other than "spare battery that fits into the DVD drive bay". A USB battery will be impossible as the USB port is not designed to receive current, nor is the circuitry of the motherboard designed to take advantage of a power source coming from a USB port.Zunaid 00:00, 23 April 2012 (UTC)

Earphone buzzing

Yesterday I broke the connectors inside my earphones and soldered them back together. But now there is a constant buzzing sound behind whatever I'm listening to on my computer. The computer speakers work fine, and other headphones work on it too, so I know it's not the computer's fault. The constant buzzing is getting annoying and making it hard to hear the music/talking. Does anybody have any ideas of the causes and perhaps some solutions too? Thanks, Rcsprinter (shout) 11:22, 22 April 2012 (UTC)

Usually a Mains hum due to Ground loop. It happened to me when my sloppy soldering burned through a wire's insulation. I had to separate the wire from the housing with a strip of paper. Jim.henderson (talk) 14:07, 22 April 2012 (UTC)

Unless they are really nice earphones, you can buy some new ones quite cheaply that won't buzz in the background. Astronaut (talk) 16:25, 23 April 2012 (UTC)

What is the difference between Java and Javascript?

Max Viwe | Wanna chat with me? 21:11, 22 April 2012 (UTC)

The languages are mostly unrelated, they just happen to share a similar name by coincidence. Javascript is an interpreted language used primarily for interactive web pages, whereas Java is usually compiled and run offline, although Java applets can be embedded on websites. →Στc. 21:17, 22 April 2012 (UTC)

Well, it appears that JavaScript was originally called LiveScript, and then renamed to JavaScript because it was more influenced by Java, so there is a connection in the names. →Στc. 21:23, 22 April 2012 (UTC)

(ec) They are two very different languages. See Java and Javascript. Java is a statically typed object-oriented language typically compiled to bytecode and executed on the Java Virtual Machine. It's used for all kinds of programming. Javascript is weakly typed, prototype-based (not class-based) language typically embedded in web pages and executed by an interpreter that is part of a web browser. It is most often used to implement interactive web pages. --Stephan Schulz (talk) 21:24, 22 April 2012 (UTC)

Java and Javascript are both related, quite distantly mind - they're both object oriented programming languages, but the primary difference between both is that Javascript simply has a smaller, easier command set to work with - it basically makes the language easier to understand. Java can basically work on its own, as an Applet, essentially a fully contained program, whereas Javascript needs to be put inside something else, like an HTML page in order for it to work.

Javascript is fed through a browser and then whatever is fed in, the browser produces the results of. The other thing is that Java needs to be compiled into machine language to produce an applet, but Javascript can be simply written as text, and added to an HTML page without any need to compile it. If I've missed anything, I'm sure someone will pick me up on it! Hope this helps. MarkBurberry32|talk 21:25, 22 April 2012 (UTC)

(It's possible to write standalone JS programs (and some people do!), but it's true that this wasn't JS's original purpose.) There's a good explanation on Metafilter. Essentially, other than superficially similar appearance, and the fact that both of them are some flavor of of OO, JavaScript might as well have been designed to be as different from Java as possible. I consider that a to be a good thing about JavaScript Paul (Stansifer) 21:50, 22 April 2012 (UTC)

hard disk capacity and speed

Hard disk capacity has been doubling about every 19.3 months, on the average, see File:Hard drive capacity over time.svg. I can't find any similar data for hard disk transfer speed, but it seems to me that the transfer speed has not kept pace with the increased capacity. Does anyone have any data on that? Bubba73 ^{You talkin' to me?} 22:23, 22 April 2012 (UTC)

There are lots of links in the references section of Disk-drive performance characteristics. Some of those might give you what you want. RudolfRed (talk) 23:54, 22 April 2012 (UTC)

That article says "These performance characteristics can be grouped into two categories: access time and data transfer time (or rate)." which is what I suspected. If I could find the typical transfer rate of a home computer MFM drive around the mid 1980s, I could answer my question. I found it for a commercial drive, but I don't know what it is for a home computer. Bubba73 ^{You talkin' to me?} 03:15, 23 April 2012 (UTC)

April 23

Laptop problems

I have a laptop running on six years old that appears to be slowly failing. What triggered this post was a problem that I've had in the past, but after a reboot I've been fine. Before I begin, I must admit that I do keep my computer on 24/7 and reboot it when it gets to a point of uptime-induced instability, but this is now happening even after a reboot.

