Wikipedia:Reference desk/Archives/Computing/2015 April 6

= April 6 =

Javascript any # between 3 and 21
My code for some reason is not working like expected. I have a prompt that asks for the user to pick a number between 3 and 21. Then the number the user inputs in the prompt gets assigned to a variable. if the number is below 3 they get an error message if the number is over 21 they get an error message that is what is intended to happen. Then if the number is some number between 3 and 21 that number gets assigned to the variable and is posted. The code I have so far:


 * (If you don't mind, I've added some formatting code to make the program easier to read.)
 * If you mean that the user should input a number between 3 and 21 including 3 and 21 (3, 4, 5, ..., 20, or 21), then you should change the comparisons to >= 3 and <= 21.  Anon 126   (notify me of responses! / talk / contribs) 00:26, 6 April 2015 (UTC)

Apologies the numbers were typed in wrong the problem still remains though.


 * What exactly is the problem? This may not be relevant, but I believe you should use the parseInt function to convert the input string into an integer.  Anon 126   (notify me of responses! / talk / contribs) 02:47, 6 April 2015 (UTC)


 * Every number is either >= 3 or <= 21, so you will never get to the error case. -- BenRG (talk) 02:57, 6 April 2015 (UTC)

If every number is that then how do I do this correctly in javascript? I just need to have the user pick a number between 3 and 21 its not that hard why cant I figure this out at all. — Preceding unsigned comment added by 204.42.31.250 (talk) 04:11, 6 April 2015 (UTC)
 * You need to combine the checks into a single if statement with an "and." Right now you're effectively using an "or."  Mr.Z-man 05:35, 6 April 2015 (UTC)


 * Your code first checks whether the number is >= 3. If the number is (for example) 2, it will fail that test and go to the next test. It will pass the second test since 2 <= 21. Every number will pass one of the two tests. Javascript is doing what you told it to do, but what you told it to do doesn't make sense. -- BenRG (talk) 07:30, 6 April 2015 (UTC)

Thank you the problem is fixed before when I tried to fix the problem I used something else instead of the && thats why when I attempted to fix it before posting on here it wouldnt work. — Preceding unsigned comment added by 204.42.31.250 (talk) 14:00, 6 April 2015 (UTC)

keyboard
Would a 5-pin DIN keyboard connected to a 5-pin DIN to PS/2 adapter then connected to a PS/2 to USB adapter work on a modern Windows 8 computer? — Preceding unsigned comment added by 104.223.3.223 (talk) 00:06, 6 April 2015 (UTC)


 * I doubt it. I believe it's more than just the plug that changed, the format of the signal changed too, and a format that old isn't likely to be supported any more. StuRat (talk) 06:28, 6 April 2015 (UTC)

Trying to setup PPTP VPN Router
Hi,

I'm trying to setup a PPTP VPN server on one of my routers at home. I tried making it work on my second router (Linksys E1200v2) which runs on DD-WRT, but even after many hours of Googling, I couldn't get it to work. I also tried making it work on an older router (Cisco WRT120N), but had no luck either. -- the main objective is to make the Roku 3 streaming machines run on a VPN network. Ideally, I'd like it to work on the third router, essentially making the Roku users (not very "computer literate"( the ability to switch between Router 2 (Netflix Canada) and Router 3 (Netflix U.S.) -- if this couldn't work, then Router 2 would be better than nothing.

I tried following tutorials everywhere; making the router run in DMZ, shutting down the hardware firewall, etc., to no avail. I tried contacting PureVPN support, but they didn't really seem to know what's up, besides unchecking/checking things and then praying that it would work. Here's a graphic of my network (the USB ethernet dongle can easily change device - I use for security reasons, i.e. no wireless admin access): https://i.imgur.com/xaiO1iY.png

I do know it's a lot of cable salad.

