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July 22

restoring read-only files to read-write

Somehow, I don't know how, all my files in a few folders were made into read-only. Is there a way I can make them all read-write again? (I wonder if it happened due to some combination "shortcut" keys I accidentally typed (being a poor typist)?) The OS is Vista. --Halcatalyst (talk) 01:02, 22 July 2011 (UTC)

You should be able to change it in the folder/file properties. Right-click on a folder or file, then go to properties. Down the bottom is a tick-box option for read-only. - Akamad (talk) 01:27, 22 July 2011 (UTC)

That was easy! Thank you very much. --Halcatalyst (talk) 02:32, 22 July 2011 (UTC)

Radio on the ipad

Hi. Is it possible to listen to BBC Radio 4 on the ipad? Googling left me utterly confused. Thanks, Robinh (talk) 01:25, 22 July 2011 (UTC)

It is. Just open the web browser, go to the Radio 4 website (bbc.co.uk/radio4) and click on the play live. Hope this helps. Rcsprinter (talk) 12:00, 22 July 2011 (UTC)

hi. nope, does not work; when i try, it says I need to download flash, which does not work on the iPad. any other ideas? Robinh (talk) 04:15, 23 July 2011 (UTC)

See here http://faq.external.bbc.co.uk/questions/radio/online_radiohowto/?src=interstitial for non-flash Radio access to BBC Radio. ny156uk (talk) 06:53, 23 July 2011 (UTC)

or get the bbc iplayer app for Ipad (sorry that's probably a simpler solution - it's free too, at least here in the UK). ny156uk (talk) 06:55, 23 July 2011 (UTC)

Thanks for this. Unfortunately I seem to be hitting brick walls (I'm based in NZ, which seems to make a difference). There doesn't seem to be an ipad app that works for radio, and the BBC FAQ doesn't seem to help. Does any refdesker not in the UK have access to Radio 4 on an ipad? Cheers, Robinh (talk) 08:09, 23 July 2011 (UTC)

Are security requirements considered to be a Non-functional requirement

It is certainly on the list in the article, but many elements seem to me to be functional requirements. For example audit, non-repudiation, single sign on, etc. -- Q Chris (talk) 12:40, 22 July 2011 (UTC)

The difference is purely semantic. Various authors of systems-engineering textbooks will use different terminology to describe system design. Nimur (talk) 16:27, 22 July 2011 (UTC)

Security requirements are usually categorized as non-functional requirements. However, depending on the requirement, sometimes specific features, behaviors, and/or design choices are mandated. You can make a good argument that requirements like that are not non-functional. The bottom-line is: categorizing requirements is just a practice for organizing and managing them; it does not affect the substantive criteria that define what an acceptable solution is. The important thing is you have a complete, correct, and well-expressed set of requirements. There is some value in organizing requirements into categories, but beyond a certain point, finding the single "correct" category to put a requirement in may become an unproductive exercise, especially if it involves hair-splitting. --98.114.98.196 (talk) 14:22, 23 July 2011 (UTC)

Facebook down?

I keep getting "Account temporarily unavailable Your account is currently unavailable due to a site issue. We expect this to be resolved shortly. Please try again in a few minutes." Anyone else having problems? DuncanHill (talk) 13:29, 22 July 2011 (UTC)

Nope. But it has been a few minutes since you posted this. --Mr.98 (talk) 14:05, 22 July 2011 (UTC)

I find the site http://www.downforeveryoneorjustme.com/ to be quite useful at times like that. ny156uk (talk) 06:52, 23 July 2011 (UTC)

I don't think that would work in this case. DuncanHill isn't claiming that Facebook is offline entirely, just that they're having some sort of malfunction. DownForEveryoneOrJustMe.Com would connect to facebook dot com, retrieve their page that says "Account temporarily unavailable..." and say "Yup! This web page is still online! It's still serving content!". It's not smart enough to know that the content is just a page explaining that facebook isn't working. APL (talk) 10:16, 23 July 2011 (UTC)

Thanks, sorry I didn't get back sooner. Well, it resolved itself after a few minutes. What was puzzling me was that although I've occasionally have Facebook go down entirely, I've never had the "Account temporarily unavailable" message before. DuncanHill (talk) 16:06, 24 July 2011 (UTC)

what's the best computing language to learn?

Hi folks :) is C++ the best all-purpose computer language to learn if one is interested in a career in comp/sci or programming, or has Java or C-sharp taken over? It's been emotional (talk) 18:22, 22 July 2011 (UTC)

You should learn several programming languages if you intend to become a professional software engineer. After you have learned three or four different types of languages, you should take a break, far from any computers (I recommend a camping trip without any electricity or network connection). And, you should sit alone in the woods, and say, "Am I a Systems Programmer? C : Java;" Nimur (talk) 18:32, 22 July 2011 (UTC)

C/C++ is the most all-purpose language in that if you know the basics of C/C++, you can quickly pick up all the other popular languages. As an example: Technically, I learned assembly first, but my first normal language was C, then C++. In the military, I needed to know COBOL. I picked it up while flipping through a COBOL manual in the truck on the way to the programming office. Then, in college, I needed to know Java. I flipped through a Java textbook and picked it up in a couple hours. A harder one was ADA. I needed it for an Air Force contract. It took me a weekend to pick it up. You don't become an expert programmer in a couple hours, but you "get" the syntax because it is very similar to C/C++. Then, you can quickly look at how it is different from C/C++ and go from there. I see it as starting at the trunk of the programming tree and going out on the branches. If you first learn the tip of a branch, it takes a lot more effort to figure out how to work at the tip of another branch. -- kainaw™ 18:48, 22 July 2011 (UTC)

Thanks, very helpful advice. Nimur, is it a compromise if I just find some place like the one on your userpage? I'm not good at surviving without electricity, although I could probably make do without a network (read: Wikipedia) for a while, just to get some work done :) It's been emotional (talk) 18:59, 22 July 2011 (UTC)

I always suggest that people start by learning a simple, clean, powerful language like Racket or Python. Industry-oriented languages have a lot of cruft that can get in the way of the really important stuff. If the only language you know is some big, heavy thing like Java or C++, you'll tend to focus too much on trivial decisions instead of on getting a good overall design. Picking up new languages is easy, but learning how to think about computation is hard and very important, so learn with as clean and simple a language as possible, not one that was designed to trade programmer effort for faster execution time. Paul (Stansifer) 23:46, 22 July 2011 (UTC)

I think that's good sound advice. Also you should always try scripting the use of other tools first when solving a problem, it's normally far faster at getting an adequate solution and shows up any real problems much quicker than rolling your own. Dmcq (talk) 15:38, 23 July 2011 (UTC)

Norton Anti-Virus

Resolved

I have realised (somewhat to my shock) that over half of my laptop's internal hard drive is given over to Norton's "Virus Defs" folder.

I'm keen to free up that space on the computer. So my question is this: if I move that folder to an external hard drive, how can I make Norton "map" to the new location and find its Virus Defs there? And, of course, force it to update its Virus Defs at the new location, also, whenever it updates? AndyJones (talk) 21:33, 22 July 2011 (UTC)

Either your laptop has a very small hard drive, or you should replace Norton. I'd probably replace Norton regardless, it's awful. ¦ Reisio (talk) 02:10, 23 July 2011 (UTC)

Well I'm personally using Norton Internet Security 2011 and I don't have any problems with it. I don't know if perhaps your experiences are based on versions from about 5+ years ago (which truely were bloated/terrible), but the last few releases haven't caused me any issues or noticeable slowdown, it just works. To the original poster, the definition files should be around 200Mb in total, at least that's what I get based on definitions released a few hours ago. My version is only keeps the latest definitions though so depending on which version of Norton you have it may be storing the previous 2-3 different defintions and thus 3 times that disk space. If you have considerably more space being used than that being used though then it might be worth uninstalling and reinstalling it to see if that fixes the problem. As far as I know though it isn't possible to move the definitions to another drive, probably because they're treated as critical files and therefore must/should be available at all times and as such the C: is the only place for them, but another person may know otherwise!  ZX81  ^talk 02:26, 23 July 2011 (UTC)

Seems to only get worse as time goes by IME. 2011 still needs a "removal tool" to uninstall it after you "uninstall" it, right? :p ¦ Reisio (talk) 07:27, 23 July 2011 (UTC)

