Wikipedia:Reference desk/Archives/Computing/2013 June 16

= June 16 =

Java update question...
I recently decided to disable Java in my browser (IE9.) I did so by going to Tools --> Manage add-ons and then choosing 'disable' on both Java things listed. However, every time I go on my laptop I get a notification that says "jucheck.exe" (or something) would like to run but needs permisson...I choose cancel and then in the bottom-right it says a new version of Java is ready to be installed! This gets annoying because for a few minutes before the message appears and a couple minutes after I cancel it my browser runs really slow. How do I stop this from happening? Thanks! --Yellow1996 (talk) 00:06, 16 June 2013 (UTC)


 * You need to go to add-and-remove-programs and uninstall "Java Runtime Environment". -- Finlay McWalterჷTalk 00:07, 16 June 2013 (UTC)


 * It's not listed! All I've got is Java(TM) 6 Update 6 and Java(TM) 6 update 38?! --Yellow1996 (talk) 00:13, 16 June 2013 (UTC)
 * Should I just uninstall those? --Yellow1996 (talk) 00:22, 16 June 2013 (UTC)

I just went ahead and uninstalled those two listed. Java isn't listed anywhere on my computer (that I can see...) anymore, so hopefully I did things right. We'll see if I get the notification next time. --Yellow1996 (talk) 17:14, 16 June 2013 (UTC)

No notification! Guess it worked. Thanks for pointing me in the right direction, Finlay! :) --Yellow1996 (talk) 01:30, 17 June 2013 (UTC)

Can you run 64 bit Windows on a 32 bit CPU?
Topic says it all. ScienceApe (talk) 02:13, 16 June 2013 (UTC)


 * No. Bubba73 You talkin' to me? 02:16, 16 June 2013 (UTC)


 * Not without virtualization, which you wouldn’t want to go through with, no. ¦ Reisio (talk) 04:04, 16 June 2013 (UTC)


 * Don't think you could do with virtualization as it requires the host and guest to support the same instruction set. You could do it by Emulating a 64-bit computer on a 32-bit one, but the performance penalty would be horrible.    d avid p rior  t/c 20:58, 17 June 2013 (UTC)
 * Most emulators these days use dynamic recompilation, so I don't expect the performance penalty would be too bad. --Carnildo (talk) 02:21, 18 June 2013 (UTC)

cable modem dropping/rebooting
For the last few weeks my cable modem has been dropping the internet, often twice a day or more. Sometimes it comes back by itself in about 2 minutes. When it doesn't, unplugging the power and plugging it back in usually seems to not work whereas unplugging the power AND unscrewing the cable, then reconnecting both seems to usually work. When I call the cable company about connection problems, that is always what they tell me to do first (un-connect and reconnect both). Unplugging the power is easy, but I'm getting tired of doing the coax cable. I'm thinking of getting a coax cable switch to disconnect and reconnect the cable easier. Is there something better to do? Bubba73 You talkin' to me? 02:15, 16 June 2013 (UTC)


 * How old is your modem? This happened to me once and my solution was getting a new one... --Yellow1996 (talk) 17:16, 16 June 2013 (UTC)


 * A few years old, probably 3 years, maybe 4. Bubba73 You talkin' to me? 17:36, 16 June 2013 (UTC)


 * That's about how old mine was. If you don't feel like paying the extra money and don't mind getting a coax cable switch and doing it that way, then stick with that strategy. If not, you could just get a replacement and see if the problem still persists. --Yellow1996 (talk) 17:44, 16 June 2013 (UTC)


 * It turns out that I have an older cable modem (9-10 years) that was working when I quit using it. I could try it.  Bubba73 You talkin' to me? 18:26, 16 June 2013 (UTC)


 * The older modem may not support the required version of DOCSIS. Check with your cable company to see if, for example, they require 2.0 or above.  RudolfRed (talk) 19:55, 16 June 2013 (UTC)

Fluctuating power levels is usually the culprit 77.101.52.130 (talk) 21:35, 16 June 2013 (UTC)


 * That says that the S/N ratio should be > 30 and the downstream power level should be between -8 and +8. I looked at the modem stats and the S/N is 36-37 and the power level is -6.0 to -6.3,  I'll look at it from time to time.  Bubba73 You talkin' to me? 22:26, 16 June 2013 (UTC)


 * I looked at the modem log and it is getting a lot of T3 timeouts. I'm not sure, would that be on their end or mine?  Bubba73 You talkin' to me? 22:30, 16 June 2013 (UTC)


 * T3 timeouts are when your modem fails to communicate with the ISPs equipment and after 3 seconds of trying it reboots itself. There are many things that could be causing it, most of them on the ISPs end like damaged underground cables, noise leaking onto the network from somewhere, faulty lasers at the optical node, etc. However, it could also be that your modem is failing. Typically the first step in an situation like this is for the ISP to send you a replacement modem to rule that out. If after getting a new modem the problem persists, then it is clearly on their end and they will have to chase down the noise or repull cables to fix it 77.101.52.130 (talk) 10:49, 17 June 2013 (UTC)