I went to watch an MKV H264 480p file, but when I do, CPU usage goes through the roof (80%+) and the video desyncs from the audio. After a few days of uptime, but sometimes soon after a reboot, the audio will fail. Programs that rely on it working fail (Winamp reports "Bad DirectSound driver", Media Player Classic gives an AudioSwitcher:Out pin failure [I think that's what it says]). Similarly, CPU usage recently tends to go high for programs that aren't supposed to be using that much CPU, and sometimes to the point of crackling audio or lagging mice (I physically move the mouse, it doesn't move on the screen for 500ms-1000ms), which tends to be at 90%+. It gets to the point where I keep Javascript disabled for smooth browsing on sites that use it.

Even at idle, CPU usage is up around 40% and Task Manager lists items that should not be using that much CPU (e.g. Taskman itself using ~30%) and windows are lagging when I switch between them (e.g. between Firefox at this editing box and Taskman, elements from Taskman are left behind as it "unloads from view" [yeah, not the right term]). Printscreening and using scrollbars in Paint (mspaint) does not scroll smoothly anymore, but redraws lines so slowly you can see it as it moves to the new window position.

As I speak I can't play songs in Winamp without it causing 90%+ CPU usage, nor emulate (yes, I own them) at 60 fps; I get <10 fps in the emulators I try. It's so bad, I don't even want to try a resource-taxing game like The Sims or Portal. It's taking many times longer for programs to load than it usually does.

Specs:

- P4 2 GHz dual core (the dual core, in my first few years experience with this laptop, limits the high CPU usage to one core, but the 90%+ recent usage seems to not)
- 1 GB RAM
- 85 GB internal HD, two external worth 2.72 TB and 931 GB (yes, deceptive metric system advertising)
- GeForce Go 7300
- Sigmatel integrated audio

What I would like to know is if anyone can discern what is causing my problems. I understand it is incredibly difficult to do so using third-party information (e.g. you can't try it yourself, I'm telling you). Which component of my PC is likely to be causing these problems?

As an aside, while typing this post, I noticed my keyboard's repeat rate appears to have gone down. I went to the Control Panel's keyboard config, but it's up as far as it can go. It was fine before the most recent reboot. The aforementioned problems are even causing my keyboard input to lag as I mentioned my mouse does. -- Tohler (talk) 00:03, 23 April 2012 (UTC)

After a failed shutdown, I thought "I wonder what process is holding the shutdown" and became frustrated enough that I began killing them. For a little while (15 minutes), everything worked fine again (yes, even with a failed shutdown) except for Firefox 3 couldn't load pages (my primary is 1.5; yes I'm extremely outdated). A little more insight into the situation... -- Tohler (talk) 00:40, 23 April 2012 (UTC)

Yes very difficult to discern, but it seems to me that Windows (I presume XP?) needs a complete reinstall. What I mean is: backup, format, install from scratch. After six years of usage there could be any amount of spyware/clutter/etc. floating around and this is even with a decent antivirus installed. There may be other ways to fix it but these could be long-winded. If the laptop still displays strange behaviour after a fresh install, then you can look at trouble-shooting hardware issues. Sandman30s (talk) 12:54, 23 April 2012 (UTC)

^ I agree, most Windows installs just get more and more crufted over time, eventually forcing a reinstall. You could switch to Linux, too. :) If you decide it's a hardware issue, after six years you should probably just replace it — you can probably get a new laptop with more than twice the processing power and probably quadruple the RAM for around $350 (at least in the USA), which is probably less than half what you paid for this machine six years ago — one perk of living in the future. ¦ Reisio (talk) 15:39, 23 April 2012 (UTC)

If you want to continue with your current laptop, the complete Windows reinstall is the way to go. Small improvements that would work out cheaper than a new laptop are more memory and a bigger hard drive, but you might struggle to find compatible components at the best prices and hardware limitations might restrict how far you can upgrade. However, that doesn't help improve the CPU speed and screen resolution, which is fixed for almost all laptops, and I wouldn't mind guessing the battery life is almost zero if you dare unplug it from the mains power. Astronaut (talk) 16:22, 23 April 2012 (UTC)