To put my question into context, the VirusDefs "properties" dialog tells me it has a "size on disk" of 34.8GB, and contains 15,426 files in 781 folders. The answers above suggest it shouldn't look like that, at all. Is there any merit in just removing the folder (onto a backup disk rather than just deleting), then sending Norton off to do a live update (which would presumably restore the current set only)? AndyJones (talk) 11:43, 23 July 2011 (UTC)

Thank you to those who replied. Problem resolved by using the Norton removal tool. AndyJones (talk) 13:10, 23 July 2011 (UTC)

July 23

Sata power connector

I'm building a computer, and most of it is functional, but when it boots, neither the HD or OD are recognized. The light on the optical drive doesn't turn on, I can't eject either, and the hard drive isn't spinning, so I'm assuming it's a problem with the power somehow. The cable I'm using is a Cooler Master cable that looks like this. I tried swapping in a hard drive I know works, but that didn't work. I also tried switching the SATA power cable for a 4-pin molex, and using an adapter to change that to SATA, but that didn't work either. However, when that same molex cable is connected to the fans, it works just fine. How would I find the source of the problem? KyuubiSeal (talk) 02:36, 23 July 2011 (UTC)

Does the optical drive light come on if you unplug the data cable while leaving the power plugged in? Nil Einne (talk) 08:41, 23 July 2011 (UTC)

I suspect that the fan is more tolerant of power that's outside of specs, like low voltage. Those other devices might even have safety features to prevent operation (which might cause damage) using a defective power supply. Try swapping in a new power supply. StuRat (talk) 14:12, 23 July 2011 (UTC)

I don't happen to have another power supply on hand. I do have a voltmeter though. Would it be safe to test the voltage and current on either cable while it's running? KyuubiSeal (talk) 14:35, 23 July 2011 (UTC)

Sure, that's easy enough for the Molex connector, but trickier for the SATA. Black->yellow should be 12V and black->red should be 5V; note that systems frequently draw maximum power for a few seconds as they boot, so watching the voltages as the system boots (rather than when it's quietly cruising along) can be instructive. That said, in my experience, when the drive-connector rails in a PC PSU are overtaxed the symptom is usually that a given drive starts, spins up, and then is depowered (sometimes a cycle of powerup/down develops). For neither device to even start to spin up would suggest the power isn't getting through at all, or at a very low voltage, suggesting either a bad connector somewhere or a defective PSU altogether. -- Finlay McWalter ☻ Talk 14:58, 23 July 2011 (UTC)

You were right, very little power was coming through. Also, a few minutes after we tested it, there was a huge spark, the fan stopped, and no power came from any port. Could have damaged something if we hadn't disconnected it to test it. Thank you so much! KyuubiSeal (talk) 02:11, 24 July 2011 (UTC)

Facebook - Exporting list of page fans ('likes')

Hi, does anybody know a straightforward way to export a list of people that 'like' a facebook page that you are an admin on? I've had a look through facebook, and range range of blogs and articles about it, and I cant seem to find an easy way to do this that appears entirely white-hat - We don't want to do anything that facebook or our fans might react poorly to.

In my case, I would need to be able to export the public names of several thousand profiles that 'like' the page. This isn't for any devious purpose, the place where I work operates a number of different internal and external digital social platforms, and we want to avoid bombarding people that may have accounts across several of those platforms with the same information. Ideally, if it is possible, I would like to be able to export as a CSV (or anything else easily compatible with Excel).

I can't find anything on facebook that forbids doing this, nor can I find anything that says it is ok to do this.

Facebook does appear to have a tool that allows you to do something similar for facebook groups, but hasn't rolled out a tool for 'pages'.

I keen to hear about any thoughts, experiences or tips you might have.

Thanks Computing helpdesk people. 86.182.254.23 (talk) 11:37, 23 July 2011 (UTC)

Enumerating "likes" certainly seems to be supported by the Facebook graph API (docs). -- Finlay McWalter ☻ Talk 11:46, 23 July 2011 (UTC)

Hi, thanks, I did have a look at that page, but I am afraid to say it mostly went over my head, and I wasn't sure if I could use it to do what I want. Given that you suggest I may be able to use that to pull out the details I'm after, I may invest some time in working out how to use the API properly. Thanks Finlay McWalter 86.182.254.23 (talk) 12:27, 23 July 2011 (UTC)

These APIs are intended for an audience of programmers, most of whom manipulate them through a wrapper adapter specific to whatever programming language they're using. The APIs show that, at least in theory, the information you want is accessible to programs (although I've not read the terms-of-service carefully; API users tend to have to be careful in that regard, lest they be treated as being not entirely white-hat). But if you're not a programmer, and don't have the help of one to hand, the mere evidence that an API exists which could allow a program to do what you want obviously isn't the same as actually having such a program. You may need to recruit a programmer temporarily, if no-one else can find a pre-existing program that uses the API in the fashion you want. -- Finlay McWalter ☻ Talk 14:29, 23 July 2011 (UTC)

Hi Finlay McWalter, thanks for the additional reply. I can confirm that I am in no way what-so-ever a programmer, although, I do pick things up reasonably quickly. If I can't master the programming quickly (which I assume will be the case), I shall ask the powers-that-be how much they want to invest to pull in the data. I really do appreciate your additional advice, it is very helpful. In the words of my peers: "Cheers" (poet, didn't know it etc.), 86.182.254.23 (talk) 17:00, 23 July 2011 (UTC)

Facebook has created a Graph Explorer to walk the Graph (you will need to authorize the app using the 'Get access token' button there first), which might help you see if the data you want is available using that route. Click around a bit or type your page's ID in the input field there to get a bit of information. I haven't been able to find the Likes for a page using it yet though - if I enter a <pageid>/likes, I get an empty list, although I am able to get a list of people liking a specific post by following <pageid>/posts. 82.75.188.107 (talk) 18:27, 23 July 2011 (UTC)

relief map

i wasn't sure where to ask this question but is there any software by which i can make (imaginary) relief maps, very easily in a simcity like way?(i want it for a sci-fi story)--Irrational number (talk) 14:00, 23 July 2011 (UTC)

The scenery generator and fractal landscape articles list a few programs that can do this. -- Finlay McWalter ☻ Talk 14:04, 23 July 2011 (UTC)

Connecting subwoofer to receiver

I've recently upgraded from a plasma TV-based setup to a home cinema with projector, but I'm having trouble connecting my old subwoofer to my new receiver (it is this model). My subwoofer seems to use the same connection as my other speakers (here's a pic]) but there doesn't seem to be a port for it to connect to. Would I have to use some kind of adapter? doomgaze (talk) 15:20, 23 July 2011 (UTC)

Your receiver has a line-level output for the subwoofer. You can use a powered subwoofer (that is, one with a built-in amplifier) with it. If you want to use your existing (non-powered) subwoofer, you'll need an amplifier to drive it. Try searching the web or your favorite shopping sites using "mono subwoofer amplifier" and variations of it. --98.114.98.196 (talk) 16:38, 23 July 2011 (UTC)

And you might find you can get a more modern sub-woofer for less than the amplifier will cost. That's what I did. I got a decent 2.1 system (right speaker, left speaker, and powered mono sub-woofer) for $30. StuRat (talk) 18:11, 23 July 2011 (UTC)

Mm I was going to make that observation too, looks like I'll just replace the subwoofer. Thanks guys, doomgaze (talk) 18:33, 23 July 2011 (UTC)

Missing edit links in Reference Desks

Wikipedia seems to a longstanding problem with sporadic disappearances of page and section "edit" links. Right now none of the Reference Desks has any edit links, either for the page or for individual sections. (I'm relying on a workaround to post this.) Does anyone know what the cause of the problem is? --98.114.98.196 (talk) 17:25, 23 July 2011 (UTC)

It seems to only be a problem for anonymous I/P's, like yourself. I suspect it's the lowest level of protection, to prevent spambots from plastering these pages with ads. You can sign up with Wikipedia for free, to avoid this problem in the future. StuRat (talk) 18:02, 23 July 2011 (UTC)

There's zero evidence for that and it seems rather unlikely since the foundation doesn't tend to play nasty tricks. All evidence suggests it's a bug that no one has tracked down. The reason it only affects anons is likely because only they use the cached version. Nil Einne (talk) 18:56, 23 July 2011 (UTC)

It's still happening here too. Nothing seems to come of the threads on Village Pump either. Someone suggested filing a bugzilla report, I've no idea how to do that though. 82.43.90.27 (talk) 21:22, 23 July 2011 (UTC)

I do like to call it as "fake protection" or "spoofed/cloaked protection". That means, the page seems to be protected and you cannot edit it, but actually can. Testor Ploa (talk) 04:05, 24 July 2011 (UTC)

No, no, it is not true that you cannot edit a page if the edit links of sections are not visible (simply press the Edit tab at the top), and missing edit links do not only affect anons. See Wikipedia:Purge for the cause and the solution. --Espoo (talk) 16:08, 8 October 2011 (UTC)

Should routers make faint noises?