 * I bought my own modem years ago to not have to rent one from them. Bubba73 You talkin' to me? 14:51, 17 June 2013 (UTC)


 * It may be possible that they would send you a "tester" unit just to rule out any issues on their end. Alternatively, you could try and track down a cheap one to use as a tester. --Yellow1996 (talk) 19:29, 17 June 2013 (UTC)


 * Yes. Maybe I should start renting one from them and if the problems continue, I can say "fix it".  If the problems go away, it is the modem and I can replace it.  Bubba73 You talkin' to me? 23:46, 17 June 2013 (UTC)

It was dropping several times per day. Now I haven't seen it drop for a few days. Bubba73 You talkin' to me? 18:41, 21 June 2013 (UTC)

Internet imux in Win 7
What would be the easiest way to inverse-multiplex a (generally higher-bandwidth and lower-latency) wired cable connection with wireless DSL (kept mainly as a fallback, and to accommodate other devices) on a Windows 7 Ultimate high-end desktop PC (Core i7 2600K 4×≥3.4GHz, ≥16GiB ≥2133MHz DDR3, GTX ≥480), downstream of both modems? (≥ signs indicate specs that I softly-can afford to upgrade or overclock -- although I'd be upgrading at the margin, and probably paying at least 150% of the international market rate since I'm a full-time grad student living in Canada.) Neon  Merlin  07:31, 16 June 2013 (UTC)

What types of computer science classes are best for landing a high-paying job?
Hello, I am wondering what are the best types of college-level (can be undergraduate or graduate) classes you can take that will teach you useful technical skills for a high-paying job. You can answer this question two ways 1) classes that you took that would look good on a resume/CV and impress the employer or 2) classes that you took that will teach you useful technical knowledge for when you are actually on the job.

I am NOT trying to start a debate about the merits/flaws of Computer Science departments/programs in general, or whether academic knowledge is less useful than practical knowledge gained outside the classroom. Nor am I soliciting complaints about the current state of the job market for computer professionals. Those topics are interesting but they are not what I need help with. Given the realities of how computer science classes are, what are the most useful (or least useless) classes?--24.228.93.254 (talk) 11:11, 16 June 2013 (UTC)


 * Hard to address, because the potential to be paid more is higher if you pursue some other field, or start your own business. Within computer science you would actually be paid more by specializing in something not a lot of people are able to deal with, thus making your skillset rarer and more valuable; but it could be argued this would net you less money in the long run as well (because the competition will be greater). If you merely want a high likelihood of being able to get a decent job, you need only familiarize yourself with whatever programming languages and frameworks establishments of the sort you’d be interested in working for use. ¦ Reisio (talk) 13:01, 16 June 2013 (UTC)


 * This question has recently been addressed at The Register, by someone who (apparently) knows. --Demiurge1000 (talk) 13:38, 16 June 2013 (UTC)
 * I was about to suggest "mathematics, and then more mathematics, and then even more mathematics..." - but it looks like Demiurge1000's reference already says so! (The humorous piece is spot-on about a few other things too - be sure you're good with computers, if you pretend to a computer science degree!  For all that it's worth, learn to program in the C language - whatever other language(s) you might also learn - and learn how computers work).  Depending on where you go to school, your college or university might administer math coursework through a different department or degree-track than the "Computer Science" program.  However, a properly trained computer scientist should be almost a full-blown mathematician.  Take math courses, even when they don't appear very applied, and think about how you might build a machine that can perform such mathematics.  Towards the top of the scale, math- and computer-science classes are often indistinguishable.  I highly recommend the subject(s) commonly lumped together as "analysis": numerical analysis, algorithm analysis, and so on.  A good computer science, math, or engineering school should offer a few dozen electives relating to analysis, in pure or applied form.  Nimur (talk) 20:49, 16 June 2013 (UTC)
 * As part of my MLS program, I was required to spend a couple of weeks in a technical class learning the basics of working with UNIX directories and things such as PuTTY. The UNIX professional who taught it observed that there are comparatively few UNIX professionals around anymore and suggested that anyone becoming familiar with it would have a good chance of finding good employment in working with un-replaceable legacy systems.  Bear in mind that this was three years ago, so things may well have changed since that time.  Nyttend (talk) 20:20, 16 June 2013 (UTC)
 * “Unix” is still a must for this type of work, but probably not as much the peculiarities of proprietary and legacy versions of Unix. ¦ Reisio (talk) 01:19, 17 June 2013 (UTC)