Do you have reason to believe H.264 480P will work on your computer? If your computer is really dual core pentium-D it may, although I wouldn't guarantee it. It also depend on the profile of the encoded video of course. If its single core with hyperthreading (if it's called a Pentium 4 it's probably the later since NetBurst were always officially called Pentium-D) there's a chance it won't. You can try CoreAVC and see if it improves matters or you may just have to upgrade. In any case you should expect high CPU usage. With a Very weak CPU and GPU, the inability to run even old games like Portal at 60fps is hardly surprising. Nil Einne (talk)

I've made h.264 work up to 1024p on my 2004 single-core p4. Required the following setup if I can remember correctly: Nvidia pure video (not needed any more), Sonic HD Decoder, latest CCCP drivers and the only player that could play it reliably was Media Player Classic. I even managed to play raw bluray files via this setup, and bluray discs via an older version of PowerDVD (I think 7.3) with a HD playback kit. I think at the time I had a 6000-series nvidia card in it. Of course currently there are tons of software and media players that can play MKV but you'd be surprised at the power of computers of ten years ago and how much can be squeezed out of them. Sandman30s (talk) 19:37, 23 April 2012 (UTC)

- Sandman & Resio: Yes, I am running XP. I have actually thought of multibooting with Ubuntu the next time I get a new computer. What distro do you use? Similarly, do you multiboot, and if so, what steps/programs do you recommend? I have no experience multibooting in the past. I plan on multibooting with XP, Vista/7, and Ubuntu; I'd also enjoy running 98 or 95 non-VM for the nostalgic factor but I'm wondering if the differing filesystems will cause a problem.

- Nil Einne: Yes. In the past I have been able to run 480p with no trouble. Even 720p worked fine most of the time. When I mentioned I didn't want to run Portal or The Sims, what I meant was that I didn't want to run items with even higher requirements given that light usage as described caused all these problems.

- Astronaut: By resolution do you mean display resolution? I'm running 1680x1050 with an external monitor. You are semi-correct about the battery - it can't hold a charge for as long/as much of a charge as it used to.

- Six years ago I bought my laptop for my college career. Today I have no need for mobility with my computer. With today's technology, is there a large difference between a tower and a laptop? (I do have a tower, but it's even older - 2003) However, I would be interested in a $350 laptop for those instances where I may be required to travel for my job; do you recommend a specific brand/company that would give said specs/price?

- Do you guys recommend the buying of individual parts/self-assembly or the buying from a company like Dell (where my tower and laptop came from)? Do you recommend any other companies?

- One thing I would like to do is keep the data that is currently on my hard drive. If I get a new system with a new HD and the OS installed on that, would it be wise to hook my current-laptop HD up as a secondary HD, or copy the data over to the new one?

- One minor unrelated question that I don't want to start a whole new question for. For example, on the TV Tropes site, when describing a fantasy TV show with doppelgangers/fakes, I see phrases like "Real!Joe" and "Fake!Joe". It's quite obvious the form is (descriptor)+(name), but why is the exclamation mark used? Where did this "tradition" come about and why is it used in place of something like a dash ("Real-Joe")?

Thank you all for your help! -- Tohler (talk) 20:14, 23 April 2012 (UTC)

wrong fonts?

why my computer is not able to display some languages? like in this example (look at double squares):

search • suchen • rechercher • zoeken • ricerca • szukaj • buscar • поиск • 検索 • busca • sök • 搜尋 • tìm kiếm • пошук • cerca • søk • haku • hledání • keresés • 찾기 • cari • ara • جستجو • căutare • بحث • hľadať • søg • serĉu • претрага • paieška • poišči • cari • חיפוש • търсене • іздеу • bilatu • suk • bilnga • traži • खोजें

Thanks, John — Preceding unsigned comment added by 69.86.231.47 (talk) 01:32, 23 April 2012 (UTC)