Should DSL routers with a DC input make very faint high pitched noises, audible only when you put your ears against them? What causes the to make this noise? Bahr456 (talk) 21:05, 23 July 2011 (UTC)

I often hear the flyback transformer in old television sets, and very often hear capacitors audibly squealing inside the switching power supply in a lot of small electronics. I particularly noticed a ~15 kHz squeal on the power supply of my old Linksys 802.11b wireless router. Although such noises indicate a power supply whose design or manufacturing-tolerances were "imperfect," they rarely indicate a failure or imminent problem. "Theoretically," acoustic resonance in a capacitor may reduce its expected lifetime, but I've never seen this in practice.

The root cause, in many cases, is a sort of 'piezoelectric effect' In the power supply capacitor. A signal is passing through the cap, which by design should (usually) be outside the audible range - say, 1 MHz, for switch mode power conversion. Due to imperfect design, some signal may leak into an audible band. Then, because the capacitor dielectric is subject to a mechanical force due to electrostatic attraction, the acoustic frequency electromagnetic signal can cause an acoustic vibration of the capacitor dielectric. This can cause a faint audible buzz, hum, or squeal.

There are probably dozens of other possible root causes for faint squeals or hums in your router, but this one seems most common in my experience. Nimur (talk) 04:16, 25 July 2011 (UTC)

screen recording device

Taking note that the people here are experienced with computers, could you please recommend to me some free software that records what you do on the screen that does not slow down the computer significantly nor advertise itself in the playbacked video? Thanks. --Thebackofmymind (talk) 21:32, 23 July 2011 (UTC)

CamStudio or VLC would be my recommendations. In VLC to record the screen go Media - > Convert / Save -> Capture Device - > Capture Mode -> Desktop. Both programs require some processing power to operate, which may slow down your computer. I don't think there's any way to work around that without upgrading your computer. AvrillirvA (talk) 23:15, 23 July 2011 (UTC)

Check out Comparison of screencasting software.

APL (talk) 06:11, 24 July 2011 (UTC)

To avoid a significant slowdown, you'd need a very low frame rate and/or resolution/color depth, or to give up on using the computer to record itself and use an external video cameras instead (or maybe clone the images going to the monitor and send half to another computer's video input, and have it store the images). StuRat (talk) 06:16, 24 July 2011 (UTC)

July 24

Speech recognition

I used a speech recognition software to recognize the lyrics of a song and the result was incorrect. Any idea? Testor Ploa (talk) 04:01, 24 July 2011 (UTC)

Not particularly surprising. As our speech recognition article indicates, this works best in the context of a narrowly-defined field, where the vocabulary is small, and the semantics clear. Song lyrics are almost the polar opposite of this. Time flies like an arrow, fruit flies like bananas, and my love is like a red red rose... AndyTheGrump (talk) 04:36, 24 July 2011 (UTC)

Time flies like an arrow... but we can decelerate it. Testor Ploa (talk) 04:51, 24 July 2011 (UTC)

Even people with good hearing have difficulty figuring out song lyrics. See mondegreen.--Shantavira|^{feed me} 05:38, 24 July 2011 (UTC)

I'm afraid this is just a limit of the technology. Even with no background noise (musical accompaniment counts as 'noise' in this context) speech recognition is far from flawless. APL (talk) 06:17, 24 July 2011 (UTC)

That's a good point. The human auditory system is readily and instinctively able to distinguish language from background noice/musical overlay and process it effortlessly. On the other hand, computers so far struggle immensely with this distinction and processing. Simply, a computer can't do any better making out the lyrics of some recording than your ear can.--el Aprel (^facta-_facienda) 21:53, 24 July 2011 (UTC)

Chances of tracking down attempted SQL injection

OK so i did a stupid think i tried "how to hack" youtube video and tried to hack as an Admin onto a website. After an "Admin" username and string [1'or'1'='1], this message in red letters popped up that this security breach attempt was forwarded to their IT department.

I was in firefox, with private browsing enabled (similar to Google incognito, http://support.mozilla.com/en-US/kb/Private%20Browsing), and had Tor, which allows me to connect to multiple anonymous servers (bouncing your communications around a distributed network of relays). What are the chances I can get tracked down for this?--DSbanker (talk) 04:11, 24 July 2011 (UTC)

I suspect this will depend very much on the website you were trying to hack. If it was some random forum, you may very well get away with it (scary warnings don't necessarily mean much), but if it was the CIA, don't make any long-term plans. But why would you think that YouTube was a sensible place to look for help on this in the first place? Anything there is more or less certain to be either wrong, simplistic, or just plain useless. AndyTheGrump (talk) 04:22, 24 July 2011 (UTC)

It was actually the website of a midsize business in another state.

i am 15 years old, and yes what i tried was stupid. But i did plan for this scenario to come up and planned to be untraceable, as i am beginning learning python and etc. The only problem, i connected to Tor from a home IP address (stupid) Correction: this should be called "Chances of tracking down attempted SQL injection?"--DSbanker (talk) 04:26, 24 July 2011 (UTC)

It isn't just stupid, it is wrong. Breaking into websites is as bad as breaking into houses. If you develop criminal habits at the age of 15, you are going to find it hard to unlearn them. Give it up! There are better ways to get your kicks. Looie496 (talk) 05:43, 24 July 2011 (UTC)

If you were properly using TOR, I think the chances of them tracking you down would be pretty low. Even without TOR they'd need to contact the FBI who would need to get a warrent to your ISP's records and then confiscate your computers to verify that it was you and not someone controlling your machine remotely. Tor's biggest known vulnerability requires a number of "bad apple" nodes hidden within the network. I'm sure a number of law enforcement agencies have done this, but I don't think they'd "out" them for such a juvenile and unsuccessful attack.

To be honest, the fact that they've got an error message specifically designed to be scary makes me think that they get a lot of people trying it. So I wouldn't lose too much sleep over it if I were you. APL (talk) 06:07, 24 July 2011 (UTC)

I'm a bit annoyed here. We ought not to be assisting people with criminal activity, or helping people to avoid facing the consequences of criminal activity. Looie496 (talk) 17:31, 24 July 2011 (UTC)

I'm just asking something here. I am not gna be trying it again.--DSbanker (talk) 23:59, 24 July 2011 (UTC)

It's not clear that the OP violated any laws (even if he/she had gotten in, cybercrime is a really problematic area, esp. with mere intrusion into a private server). We're not assisting anything illegal in any case. We're telling them that they aren't going to be tracked down anytime soon for such an amateurish little thing. Which is undoubtedly true.

I will point out that one of the first things I did when learning about SQL injection (which I started SQL programming) was to try a rather simple injection on a website I was using, and was shocked to find that it was wide open exposed. I sent the sysadmin an e-mail and they patched it up. Nobody tracked me down to arrest me. It was a good lesson. --Mr.98 (talk) 01:33, 25 July 2011 (UTC)

...and what would the OP have done if their hack had been successful? People have been arrested and convicted to prison terms for hacking. Like Looie, I don't think we should encourage criminal activity. Astronaut (talk) 15:01, 25 July 2011 (UTC)

I didn't get in, and I don't plan to do anything of the sort again. I was just going to see if what I saw on YouTube worked. I was just fooling around, which was stupid. Il confine my ideas of such activities to theory.--DSbanker (talk) 15:43, 25 July 2011 (UTC)

If you want to become an ethical penetration tester, want to become a sysadmin or are just interested in the field, practice on 'intentionally vulnerable' systems like OWASP WebGoat or Metasploitable, which are legal training kits intended for training pentesters, security consultants and security-minded sysadmins, running in an isolated virtual machine on your own computer. Never practice on someone else's live system without permission. CaptainVindaloo ^{t c e} 16:21, 25 July 2011 (UTC)

Hey thanks for info on that stuff! really appreciate it.--DSbanker (talk) 16:41, 25 July 2011 (UTC)

A command for checking how much memory a program uses during its runtime (in Linux)...