Router settings album: https://imgur.com/a/39ynd would gladly take more if needed. Matt714 (talk) 00:22, 6 April 2015 (UTC)

Need help locating ERAS code base on github
I'm trying to follow this tutorial, but am having problem locating this "kinect-install.sh" file that's "provided inside body_tracker/tracker at ERAS code base on github". I tried googling with various search terms but still can't find this ERAS code base that's supposed to be on github. Usually for big project it's just https://github.com/ERAS/body_tracker or something to that effect. WinterWall (talk) 03:25, 6 April 2015 (UTC)

Videos
Can any kind soul please advise me why four videos taken on my car cam, and transferred to my AppleMac desk top application 'iPhoto', do not all transfer to my AppleTV, only one has done so. Other videos do so as, of course, do all my photos.85.211.129.200 (talk) 03:32, 6 April 2015 (UTC)
 * There could be several reasons, I suppose. The most basic of which is whether the ATV has enough space on it for all the videos.  Dismas |(talk) 03:34, 6 April 2015 (UTC)

For this issue it is most likely because you're appl tv may not have enough space on it. Try clearing some space with old videos and try the transfer again. If this option does not work you can either try to transfer in a different program or to simply contact your local apple store about the issue. source: http://apple.stackexchange.com/questions/47058/cant-stream-itunes-purchased-movie-from-mac-to-apple-tv https://support.apple.com/en-us/HT201784 http://store.apple.com/us/questions/appletv?po=7&st=appletv_streaming_with_icloud_airplay — Preceding unsigned comment added by Thegangoo (talk • contribs) 20:25, 6 April 2015 (UTC)

Google Translate
Is there a way to have Google Translate show me the Latin character spelling for a, for example, Japanese word? All it keeps giving me is kanji (or maybe it's katakana, I don't know) and I'd rather have the Latin characters. Thanks, Dismas |(talk) 04:08, 6 April 2015 (UTC)
 * Google Translate does it automatically. For example, see the Romaji "Nihon" in light grey on the right side here. (Your Google interface might be different though, Google's interface changes based on geographical locations.) WinterWall (talk) 06:07, 6 April 2015 (UTC)
 * Seems like the Ä button turns the phonetic spelling on. On my end it's enable by default. Maybe it's off by default on your end, so that might explain the difference. WinterWall (talk) 06:11, 6 April 2015 (UTC)
 * Ah! So that's what that does! I misunderstood what it meant.  I thought it would provide some sort of pronunciation guide which wasn't working for me.  I was also expecting the Romaji to replace the kanji inside the results box but instead it displays below the results box.  Thanks, Dismas |(talk) 07:00, 6 April 2015 (UTC)

Setting background color of frame in Java
I'm trying to work out a small programming assignment that will change the background of a JFrame to a specific color. I've added a comment near the end of the code where I think the color should go but nothing I do seems to work. Am I on the right track? I thought I'd be able to pull the value straight from the JComboBox but that doesn't seem to work either.

Thanks, Dismas |(talk) 07:08, 6 April 2015 (UTC)


 * What you need to set a Swing component's background colour is a   object (which, incidentally, is a good reason to rename your program to   or something).  There isn't a general mechanism in Swing to map a String into a Color (don't be misled by the mostly useless  ). Here are some options you can use:
 * Use a fixed menu of colours (so not a Combobox, which allows free input) and keep an array that remembers that the first option picked is Color.red, the second Color.white, etc.
 * Build a Hashmap which maps a lot of color names to RGB values (on Linux etc. you use the X11 color names: >700 mappings in   - or you could use a table derived from the standard HTML colour names).
 * Get the users to input R, G, and B values instead of a string.
 * You could even use reflection to obtain the constant values and their strings out of java.awt.Color (but this is bonkers).
 * Use a JColorChooser instead.
 * -- Finlay McWalterᚠTalk 08:09, 6 April 2015 (UTC)


 * The assignment was to use a JComboBox to change the background color. And I've made the combobox uneditable.  Dismas |(talk) 08:25, 6 April 2015 (UTC)


 * You'll probably have a happier time if you use  rather than  . You can use that as an index into the string array of names you provided (giving you the colour name) and into a parallel array of java.awt.Color objects. -- Finlay McWalterᚠTalk 12:35, 6 April 2015 (UTC)

Webcam question
Why are ethernet webcams so much more expensive than usb webcams? 117.173.22.50 (talk) 11:37, 6 April 2015 (UTC)


 * Prevailing economic theory implies that the supply and demand curves for ethernet cameras equilibrate at a higher price and lower volume than USB competitors. Fewer companies make ethernet cameras; they are arguably more difficult to engineer, more difficult to operate, and less useful to general consumers.  However, some people want or need their features, so they must pay a premium for the product.  Nimur (talk) 12:01, 6 April 2015 (UTC)


 * The Webcam requird to work a a host or full computer itself, running several software. Maybe a smartphone based device will make the prices drop. -- Hans Haase (有问题吗) 13:59, 6 April 2015 (UTC)