I think that's more of an issue with your browser, rather than your computer in general. Are you using Internet Explorer? See the following page for more information: http://support.microsoft.com/kb/928847. I use Firefox and those characters display without any problems. This page should be in UTF-8, which supports those characters. If you set the font manually, it should display in your browser, like this:

search • suchen • rechercher • zoeken • ricerca • szukaj • buscar • поиск • 検索 • busca • sök • 搜尋 • tìm kiếm • пошук • cerca • søk • haku • hledání • keresés • 찾기 • cari • ara • جستجو • căutare • بحث • hľadať • søg • serĉu • претрага • paieška • poišči • cari • חיפוש • търсене • іздеу • bilatu • suk • bilnga • traži • खोजें

—Best Dog Ever (talk) 02:20, 23 April 2012 (UTC)

This image shows what it looks like in Firefox 3.0. It also shows how to get to Firefox 3.0's character encoding selecter. -- Tohler (talk) 04:58, 23 April 2012 (UTC)

Depending on which squares you're seeing, you may simply be missing required fonts. http://www.alanwood.net/unicode/fonts.html ¦ Reisio (talk) 15:41, 23 April 2012 (UTC)

Name for digital projection concept ?

If I project an image in such a way that it is foreshortened, this results in multiple pixels on the original mapping to the same pixel in the projection. This produces the following ugly image when I project a grid:

If, however, I don't project the background pixels, this avoids overwriting any foreground pixels, producing a much better result:

So, is there a term for this problem, and/or this solution ? StuRat (talk) 05:56, 23 April 2012 (UTC)

The problem is a kind of aliasing artifact. The solution in general is to use spatial anti-aliasing techniques. Looie496 (talk) 06:41, 23 April 2012 (UTC)

Thanks. Any name for this specific technique, or the related technique of projecting colors closer to the background color first ? StuRat (talk) 14:10, 23 April 2012 (UTC)

You just worked around the aliasing and moire, by intentionally not drawing the entire image at the same time. This worked for simple line art, but the technique does not work in general. I'm not aware of a name, other than line drawing with a paint order. Several algorithms specify a paint order, like any z-buffering technique or the painter's algorithm, but those are intended to solve clipping problems, not antialiasing. If you want to get this working in the general case, you do need to actually use spatial antialiasing. There are many names for specific implementations of antialiasing filters. Nimur (talk) 15:03, 23 April 2012 (UTC)

I'm more interested in high-speed rendering of wireframe animations than slow, shaded image rendering, so this method works best for me. StuRat (talk) 18:39, 23 April 2012 (UTC)

If your wireframe animations contain high spatial frequencies, they will also alias. You got lucky this time. If you are using hardware acceleration to render, (e.g., OpenGL running on almost any reasonable GPU), there is no speed-penalty for enabling antialiasing, using e.g. glHint(GL_LINE_SMOOTH_HINT, GL_NICEST). Your mileage will vary, depending on your graphics driver; of course there are better ways to antialias in special cases. (With due respect, StuRat, I'm really expecting you to come back and tell me you're using FORTRAN code to software-render pixel-values into a text-document, which you convert to GIF using a Windows program; in that case, you're fooling yourself if you think antialiasing has any performance impact on your workflow). Nimur (talk) 18:46, 23 April 2012 (UTC)

Almost. I'm using a FORTRAN program to create PPM panes, which are then stitched into an animated GIF using ImageMagick. Each pane takes about 7.5 milliseconds to render, at 400×400 resolution. That seems plenty quick, to me. I have a low-end CPU (Pentium 4, 2.8GHz, running Windows XP SP3), and hardware acceleration is not available. StuRat (talk) 18:56, 23 April 2012 (UTC)

Here's a wireframe animation I created which requires red-blue 3D glasses:

My 3D animated grid (2 corners appear to peel up). For best results, pick on it, then select full resolution, below.

I intend to add more frames to it, later. I've also created shaded animations, where I render the shading first, then add a grid on top:

Fountain animation.

Morphing 3D graph.