Hi! I'm a bit new to using Linux and the command-line, but I'm already falling in love with it. I have a question though: if I want to find out exactly how much time a program takes to execute, I can simply use the very convenient time utility. Is there a corresponding utility for memory? Like, you type something like "memory something", and it lists the maximum amount of memory "something" needed during runtime? The reason I want this is just as an easy way to check if some optimizations to a program I'm making is actually working. I realize that there are much better ways to do it, but I just want a very quick and dirty way to get some idea about it, much like how the time-command gives you a quick and dirty way to find out if your program becomes faster. 80.216.71.133 (talk) 07:45, 24 July 2011 (UTC)

valgrind, by default, provides a basic summary with the info you're looking for. Moreover valgrind can report all kinds of stuff, to an overwhelming level of detail. Incidentally, once you feel "time" isn't giving you enough detail of where the time is being spend, gprof is very informative. Equally strace (which shows system calls and their arguments) and ltrace (which does likewise for library calls) can be very informative. -- Finlay McWalter ☻ Talk 10:01, 24 July 2011 (UTC)

To be on the this topic, is there one more detailed (for Windows) than Task Manager in Windows (other than Sysinternals) that is rather cheap on memory resources? General Rommel (talk) 11:05, 24 July 2011 (UTC)

Purify is very good. -- Finlay McWalter ☻ Talk 11:28, 24 July 2011 (UTC)

How about top? Also, vm_stat on some Linux/Unix platforms, though that doesn't break memory down by process, it does show different types of page allocations, which may help diagnose performance issues. Nimur (talk) 03:26, 25 July 2011 (UTC)

Games that spontaneously alt-tab

I enjoy the game Heroes III. (Yes, even though it's old.) Once in a while, though, it will dump me to the desktop. I can easily alt-tab back to it and continue where I left off, but recently I've been trying to find out why it happens - checking for malware, turning off various services and so on. Does anybody know, is this:

• A known bug in Heroes III,
• A known side-effect of any specific spyware,
• A known problem with some part of Windows XP?

I've sometimes observed the same thing in other games, though that might be coincidence. I've never known it happen in any of the various art programs and IDEs I run, only while playing games - and not very often. It might be related to programs that run full-screen, although I've never noticed it affect Blender.  Card Zero  (talk) 11:40, 24 July 2011 (UTC)

A guess: when you run old games in fullscreen mode, often they have to switch resolutions and video modes and etc. as they segue between different parts of the game (e.g. menus, the main game, whatever). I seem to recall on my old computer that sometimes these transitions would bug out or fail or something. Does it happen while just playing, or is it something that happens when switching between different resolutions? Does it happen while you are actively playing, or when you've not done anything for awhile? --Mr.98 (talk) 12:24, 24 July 2011 (UTC)

Good thought, but no - today it happened just before some AI-controlled vampire lords flew over my castle wall to attack something, which doesn't involve any sort of switch between screens. I have a vague feeling that it might always happen just before a sound is played, and so I am suspicious of my sound driver, but I don't find the idea very plausible (lots of sounds are played in the course of a game, and why would the sound driver suddenly dislike one of them, and ... so I'm just being superstitious really). I think it can happen while the game is idling, too.  Card Zero  (talk) 12:34, 24 July 2011 (UTC)

Could it be a different application (eg messaging) trying to get your attention, which would switch you out of the fullscreen game ? Unilynx (talk) 14:33, 24 July 2011 (UTC)

do you know how to check the event log? There might be a clue there. Vespine (talk) 05:06, 25 July 2011 (UTC)

I've noticed this behaviour with Windows Notification complaining about firewall being turned off or something similar. Sometimes the notification does not popup in a window but in the taskbar which is sufficient to move focus away from your game to the desktop. Sandman30s (talk) 08:38, 26 July 2011 (UTC)

laptop booting

my laptop bios wont accept the os which i put...aft pressin enter wen it prompts to press any key for boot it shows a blinking cursor with a black background.....help me out pls.... — Preceding unsigned comment added by 59.161.181.224 (talk) 14:28, 24 July 2011 (UTC)

What OS are you trying to boot? Can you boot any other OS? This problem generally means that the bios can't locate or read the boot commands, but there are many possible causes, including hardware failures, disk corruption, or an incorrectly set up boot sector. Looie496 (talk) 17:25, 24 July 2011 (UTC)

wget article history

How would you use wget to output all the IP contributors to let's say the Example article to a text file ? Drogonov 19:42, 24 July 2011 (UTC)

I don't think that's a task wget could do on its own. Wget is just a download program, it can download the history page but you'd need to use some other program to process it, extract ip addresses, and output them to a text file. Maybe something like grep 82.43.90.27 (talk) 22:20, 24 July 2011 (UTC)

As long as Drogonov didn't need to do anything more, wget+grep should be enough. But if the real goal is to do more processing (e.g. to retrieve and analyse the contributions of the IP contributors) then scraping the HTML becomes a pain. The Mediawiki API (and the accompanying wrapper libraries for various programming languages) makes doing this kind of thing much, much easier. -- Finlay McWalter ☻ Talk 23:44, 24 July 2011 (UTC)

Linux distribution system requirements

I have an old Windows 98 second edition PC that is idling and I'm thinking about trying out Linux on it. Is there a list of hardware system requirements for the older Linux distributions? In particular, I'm considering Ubuntu. My PC uses Intel 82443BX Pentium (r) II processor with 128 MB Ram & 19 GB hard disk. Thanks. Axl ¤ [Talk] 20:24, 24 July 2011 (UTC)

That's well below the recommended requirements for Ubuntu Desktop. A lightweight Linux distribution like Puppy Linux should be okay. -- Finlay McWalter ☻ Talk 20:30, 24 July 2011 (UTC)

But if you intend to use the machine only as a (slow) server, it's just within the requirements of the Ubuntu Server CLI. -- Finlay McWalter ☻ Talk

Finlay, thanks for your answer. Is even the oldest version of Ubuntu too advanced for my machine? What about Windows XP? I think that Windows XP should work, right? Axl ¤ [Talk] 21:28, 24 July 2011 (UTC)

Running an older-than-current version of Ubuntu is a bad idea; only one older version is still supported, and it's not that old. You're talking about a machine that's at least 13 years old; asking it to run anything other than a very low-end system isn't practical. If you want to eke out a few more years of minimal functionality from this thing, use Puppy Linux. It might just run XP, but XP licences are hard to get and would be wasted on this thing. Equally any Linux on this thing is going to be a basic experience at best. If you're curious about what a modern mature and feature-rich Linux experience is like, but don't want to commit a nice new-ish machine, you can install Ubuntu on Windows (where it's kinda like an application) using Wubi (which comes on the Ubuntu install disk); this won't damage your existing Windows install. As to the Pentium II - frankly I'd either put this thing in the bin or I'd get it running Win98 nicely and pack it up carefully and put it in the attic, and in 20 years it'll be worth donating to a museum. -- Finlay McWalter ☻ Talk 21:53, 24 July 2011 (UTC)

Okay, thanks Finlay. Axl ¤ [Talk] 22:05, 24 July 2011 (UTC)

You could try a LiveCD to try out something like PuppyLinux without installing it. See List_of_live_CDs#Linux-based. 2.101.4.222 (talk) 09:36, 25 July 2011 (UTC)

Yeah, I'll try one of the lightweight versions from USB, maybe Lubuntu. Thanks. Axl ¤ [Talk] 18:24, 25 July 2011 (UTC)

See also Lightweight Linux distribution and List of Linux distributions that run from RAM. 2.97.216.222 (talk) 21:03, 25 July 2011 (UTC)

July 25

Does logging in enhance access to this desk?

Hi I noticed that when I am not logged into Wikipedia, I can only see up to July 21, but when I am logged in, it takes me to the current forum. Is this supposed to happen--DSbanker (talk) 00:01, 25 July 2011 (UTC)?