Thanks for the helpful answers and the interesting article. I'm just starting a computer science program in college and I am certainly willing to take a lot of advanced math classes (a lot of the higher level CS courses have math prerequisites). I know a lot of people who are good with computers but couldn't handle the math aspects of CS and thus dropped out of the program. As for me, I am good with math/logic but I'm not a math genius by any means; I've always gotten an A in every math class I've taken, BUT I've never taken anything beyond basic calculus before... should I be scared/concerned?--24.228.93.254 (talk) 11:33, 17 June 2013 (UTC)
 * Scared not, but prepared to put a lot of work into math. I graduated high school with excellent grades and a specialisation in math and physics. It took me about a semester at university to notice that the math there was a lot different, and required much more serious study than high school material (which to me always felt as if I absorbed it automatically by osmosis). Get the textbook (or a textbook), and do all the exercises requested, plus a few more. For me, Schaum's Outlines on linear algebra came to the rescue and bridged the gap nicely. --Stephan Schulz (talk) 14:08, 17 June 2013 (UTC)

New Forum
I want to create a new internet forum, I have a domain name and have paid for hosting of it, but I'm not sure how to get the forum itself onto the internet. I quite like this vanilla (forum) thing, but once I have it, how do I put it onto the webpage I want and edit it the way I'd like, I know very little about this aspect of websites, and the available instructions I've found just confuse me. Can someone give more basic instructions, or point me towards a better, more in-depth guide? If it helps, I'm running Linux Mint on my main computer. 213.104.128.16 (talk) 20:15, 16 June 2013 (UTC)
 * The answer depends on what web-hosting service you are using. Each hosting service gives you a mechanism for uploading things, but the mechanisms vary, and many of them impose restrictions on what software you can use.  We might be able to give a more specific answer if you tell us your web-hosting service. Looie496 (talk) 23:40, 16 June 2013 (UTC)


 * using godaddy.com for hosting. I'm sure they have some way of uploading stuff, but I couldn't work it out before, even with help. 213.104.128.16 (talk) 00:06, 17 June 2013 (UTC)


 * I'm not familiar with godaddy, but I assume you could just contact them and get them to explain the method? --Yellow1996 (talk) 01:33, 17 June 2013 (UTC)


 * Start by reading http://support.godaddy.com/help/article/6815/building-your-first-web-page, if you haven't already. Probably the easiest way to add a forum is to use Godaddy's Website Builder add-on -- you can find instructions at http://support.godaddy.com/help/article/7723/adding-a-forum-in-website-builder.  There are other ways to do it, but they require either additional software such as Microsoft's Expression Web or a lot more sophistication than you have right now. Looie496 (talk) 15:32, 17 June 2013 (UTC)


 * that building a webpage help isn't much use, since it covers buying a domain name and writing basic text, rather than uploading existing pages to the site, but I am looking around at other help topics, in case they're any more useful. Their website builder is rather expensive, considering I can get the same thing for free. 213.104.128.16 (talk) 15:38, 18 June 2013 (UTC)

Well, I figured it out, it was pretty simple in the end, just had to look up my site's IP, username and password on the account, set that in the FTP program, then just drag and drop the entire downloaded folder and it's done :) 213.104.128.16 (talk) 16:15, 18 June 2013 (UTC)


 * Awesome! Glad to hear that worked out for you. I hope your forum is a success! :) --Yellow1996 (talk) 16:22, 18 June 2013 (UTC)

Extracting image from PDF
The lower image on page 4 of this document is credited to a United States Department of Energy agency, and since it depicts a site that I'm trying to illustrate, I'd love to upload it with a PD-USGov license tag. How do I get the image? I know how to take a screenshot, but I don't otherwise how to get images out of unsecured PDFs. Nyttend (talk) 20:23, 16 June 2013 (UTC)


 * The pdfimages program in Linux makes this easy. --Mark viking (talk) 20:34, 16 June 2013 (UTC)
 * You can get Windows binaries of pdfimages from the xpdf download page (in xpdfbin-win-3.03.zip). Later on the page are links to third-party binaries for other OSes including OS X. -- BenRG 02:56, 17 June 2013 (UTC)


 * ; I used evince. -- Finlay McWalterჷTalk 21:20, 16 June 2013 (UTC)
 * Thanks! I read the evince article and everything that seemed relevant on their website, but nothing appeared to mention the kinds of image files with which it can work — for example, I never noticed anything about jpg.  Does it know how to work with svg and png?  Nyttend (talk) 01:04, 17 June 2013 (UTC)


 * Finlay's extracted image is missing the bottom part (which is stored in the PDF as a separate image for some reason), and it's been converted to JPEG (the original is a gzipped bitmap). You can probably save the two images as PNGs from evince and stitch them together without any loss. pdfimages is preferable when you're extracting images that are actually JPEG-encoded in the PDF file – it can extract those losslessly to .jpg files, which most other tools can't (probably including evince). pstoedit, which I've never used, can allegedly extract vector images to .svg files. -- BenRG 02:56, 17 June 2013 (UTC)