19:10, 23 April 2012 (UTC)

StuRat, these are very nice animated plots, but you're really going to a lot of effort because you're using the wrong tools for the job. For example, GNU Octave (which is totally free software, and runs on Windows), can generate 3D plots using the mesh() functions. In fact, you can plot many different types of wireframe and smooth surfaces; you can perform animations, output as discrete image frames, or compress as a movie file, all using free and open-source software that even runs on Windows. A task that will take you hours of FORTRAN programming can be accomplished in mere seconds if you select a reasonable toolkit. If you're just doing this for the joy of re-implementing the mathematics of elementary shaders and lighting and projection geometry, then your efforts are not in vain (but, you should spend the effort to learn how to do it right - antialias!). If you're simply using your program as a means to generate nice animations, you should reconsider your toolkit. Your Pentium 4 is a fine processor. It can easily handle these sorts of calculations. Almost certainly, your system has some capability to hardware-accelerate OpenGL, even if you lack a discrete graphics daughtercard. Almost every Pentium-class system has a simple GPU integrated into the system. If your Pentium 4 is outputting to a monitor in any way at all, then it's a sure bet that your motherboard has one of these Intel chipsets, which includes one of these graphics units, which support at least OpenGL 1.4 - which contains an advanced feature set far beyond you need for simple surface rendering, wireframe animations, and other graphics and animation. Sure, it'll cough and stutter when you try to run the latest and greatest games, but accelerating your 400x400 pixel wireframe renders will be no problem. Nimur (talk) 23:16, 23 April 2012 (UTC)

This is a hobby of mine. Your comment comes across a bit like telling someone who likes to garden that they can just get flowers already grown, so they should stop wasting their time. It's not just about the results, it's about doing it for myself. I also disagree with the idea that there is only one right way to do things. If that was the case, we wouldn't have wire frame, surfaced, and solid models. The reality is that different methods are better for different purposes. StuRat (talk) 03:17, 24 April 2012 (UTC)

"X" Power button light of Xaser VI

Hello there, yesterday I cleaned up my pc and disconnected two optional fan inside the case that has been damaged for a long time. After that I turned on pc by pressing power button "X" and noticed that "X" power button light does not blink though my system is running smoothly. The HDD light blinks. I reopened the case and made sure the peripherals are connected properly. But the button still does not blink. How can I address the problem? Am I missing something? thanks--180.234.236.182 (talk) 09:56, 23 April 2012 (UTC)

Power buttons don't normally blink, they are steady on when the device is on. Is this how it behaves now ? If so, this is what it should be doing, and the damaged fans were likely causing voltage drops making it blink. If the light isn't on at all, then something else is wrong. Perhaps you accidentally disconnected the power cord to it. Or, perhaps it just burned out, coincidentally, at this time. StuRat (talk) 14:08, 23 April 2012 (UTC)

• You are right. The light is not On when I press on it and even it stays in same situation when pc is turned on . I checked the disconnected power cord but couldn't locate it. Does it look like two pin cord? I read the manual of thermaltake Xaser VI where case LED connections are mentioned: Power Led, Power SW, H.D.D Led and Reset SW. I found all of them except Power led cord (two pin). Is the power Led cable responsible for this? I overlooked it but couldn't find that cable. Is it really burned out? Can you please tell me which cable is responsible for power button light. Thanks--180.234.238.230 (talk) 17:33, 23 April 2012 (UTC)

• I'd expect it to be a two-pin power cable, yes, but I'm not certain. Is it possible you removed it, thinking it went with one of the fans ? If not, it should still be inside the computer. If you can't find it near the on/off light, look for where the other end should plug into the power supply unit (which is where the cord from the wall outlet plugs go into the computer). StuRat (talk) 18:31, 23 April 2012 (UTC)

• One more thing is that I disconnected my hard drive and reconnected it. Does the light of power button have to do anything with connecting and disconnecting with harddrive?--180.234.238.230 (talk) 19:17, 23 April 2012 (UTC)

• OK, I bet what happened is that your PC lacks an ON/OFF light, and the hard drive has a light that is on whenever it is powered (which was whenever the PC was on). By disconnecting the hard drive, you also lost that light, which was your only visual indication that the PC is on. When you reconnected it, you probably didn't get the plug all the way in, so it doesn't have power to the light. Try pulling the plug all the way out, and completely reseating it. Also check that you didn't bend any of the pins. If so, try to bend them back. StuRat (talk) 19:23, 23 April 2012 (UTC)

• I have just rechecked inside the case and finally, yes, I found that four-pin power cable. Actually that cable was associated with damaged case fan and was connected to PSU power cord. While disconnecting the fan I mistakenly disconnected it from PSU power cord. Now the light is back again. Thank StuRat for helping me out.--180.234.198.76 (talk) 20:20, 23 April 2012 (UTC)

• You're welcome. StuRat (talk) 20:26, 23 April 2012 (UTC)

Resolved

Wouldn't it be nice if...

a blogging programme checked some bit of metadata on an image to see how big it is, before making me wait several minutes while it tries to upload it, only to realise the image is too large?