No. —Jeremy v^_^v ^{Components:V S M} 00:09, 25 July 2011 (UTC)

We have previously noticed that (either by design or by accident) that many users who are not logged in see old, cached versions of the reference desks. That may also entail that the page appears read-only. If you're curious about details, search this page's archives for "caching" and "wikipedia" - if you need help finding some of the numerous prior detailed discussions, I or one of the other refdesk regulars can probably track down the archived discussions. Nimur (talk) 04:24, 25 July 2011 (UTC)

Some of the archived discussions;[1][2][3] [4]There's also a thread further up this page about it [5] and some threads from Village pump;[6][7]. The workaround at the moment is to purge Wikipedias server cache, see WP:Purge for how. This will force the current version of the page to appear, and you may have to keep doing it as for some reason pages often revert back to the out of date versions. Something really needs to be done about this entire situation, it has been going on for ages now AvrillirvA (talk) 10:40, 25 July 2011 (UTC)

Yes, this is happening to me as well, a lot of old revisions of pages are appearing, and as read-only. 80.123.210.172 (talk) 14:50, 25 July 2011 (UTC)

Ideal programming language(s) for beginning bioinformatics

I am a high school sophomore and visited a professor in the molecular biology sciences who is also an expert programmer. (He builds robots, biochips, and a bunch of other cool gadgets.) In discussing other things, he urged me to learn Python programming, and now im very interested in computer science, and progressing rapidly. I know Python is a powerful language for its simple syntax. But if I want to go into bioinformatics (especially to use the tool http://www.ncbi.nlm.nih.gov/BLAST/) and computer programming in general, maybe even study cybersecurity, is it an ideal language to start with? or is C/C++ a better choice?--DSbanker (talk) 15:33, 25 July 2011 (UTC)

In the long term, it doesn't make any difference. The skill you hope to acquire is programming; it's a bit like driving - you can learn to drive in a mini or a van and then drive anything in between, with a skill that's a head-start for learning to ride motorcycles or drive big-rig trucks. Any decent programmer can change to another language without a great struggle. -- Finlay McWalter ☻ Talk 16:11, 25 July 2011 (UTC)

Are there programming languages that would be especially bad choices for a beginning programmer; either because they are especially difficult to learn or eccentric in their approach and thus not easily transferable to other languages? Wanderer57 (talk) 16:40, 25 July 2011 (UTC)

Yes. There are many. Mumps is one that I like to pick on for being a terrible language to learn. Then, there are ones that are languages that are great for their intended purpose, but trying to use them as a general all-purpose language is a mistake, such as Lisp, Perl, or QBasic. -- kainaw™ 16:45, 25 July 2011 (UTC)

Lisp is definitely not a special-purpose language! Because of their macro systems, Lisp-like languages are perhaps the most general-purpose languages possible. A number of schools teach Scheme (a Lisp-derived language) as a first language because they're nice and simple, yet powerful. Paul (Stansifer) 18:46, 25 July 2011 (UTC)

This is just proof that any claim that anyone makes in the realm of computer science is certain to be met with contradiction without sufficient explanation. Scheme, as mentioned, is a dialect of Lisp that reduces emphasis on list processing and increases emphasis on minimalism and extendability. As such, it is more general purpose than Lisp - which is why I didn't include LispScheme in a very short list of programming languages that are primarily used as specialty languages. Similarly, I didn't include ML, which is my preferred dialect of Lisp. -- kainaw™ 19:41, 25 July 2011 (UTC)

Did you mean to say you didn't include Scheme or 'it' (i.e. referring to Scheme)? Nil Einne (talk) 09:52, 26 July 2011 (UTC)

There's a claim (which to my mind is a total myth) that the first language you learn somehow warps your mind (like some kind of neuroplastic Whorfian fugue) and that if you learn the wrong language (which is whatever language industry actually wants right now, and thus is unfashionably associated with drab accounting programs) you're forever scarred. If this were true, programmers of my age, who learned on a motley collection of BASIC, 8-bit assembly, forth, and some pascal, should by rights be gurgling imbeciles, our code neither (as the song would have it) functional nor elegant. In practice there's mostly a continuum from the mechanical end (VHDL, asm, C) through the procedural (pascal, python, javascript, java, perl) to the functional (ml, haskell, scheme) and logical (prolog). Although most people end up making their living writing C++ or Javascript or the like many universities try to start their CS (and sometimes EE) people off with lisp or haskell (and I've heard of places, at least a decade or so ago, still starting people with prolog). It is a bigger jump from Haskell to C than from Python to C, but clearly plenty of people of reasonable intelligence graduate from one to the other without their minds exploding. A friend of mine worked for decades in Cobol, a language decried by the fashionistas as everything that's wrong with the world, but in practice the programs he was producing did complex distributed time-sensitive operations; the programs probably looked rather ugly, but the ideas they represented were beautiful. There are some wilfully abstruse ghetto languages, but in general any language of moderate maturity, whose creators designed it to get stuff done and not just to make a point, should be just fine. -- Finlay McWalter ☻ Talk 17:08, 25 July 2011 (UTC)

I don't know why I didn't think to mention this above, but I work in bioinformatics as a programmer. The language that I use about 90% of the time is PHP. I could use Python or Ruby or any scripting language. I use PHP because many of the libraries that I had access to when I started where in PHP and I'm not in the mood to rewrite them. The reason for using a scripted language instead of a compiled one is that much of the programming is based on some theory that some doctor has. So, a quick script is written to compare this, that, and something else and pump out a CSV file that the doctor can play with in Excel. On a day when I'm in a good mood, I'll even dump a PDF report with pretty graphs. The scripts are one-time use, so I don't have any need to compile and store a lot of executables. The runtime hit for scripting isn't important. I just start the script and move on to the next project. When the script eventually ends, I send the results off to the doctor. -- kainaw™ 19:45, 25 July 2011 (UTC)

I think starting with Python is perfectly fine. I wish it was around when I started programming. Well, it was around when I really started learning programming, but not to the point of being widely used. After Python, I'd look into Java. That's another language school like to use as a starting language, and it has a lot of usability for cyber-security. --Wirbelwindヴィルヴェルヴィント (talk) 00:09, 26 July 2011 (UTC)

A lot of the bioinformatics grad students and faculty I know like to use the R statistical programming language, particularly for when they use our HPC clusters. I agree that Python is a great way to get into programming, though, particularly since SciPy is almost as fast as the Matlab toolboxes that perform the same kind of operations. -- JSBillings 00:22, 26 July 2011 (UTC)

It depends with whom(projects are generally written in the same language) and with what you'll be working with. There are beginning books specifically for bioinformatics:

• Robert Gentleman (2009). R programming for bioinformatics. CRC Press. ISBN 9781420063677. Retrieved 25 July 2011.
• James D. Tisdall (2001). Beginning Perl for bioinformatics. O'Reilly Media, Inc. ISBN 9780596000806. Retrieved 25 July 2011.
• Jon Ison; Ison/Rice/Bleasby; Alan Bleasby (1 March 2008). Bioinformatics Programming with EMBOSS. Cambridge University Press. ISBN 9780521607247. Retrieved 25 July 2011. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• Mitchell L. Model (23 December 2009). Bioinformatics Programming Using Python. O'Reilly Media, Inc. ISBN 9780596154509. Retrieved 25 July 2011.
• Ruediger-Marcus Flaig (2008). Bioinformatics programming in Python: a practical course for beginners. Wiley-VCH. ISBN 9783527320943. Retrieved 25 July 2011.
• Harshawardhan Bal; Johnny Hujol (2007). Java for bioinformatics and biomedical applications. Springer. ISBN 9780387372358. Retrieved 25 July 2011.

Depending on how intensive the task, you may need to learn assembly for CPU and GPUs which are increasingly being used such as CUDA.Smallman12q (talk) 01:48, 26 July 2011 (UTC)

Why would you need to learn GPU assembly? Isn't the whole point of CUDA and similar APIs like DirectCompute and OpenCL to take away the need for such low level programming? Nil Einne (talk) 09:49, 26 July 2011 (UTC)

Such a discussion is outside the scope of this thread. See Programming language generations, Programming paradigm, as well as Low-level programming language and High-level programming language.Smallman12q (talk) 20:45, 26 July 2011 (UTC)

None of those suggest CUDA is assembly. Okay further research suggests PTX can be considered a part of CUDA and can arguably be considered assembly. But even then my impression supported by e.g. [8] [9] is that assembly programming including PTX programming for GPGPUs is commonly not recommended because, other then the fact most people can't do better the compilers which is common with x86 and most CPU assembly programming, Nvidia and AMD don't release the information about their hardware necessary to mean it's likely you can perform better. (I believe Close to Metal was arguably assembly but it's long dead so it doesn't seem wise to learn it.)

And my impression from what people have said in the RD is even on the purely gaming GPU (rather than GPGPU) level, most graphics programmers are moving away from bothering with things like ARB (GPU assembly language) although I believe it wasn't unheard of in the past.

Of course if you are writing for a specific hardware subset that you intend to operate your code with, you don't have so many of the considerations that people trying to write code for others to execute have but I'm still not convinced there is much point learning assembly for GPGPUs particular for someone in the field of bioinformatics, at least not until you find a reason why you need it.

Nil Einne (talk) 18:08, 27 July 2011 (UTC)

What is bioinformatics?

This question is a followup to the previous one.

I looked up bioinformatics and read: "Bioinformatics (i/ˌbaɪoʊˌɪnfərˈmætɪks/) is the application of computer science and information technology to the field of biology."

To me that field is as wide as all outdoors. Is it really so broad as that? Thanks. Wanderer57 (talk) 03:07, 26 July 2011 (UTC)

Well, no. I think it would be more accurate to say that it is the application of database technology to biology. That might be a bit too limited, but the other is certainly too broad. Looie496 (talk) 03:22, 26 July 2011 (UTC)

Bioinformatics is merely the overlap between Biology and Computer Science (specifically Information Technology). About 80% of the time, it applies to the use of computers to advance DNA research. About 15% of the time, it refers to health informatics - using computers to advance health research. About 5% of the time, it refers to something that has nothing to do with biology or computer science. There is an internal problem in Bioinformatics in that the DNA researchers think that DNA research is all there is to bioinformatics and they get angry when they see something like a population study on diabetics in Canada. But, for those outside the field, it is just using computers to handle a large about of data that has something to do with biology. It is a bit specialized. For example, anyone with good programming skills and database knowledge could do my job, but they would do it poorly. Half of my "computer programming" job is fully understanding medical terminology and coding. No doctor wants to sit down and cover every ICD9 code that may imply cardiovascular disease in some report he's asking for. He just wants to say "I want CVD patients" and get his report. -- kainaw™ 18:08, 26 July 2011 (UTC)

Thank you. So, for example, if a team is on a huge development project to create a system to capture patient's medical records from anywhere they could be created, store them, and allow doctors and hospital to access them, is that bioinformatics? Wanderer57 (talk) 18:40, 26 July 2011 (UTC)

It becomes health informatics when you do research on the data, which is a subset of bioinformatics. Collecting data from a distributed heterogeneous source is computer science and, strangely, a lot of people keep thinking that this is a new field of study even though it has been implemented many times since the 70's. -- kainaw™ 18:46, 26 July 2011 (UTC)

Thanks again. I don't see "Collecting data from a distributed heterogeneous source" as new.

I'm wondering though about a very large system with very complex data. Say a system with the scope to absorb people's medical records from a wide variety of sources, and to make the information readily available in very useful forms (eg, a stranger is brought into a hospital in a state of collapse, as they pass a scanner the system identifies them using an implanted microchip, a query with the patient ID and the symptom "collapsed" is fired off, and a reply is fired back that starts with anything in their history that might be relevant to a collapse.) (Scalable to a population of say 15 million people.)

Is that new? Is that a big breakthrough waiting to happen? Or is it already in use? Wanderer57 (talk) 21:58, 26 July 2011 (UTC)

The capability for this has existed since databases came to be. Some examples would be Google Health, Microsoft HealthVault, IBM Healthcare, Oracle Health Information Exchange. Aside from privacy concerns, the technology is heavily encumbered by patent litigation.Smallman12q (talk) 01:17, 27 July 2011 (UTC)

It isn't new. I've been doing it since 2003. See http://oquin.musc.edu if you want to read about one way to make it work. The primary problem is privacy. Then, you have buy-in from the doctors. Then, you have an even worse time getting buy-in from the clinic's IT staff. Then, you have the relatively simple task of gathering and normalizing the data. -- kainaw™ 12:27, 27 July 2011 (UTC)

Problem synching Google Calendar & Android phone

I have an Android phone, and use Google Calendar (which I had been using online for some time before getting the phone). Now, most of the time it synchs fine, but twice now I've found that appointments are disappearing from the calendar as seen on the phone (they are still on the calendar online). What might cause this, how can I stop it happening, and most importantly is there a way to make the phone pick up the events again easily? Thanks. DuncanHill (talk) 19:46, 25 July 2011 (UTC)

On my phone, in calendar, I hit the option button, select more, select calendars, and I can see a sync/visible icon next to each one. Then, I can set which ones are synced and which are visible. I can also see if they are in fact synced. Are the missing events from an unsynced account? -- kainaw™ 19:57, 25 July 2011 (UTC)

No, they are from calendars which it says are synched (they've got a tick in the bx next to their names). DuncanHill (talk) 20:01, 25 July 2011 (UTC)

After using Windows, Ubuntu cursor breaks

I dual boot my laptop with Ubuntu 11.04 and Windows 7. I use the Ubuntu partition a lot more, because I prefer it, it runs faster, it has all my files on, etc. But sometimes I run Windows-specific software/games, and have to go back to Windows 7.

However, every time I use Windows, the next time I load Ubuntu, the cursor jumps randomly around the screen and I have to restart using Ctrl+Alt+Delete or the button on my laptop. After a restart, it works fine.

This is an annoyance, and I wondered if anyone had any idea what causes it and/or how to fix it. Dendodge _T\^C 19:59, 25 July 2011 (UTC)

It seems likely to be some sort of problem relating to the pointer device settings. What sort of laptop in it, and what sort of pointer does it have? (Touchpad?) Looie496 (talk) 05:57, 26 July 2011 (UTC)

It's a Dell Inspiron 1545 with a normal touchpad thingy. As far as I can tell, it's an ImPS/2 ALPS GlidePoint. Dendodge _T\^C 23:20, 26 July 2011 (UTC)

This is a known bug, see this bug report. Apparently what is happening is that the touch pad is recognized as a mouse, and therefore handled incorrectly. There is apparently no proper fix yet, but one of the comments includes a workaround in the form of a Python script you can download and run when the problem occurs. Looie496 (talk) 01:09, 27 July 2011 (UTC)

IGMP and PIM

Can someone please present a brief explanation of the roles of IGMP and PIM in a network and when would one or both be used? The respective articles do not relate each other. Thanks in advance. 81.193.153.78 (talk) 22:26, 25 July 2011 (UTC)

July 26

privacy & google maps street view

Looking at

this street view on Google Maps, I just see some ordinary boring houses; then I click on the white arrow to move further in the direction at the right side of the picture and see this ordinary-looking house, and click on the arrow again, and there's nothing unexpected; and so on, but then this one starts to show something different, and here something's definitely not in focus, and similarly here, and here, that's coming to an end, but not quite yet, and the next building is not concealed, but we're not past all that yet, and now we've moved on, and we're back to normal here.

Is this

• a problem with focus; or
• done deliberately for the sake of privacy because whoever lives there demanded it; or
• something else? Michael Hardy (talk) 01:34, 26 July 2011 (UTC)

Quite a few Germans didn't want their houses on Streetview: http://searchenginewatch.com/article/2050481/244000-Germans-Demand-Removal-of-Google-Street-View-Imagery Unilynx (talk) 05:13, 26 July 2011 (UTC)

I see. Some time last year I noticed that I could get street views for a city in Spain (I don't remember which one) and for some parts of Hamburg but not others. I thought that more of Hamburg is now visible in this way than was a year ago, and the article you link to seems to confirm that. Michael Hardy (talk) 15:04, 26 July 2011 (UTC)

The Streisand effect may be of interest to you as well. Dismas|^(talk) 05:28, 26 July 2011 (UTC)

Reliable Power Supply Unit

I'm planning on building a computer that requires 280W of power (actually more like 200W, but I like to be conservative). I'll be using this computer at a site with unreliable power produced by a small generator. I desperately need a reliable power supply unit that won't fail under larger-than-normal fluctuations in the amplitude, frequency, etc. of the input power. Can anyone recommend a PSU that has comprehensive protections built-in, and that produces a nice, clean output voltage despite "dirty" input power? --140.180.16.144 (talk) 05:24, 26 July 2011 (UTC)

Such a job (which is often called "power conditioning") is often done with an external uninterruptible power supply. You can find small single-PC versions (which also give a couple of minutes of uptime in a total power failure mode) for a very modest fee. A few companies produce PC PSUs with built-in UPS functionality, but unless you're very short of space indeed, I'd go with a simple external one. -- Finlay McWalter ☻ Talk 11:24, 26 July 2011 (UTC)

You'll want to pay attention to the offline / line-interactive / online distinction in uninterruptible power supply. Offline is the cheap and ubiquitous device, but does nothing to power fluctuations. Line-interactive can help with power fluctuations as long as they are not too rapid; these UPSes exist for the consumer market, but you'll need to pay attention that you buy one of these rather than an offline one. Online is the best for dirty input power, but these tend to be high end, high power professional devices - I have never seen a home/small office model for sale (not that I have looked very hard.) 88.112.59.31 (talk) 15:28, 26 July 2011 (UTC)

Pulling up a nickname history on IRC

I was told that /who is the command to pull up the history of all usernames used on a hostmask. I tried that on my own; didn't work. (Someone else managed to succeed on that one, however.)