Wouldn't that seem like an easy/obvious feature to add to, say, Blogger?

Adambrowne666 (talk) 10:02, 23 April 2012 (UTC)

The HTML support for file upload just lets the user choose a file, and sends it across. Allowing scripts to interact with the process would threaten to create security holes. Paul (Stansifer) 13:53, 23 April 2012 (UTC)

Of course, you could always check yourself how big the file is - after all it is being uploaded from the computer you are currently using isn't it? Astronaut (talk) 16:06, 23 April 2012 (UTC)

Both good points, but you neglect to factor in the datum that I'm very lazy, too shiftless to care even about security issues.Adambrowne666 (talk) 23:51, 23 April 2012 (UTC)

LaTeX figure numbers

I am trying to number figures in a certain way and am having difficulties. What I want to achieve is the following.

1. Number as (chapter #).(section #) if the figure is not within a subsection (meaning that the subsection counter is set to zero), and (chapter #).(section #).(subsection #) otherwise.
2. Follow this with -# if the subsection has more than one figure, and nothing otherwise.

I have achieved the first bit with

\newcommand{\figureplacenumber}{ \ifnumequal{\value{subsection}}{0}{\arabic{chapter}.\arabic{section}}{\arabic{chapter}.\arabic{section}.\arabic{subsection}} }

\renewcommand*{\thefigure}{\figureplacenumber-\arabic{figure}}

However, this leaves a space between the (sub)section number and the hyphen, and this space does not disappear with

\newcommand{\figureplacenumber}{ \ifnumequal{\value{subsection}}{0}{\arabic{chapter}.\arabic{section}\xspace}{\arabic{chapter}.\arabic{section}.\arabic{subsection}\xspace} }

or

\renewcommand*{\thefigure}{\figureplacenumber{}-\arabic{figure}}

and I haven't a clue how to achieve the second part. What should I do? Thanks.--Leon (talk) 10:43, 23 April 2012 (UTC)

Private email communication

How can I communicate privately through email? I don't want commercial providers snooping through my emails to offer me stuff. XPPaul (talk) 12:37, 23 April 2012 (UTC)

I note that Gmail is now reading the contents of my emails and advertising based on it, which rather sucks. I assume this is what you mean. Some type of encoding could work, but the recipient would need to be able to decode it. StuRat (talk) 14:04, 23 April 2012 (UTC)

Encryption. --Mr.98 (talk) 14:05, 23 April 2012 (UTC)

You use an email provider that snoops through your mail in oder to advertise stuff to you????? That has never happened to me in 20 years of using email, not even webmail providers like Hotmail or Yahoo. I suggest you change your provider immediately. I expect it would be easy to find a provider who won't do this. On the other hand, many email providers have a clause in their terms to allow them to release your emails to the relevant authorities under a legal request (for prevention of terrorism and so on) and have a means to store your mail for that reason. Astronaut (talk) 16:04, 23 April 2012 (UTC)

If you securely encrypt your mail (really securely), your email recipients will need to securely decrypt it. This requires technical knowledge (not much, but just enough that many people will not bother to do it). To the uninitiated, a secure email using, e.g., S/MIME, appears to be an almost-blank ordinary email with a strange binary attachment.

The sad reality is, if you wish to communicate securely, you must seriously limit who you communicate with. Nimur (talk) 17:29, 23 April 2012 (UTC)

As Mr.98 suggested, encrypting your emails is the only way to stop email snooping (through something like PGP). It's not particularly difficult to do, but as Nimur suggested, it severely limits who you can talk to. The other comment I wanted to make was that pretty much all email providers will read your mail contents, not just GMail. As this is how they filter spam. - Akamad (talk) 22:47, 23 April 2012 (UTC)

Webcam formats?