It should say "Nicknames seen on (hostmask): (list of all nicknames.)"

What exactly is the command that I type to get this? Is it even a "/who?" --70.179.165.67 (talk) 05:30, 26 July 2011 (UTC)

I think you might be able to get this information with /whowas. ^Avic_ennasis @ 06:12, 24 Tamuz 5771 / 26 July 2011 (UTC)

Webpage with multiple scrollbars and no frames

Hi! I'd like to create a webpage which looks like this: http://i.imgur.com/iDoLl.png

I can't use frames(I'll be using AJAX on the site so more reason to have everything in one page because content on one page influences others. What's the cleanest way to do something like this?

A website which does something similar would be Google Reader. I'm a total noob with HTML and I'm not sure how they accomplished that.

Thanks! — Preceding unsigned comment added by Legolas52 (talk • contribs) 05:51, 26 July 2011 (UTC)

You just create a DIV element of a certain size, and then you specify overflow:scroll in its CSS style, and the browser will add scrollbars as necessary. The browser tries to avoid much horizontal scroll, so if you want more than a trivial mount of that, you need a horizontal object that is sufficiently wiiiiiiiiiiiiiiiiiiiiiiiide to force the internal "pane" to be wider than the DIV.

-- Finlay McWalter ☻ Talk 11:12, 26 July 2011 (UTC)

Yes, Mcwalter is correct. Read about the Overflow property here TheGrimme (talk) 13:10, 26 July 2011 (UTC)

But, some browsers do not support scroll overflow. I see truncated content in the above example, viewing this page on an iPad in Safari (though, if I know it is truncated, I can swipe to scroll it). On the other hand, I can zoom content on the iPad in ways that conventional browsers cannot, so I do not strictly "need" scrollbars on my divs. (If Finlay's CSS had not specified size in this way, I could have zoomed into the div). Use caution designing your webpage user interface, because it may be viewed on many different types of systems, browsers, and devices. The page will not always appear as you intended. Strict interpretation of the W3C guidelines for CSS overflow indicate this issue: if the user agent supports scrolling. Consider using overflow=auto to allow each browser to decide its layout for itself. Nimur (talk) 15:04, 26 July 2011 (UTC)

Additional discussion of the issue at StackOverflow - though I do not advocate all the solutions suggested there. I am philosophically predisposed to disrecommend JavaScript or JQuery for this purpose, as it amounts to browser-sniffing. Nimur (talk) 15:09, 26 July 2011 (UTC)

Is this sentence correct?

Moved to Wikipedia:Reference desk/Language#Is this sentence correct? as a far more suited desk for this question Nil Einne (talk) 09:43, 26 July 2011 (UTC)

Matrix multiplication in php using foreach loop

Please can u help me for multiplying two 3x3 matrices in php using foreach loop. — Preceding unsigned comment added by 14.97.130.154 (talk) 15:03, 26 July 2011 (UTC)

Please do your own homework.

Welcome to the Wikipedia Reference Desk. Your question appears to be a homework question. I apologize if this is a misinterpretation, but it is our aim here not to do people's homework for them, but to merely aid them in doing it themselves. Letting someone else do your homework does not help you learn nearly as much as doing it yourself. Please attempt to solve the problem or answer the question yourself first. If you need help with a specific part of your homework, feel free to tell us where you are stuck and ask for help. If you need help grasping the concept of a problem, by all means let us know. AndrewWTaylor (talk) 15:05, 26 July 2011 (UTC)

<?php
$a=array(0=>array(1,2,3),1=>array(4,5,6),2=>array(7,8,9));
$b=array(0=>array(9,5,4),1=>array(8,6,7),2=>array(5,4,7));
$c=array();
echo "a=";
print_r($a);
echo "<br>b=";
print_r($b);
foreach($a as $row=>$rowarray) 
{       
        foreach($rowarray as $col=>$val) 
        {
                $c[$row][$col]+=($a[$row][$col]*$b[$col][$row]); 
        } 
}
echo "<br> product=";
print_r($c)
?>

here is what i have tried but it is not working properly please help me out. — Preceding unsigned comment added by 14.97.130.154 (talk) 15:09, 26 July 2011 (UTC)

The formula for matrix multiplication is $c_{ij}=a_{i1}b_{1j}+a_{i2}b_{2j}+a_{i3}b_{3j}$. Your code implements a completely different formula. Looie496 (talk) 17:33, 26 July 2011 (UTC)

Matrix multiplication is performed by using a for loop inside of a for loop, not two foreach loops. You can make a mess of the code to force it into two foreach loops, but that would be rather idiotic. You end up with a slew if if-else statements that you wouldn't need if you just use for loops. -- kainaw™ 18:01, 26 July 2011 (UTC)

Note that our two foreach loops worked fine for matrix addition, because the matrix sizes must be identical. Matrix multiplication, though, can use matrices of difference sizes, so it definitely won't work for that. --Mr.98 (talk) 19:46, 26 July 2011 (UTC)

Update

Regarding my post here on July 17th with the heading "Malicious program in my computer" : the problem is solved. Surfcanyon seems to have been the culprit. After deleting its last remnants from my registry, the problem magically went away. A big thanks to those who gave advice to rid me of my problem—whether it helped or not, it was very much appreciated. Hooray! Hamamelis (talk) 16:02, 26 July 2011 (UTC)

For reference, the question was previously asked on 7/17: Wikipedia:Reference desk/Archives/Computing/2011 July 17#Malicious program in my computer —Akrabbim^talk 16:18, 26 July 2011 (UTC)

Another rsync question

When using rsync on a Fedora Linux system, can I do an identical folder move on both the source and the destination file systems (i.e. move the same folder from the same original place to the same new place) with a simple mv command and will rsync be happy with that, or will it mess up some kind of rsync configuration, meaning I would have to first move the folder on the source file system and then do a complete rsync update operation with the "delete files not present on source" option? JIP | Talk 16:35, 26 July 2011 (UTC)

Yes, providing the move on both ends produces identical results, rsync shouldn't need to do further work. rsync isn't like (many) version control systems - it doesn't keep around a persistent idea of what the remote filesystem should look like between runs. Note that, in some circumstances, people really do use a VCS to maintain a remote image, because (many) VCSs do have a concept of "move", which (as your question underlines) rsync doesn't. -- Finlay McWalter ☻ Talk 16:54, 26 July 2011 (UTC)

Great! The reason I'm asking is that I'm planning to move all my digital photo folders to a different subfolder, within the same file system. The move operation itself will only take a few seconds, but if I have to make rsync first copy the folder to the new location and then delete it from the old one, it will take hours, if not days. JIP | Talk 17:01, 26 July 2011 (UTC)

What could be causing wrong characters to appear?

I have a feeling if I go to the Village Pump with this they'll say it's the computer, not Wikipedia. But something is seriously wrong with this computer (not the one I'm using now, but a different one at the same library). In addition to being slow, it did this. The version on the right is what I actually typed. What happened on the left I don't know.Vchimpanzee · talk · contributions · 17:23, 26 July 2011 (UTC)

Malfunctioning keyboard. Looie496 (talk) 17:26, 26 July 2011 (UTC)

Well, I typed the correct characters and they did fine the next time.Vchimpanzee · talk · contributions · 17:46, 26 July 2011 (UTC)

A working keyboard but with the incorrect country defined in the PC's keyboard driver? For example, the "#" on a UK keyboard is close to the "[" and "]" characters on a US keyboard. Astronaut (talk) 12:52, 27 July 2011 (UTC)

I do know the characters appeared correctly when I retyped them. That computer had numerous problems (I'll report back if I find out more about what was wrong with it), though, and I gave it up. There's no reason for a UK keyboard as I am in the United States, and although the college has students from other countries, there's no reason it would have any UK keyboards.Vchimpanzee · talk · contributions · 18:25, 27 July 2011 (UTC)

C# questions

I've seen people in my company use constructs like these in C#:

object a = from list where (condition) select (field);

foreach (var a in list)

What exact benefit do these constructs give in favour of the following?

object a = list.Where((condition)).Select((field));

foreach (T a in list)

(assuming list is of type IEnumerable<T>)? JIP | Talk 18:54, 26 July 2011 (UTC)

They are syntactically equivalent. In the documentation, these keywords are calld "LINQ (Language-Integrated Query)" and are intended to be "easily-learned patterns for querying and updating data." Furthermore, it allows the programmer to use identical syntax for analogous queries to SQL, XML, and C# objects. In a sense, the intent was to promote data-querying from its status as a library function-call to a first-class language syntax construct. Nimur (talk) 19:20, 26 July 2011 (UTC)

July 27

How to download from public FTP?