I wonder in what format typical webcams transmit video to the computer. Is it some standard format that the OS knows, or is it some camera-specific raw format that the driver converts in real-time to a standard format? In the latter case, what format does the driver present to the OS? AxelBoldt (talk) 18:18, 23 April 2012 (UTC)

Frequently JPEG, AIUI. ¦ Reisio (talk) 18:24, 23 April 2012 (UTC)

The standard for USB video is called USB video device class, and as Reisio points out, often involves JPEG-compressed frames. Your webcam can do anything it likes if it uses a non-standard device driver.

For example, Video4Linux 2 defines several types of uncompressed and compressed formats. It is the responsibility of the device-driver and kernel-driver to negotiate the format so that meaningful video data streams from source to destination.

The source-code for Video 4 Linux, including the USB driver, is distributed as part of the kernel, available at http://kernel.org and documented in linux-(release)/Documentation/video4linux/uvcvideo.txt - you can download it for free and read all the technical information you need, with no details left out. Nimur (talk) 19:03, 23 April 2012 (UTC)

Some Computing questions

1)Using VoIP, the person who receives the call, gets a random and weird number on his caller ID.Such way, if a person threatens a person over phone via the VoIP, Can the law enforcement trace the location of the phone using the weird number?

2)While the torrent sharing website provide illegal software and other stuffs, Why the government is not taking any action against them?

3)Is there any Xbox 360 emulator available for Windows?Max Viwe | Wanna chat with me? 19:50, 23 April 2012 (UTC)

(1) I don't know. Perhaps your VoiP provider can answer this for you. (2) Copyright is often enforced in civil court via lawsuit by private parties. For example, see the article on the Pirate Bay trial and also the RIAA. (3) This page claims to have an XBox 360 emulator: [3]. RudolfRed (talk) 20:33, 23 April 2012 (UTC)

The Xbox 360 emulator is probably a scam. The "newest updates" bullet points are copied from pcsx2 checkin comments ([4]). See also WP:Reference desk/Archives/Computing/2012 January 19#Xbox 360 emulator.

It has been difficult to take legal action against torrent sites because nothing that they host (torrent files, torrent descriptions, torrent tracking data) actually infringes on copyright. The copyrighted data is sent directly from peer to peer, and the web site is not a peer. -- BenRG (talk) 23:49, 23 April 2012 (UTC)

Firefox Addons that can make browsing quick by using alphabet

Hi there, A few days ago I installed an addon which make browser easier by using alphabet. User can press ctrl+spacebar or ctrl+shift to bring a small interface which can show the name of the website along with an alphabet (e.g. facebook f) that can directly lead user to that particular website in a new tab if user presses the alphabet associated with the website. For example: http://www.facebook.com = f, http://www.wikipedia.com = w, http://www.youtube.com= y. User can add any website by go to the option of that interface and add web address with certain alphabet that is convenient for user. Can anyone help me to find that addons. Thanks in advance--180.234.198.76 (talk) 20:36, 23 April 2012 (UTC)

You can do the same with Firefox's bookmarks. Open up the Bookmark Manager and to the New Bookmark prompt. Add the Name and Location of your choosing, then put the letter of the alphabet you want in the "Keyword" section. Hit Add to make your bookmark. Now you can use the alphabet as you wanted. -- Tohler (talk) 21:06, 23 April 2012 (UTC)

Vimperator? There are (as usual) one or two alternatives, too, IIRC. ¦ Reisio (talk) 22:18, 23 April 2012 (UTC)

• Apparently it's not that one I am looking for!--180.234.198.76 (talk) 22:38, 23 April 2012 (UTC)

You're right, it's one of the ones listed in Vimperator's external links section. ¦ Reisio (talk) 01:15, 24 April 2012 (UTC)

April 24

Javascript unlimited multiplier.

What's the best possible way to make a multiplication in javascript without getting exponential number or "Infinity". 190.158.212.204 (talk) 02:15, 24 April 2012 (UTC)

I don't know about Java specifically, but, in general, the only way to support an unlimited length number, whether integer or real, without going to exponents and/or hitting a precision limit, is to store it as a character string and do all the calculations manually. This is quite painful. StuRat (talk) 03:10, 24 April 2012 (UTC)