There are some files here: http://mail.moshiz.com/ftp/misc/Worms%20World%20Party/data/User/Speech/Whoopsie/ which can be downloaded individually - they're custom soundfiles for a computer game. How do I access va FTP to download in one fell swoop? --92.28.85.56 (talk) 00:17, 27 July 2011 (UTC)

If you're running Firefox, the Down Them All extension is good for this kind of thing. -- Finlay McWalter ☻ Talk 00:23, 27 July 2011 (UTC)

(edit conflict) - There is no reason to believe that those files can be downloaded using FTP. FTP and HTTP are different communications protocols. Sometimes, the owner of a computer-server chooses to set up the system to deliver the same files using either/both protocols. But if not, there's no way for you (the user) to access the web server using FTP.

No worries, though: you can mass-download an entire directory over HTTP using wget, DownThemAll, or numerous other simple download managers. Nimur (talk) 00:25, 27 July 2011 (UTC)

It seems, in this case, that the server does also host ftp://mail.moshiz.com/ftp/misc/Worms World Party/data/User/Speech/Whoopsie/ and allows anonymous login (blank name and password). Watch the spaces in the URL; some FTP clients don't handle them well. They are spaces, not underscores or %20`s. Nimur (talk) 02:38, 27 July 2011 (UTC)

If you use a command-line FTP client then the "mget *" command should download all files in the current directory. CS Miller (talk) 08:17, 27 July 2011 (UTC)

Restoring Icons

Recently I downloaded a program reccomended to me off the internet, and though that porogram worked as well as could be expected, (though it did turn out to be not good enough for my intentions) it had some unfortunate results. After I had downladed it and installed it on my computer, over the following few hours I discovered that certain things on my computer were not as I remembered. My internet homepage and default search engine had both been changed to some entirely unrelated company. The homepage was easy enough to fix, and I can return to that any time I wish to search for something.

However, it is the third problem that I wish to ask you about today. You see, I often make use of Microsoft Works, particularly their Word Processor, however that day I discovered that the icons for all my files in that program had been changed to a rather simplified and low resolution image of a page, with the icon of the program I had just downloaded set in one corner. Meanwhile, these files, if sent to another computer, attempt to open in that program rather than in Works, which is quite annoying. I have tried anything I can think of to restore the original icons, without any success. I have gone so far as to delete everything at all related to that downloaded program, there is no sign of it left, other than on these icons, which remain unchanged. Before that, whenever I went to set the default program for the files to open in, though the default was always set to Microsoft Works, the list always opened with the other highlighted, even though it is a drawing rather than writing program, and with no commection to these files. Now it is gone, it no longer appears on the list, but of course the icons are still the same, other than the one on that list of programs, for some reason.

So, I come to to experts, to see if you know of any way I can get the original icons back for all my files.

And, whilst we are at it, I have recently transfered my allegiance to Open Office, but where my sister's computer shows those files with that company's icon, mine presents me with only with an image of the first page each time, is there any way of changing these as well?

79.66.98.118 (talk) 10:24, 27 July 2011 (UTC)

The first thing to try would be to reset the file associations. Specifics on how to do this can vary between versions of Windows, so if you could provide that information, it would be helpful. A system restore might help, if you know when you downloaded the offending program and can find a restore point prior to that. Revealing the name of the program could help us to help you. And for some unsolicited advice - prior to downloading programs from the internet, do some research to see if there is a record of problems. When installing any software, no matter where it came from, don't accept the default settings and carefully read each screen that is displayed. --LarryMac | Talk 12:20, 27 July 2011 (UTC)

Of course you could go through the file type assignments and reassign Works file types to the correct programs, but that won't remove the malware I suspect your computer is now infected with. Programs you download off the internet, especially those recommended by strangers, and especially especially those from a non-reputable source (file-hosting sites, torrents etc.) are sometimes infested with malware such as viruses, rootkits, password stealers etc. You computer is probably still infected. You can search the internet for removal advice perhaps by entering the '<name of new homepage> malware' into your favourite search engine. A frequently recommended product is Malwarebytes' Anti-Malware - it has a good reputation for dealing with many types of malware (and yes, I appreciate the irony in recommending you download another piece of software after my opening sentence). Astronaut (talk) 12:48, 27 July 2011 (UTC)

Steps to Post a Article

Hi, Can some body tell me steps to post a article in wikipedia.org? — Preceding unsigned comment added by Outsourcingrbts (talk • contribs) 13:54, 27 July 2011 (UTC)

indent fixed, which was caused by a leading space. See wp:your first article for how to create an article. For future reference, this reference desk is for help with computers and other IT equipment. The wp:help desk will gladly help you with all your wikipedia editing enquires. -- CS Miller (talk) 14:03, 27 July 2011 (UTC)

Looking at your talk page, which is for other editors to discuss your edits, etc, an article you created has been deleted recently. If you are asking about this, then I'd advise you to read the articles linked on your talk page. CS Miller (talk) 14:06, 27 July 2011 (UTC)

Excel formula problem

I need to calculate the standard deviation of a range of values, including the values only if the meet a certain criterion. There doesn't seem to be a STDEVIF function, so how do I do it? Probably somehow using IF, but I'm having trouble figuring it out. ike9898 (talk) 15:11, 27 July 2011 (UTC)

Can you give us some sample data, to make sure we understand what you're asking for, specifically? --Mr.98 (talk) 15:23, 27 July 2011 (UTC)

It will be easiest to make another set using something like "if(A1>=0,A1)". All of the fields that don't meet the criteria will be filed with FALSE and will not be included if you perform stdev on the new set. -- kainaw™ 15:33, 27 July 2011 (UTC)

Figured it out. Answer took the form =STDEV(IF($V7:$V12="G",O7:O12,"")), that is, =STDEV(IF(criterion,range of values to conditionally include in calculation ,"")) ike9898 (talk) 16:52, 27 July 2011 (UTC)

Appropriate usage of SSD term?

Today I found myself using the term "SSD hard drive" when writing an email to co-worker. And I realized how redundant and incorrect that is. Even "SSD drive" is redundant. But "SS Drive" sounds like something Nazis would use. Just plain "SSD" doesn't seem descriptive enough to people outside of tech circles. What commonly accepted usage have you seen in non-technical blogs and articles? --24.249.59.89 (talk) 15:35, 27 July 2011 (UTC)

SSD drive is normal (and could be a reference to Solid State Device drive). I often see references to SSD disks, which I feel is worse. It is very common for acronyms to be used with redundancy: CD disk, ATM machine, etc... -- kainaw™ 15:41, 27 July 2011 (UTC)

Acid3 source code

How do I get the source code of the Acid3 test? 125.235.98.33 (talk) 16:08, 27 July 2011 (UTC)

It's all in one page (there's no includes) in the source of the ACID 3 test itself. You can "view source" in your browser to look at it. -- Finlay McWalter ☻ Talk 16:48, 27 July 2011 (UTC)

Vista's "Run..." doesn't save

Hello, I'm using a computer running Vista. Prior to a week ago, "Run..." (Windows key + R) would save the previous items I typed in. Now, even if I just typed something in a few minutes ago, when I go back there's nothing in the list. Can anyone help? -- 143.85.199.241 (talk) 17:56, 27 July 2011 (UTC)

July 28

Windows XP moniter problem

I actually have had this problem for a couple of years now, but now it seems to have reached a stage where it can't fix itself. My moniter screen occasionally puts up a message in a blue box stating "No Signal Analog 2", before shutting down (by which I mean just the moniter, not the computer itself). I usually have to restart the computer to fix this, after which it works fine, until I turn it off, in which when I try to turn it back on it may do this again. Now though, I have restarted my computer 10 times already, and the moniter is still not displaying anything other than the message before promptly shutting down. Is there a problem with the wires or is the processor somehow damaged? Is it possible to fix this problem without the need to replace my moniter? 72.235.221.120 (talk) 00:13, 28 July 2011 (UTC)