Advantages of external ssds
Generally when buying a new laptop, is it better to buy a small internal SSD like 128gb and buy a separate external SSD for extra storage or is it better just to buy internal SSD? What are the advantages of either. 90.198.252.17 (talk) 12:09, 6 April 2015 (UTC)


 * Probably better to buy a normal hard drive for the external as you get far more gig for your buck and it being a bit slower than an SSD makes no difference when you are limited by the USB cable speed anyway. SSDs are only useful as internal drives for booting and caching. — Preceding unsigned comment added by 120.206.189.82 (talk) 12:16, 6 April 2015 (UTC)
 * thanks. That's good advice. But do you think it's better to get a large internal ssd to start with or is it better to get a small internal one and external one to make up for the small internal capacity? 46.233.112.165 (talk) 12:33, 6 April 2015 (UTC)
 * Well, You did not focus on dropping the running device from a desk. -- Hans Haase (有问题吗) 13:56, 6 April 2015 (UTC)


 * The question you should ask yourself is really how fast can the data be transferred through those various methods and does that make it worth it to even have an SSD as external storage. USB 2.0, according to an article on pcworld.com (http://www.pcworld.com/article/2360306/usb-3-0-speed-real-and-imagined.html) can handle up to 60 MB/s while in the same article It is stated that USB 3.0 can handle a whopping 640 MB/s. These are the two most common interfaces for external storage. On the other hand, internally, we find that SATA III can handle up to 600 MB/s (http://kb.sandisk.com/app/answers/detail/a_id/8142/~/difference-between-sata-i,-sata-ii-and-sata-iii) . Upon searching the best reviewed SSD of 2015, I found a page on CNET (http://www.cnet.com/products/samsung-ssd-850-evo/) that recommended the Samsung Evo 850 as their SSD of choice, which has a read speed of 540 MB/s and write speed of 520 MB/s. Neither of these speeds take advantage of either USB 3.0 or SATA III. For these reasons, if you are mostly using primarily USB 2.0 as your external storage method, an external SSD would but pointless, so just get a good-sized internal to really speed up your machine. On the other hand, if you are making use of USB 3.0 for your external storage while having SATA III internally, having all that space conveniently inside your machine might be more efficient, but you won’t lose any speed necessarily by having it outside of your machine either. — Preceding unsigned comment added by Dcarrier93 (talk • contribs) 18:11, 7 April 2015 (UTC)
 * Note that the maximum practical throughput from USB 2 mass storage devices seems to be about 35MB/s. Also the main reason people choose an SSD over a HD is not because of the transfer speed. Sure it's an advantage, but it's rarely the main reason (and if it is, most of the time it indicates the person doesn't really what they're doing). The main advantage is much better random access. For a portable drive, SSDs will also tend to be much less vunerable to shock or vibration. I'm not saying it makes much sense to choose a SSD USB2.0 drive, it rarely would, and the low transfer speed is a significant reason but you definitely shouldn't think as transfer speed as the end all. You need to consider what you're going to be using the drive for and what you want from it. Nil Einne (talk) 02:59, 8 April 2015 (UTC)

Discussion search
Discussion seach was the best thing google had going IMO. But now that its gone, is there any decent alternatives that do the same thing that anyone can recommend? — Preceding unsigned comment added by 86.24.128.230 (talk) 13:26, 6 April 2015 (UTC)
 * Build your own search engine! You can use Apache Lucene to do the heavy lifting, and simply provide it with an archived corpus of the text you wish to index.
 * In itself, text search is a very simple problem - one of the oldest problems that was solved by the very first computer scientists. The complexity of modern search technology really comes from optimization of common index terms, and the cultivation and curation of a high quality text corpus.  If you already know what data you wish to search (e.g. a finite number of archived discussions), the problem is, as the mathematicians say, reducible to an already solved one.
 * Nimur (talk) 15:39, 6 April 2015 (UTC)

Radeon HD 7350 4K Support
Does Radeon HD 7350 support 4096 x 2160 resolution?WinterWall (talk) 14:39, 6 April 2015 (UTC)


 * This page, found after about a minute of searching, indicates it won't. It looks like the 7350 is a fairly low end card in the Radeon HD 7000 Series. WegianWarrior (talk) 14:49, 6 April 2015 (UTC)

It does not. The maximum resolution supported is 2560X1600. This information was found using these three pages: http://www.gpuzoo.com/GPU-AMD/Radeon_HD_7350_GDDR3_OEM.html http://www.techpowerup.com/gpudb/632/radeon-hd-7350-oem.html http://www.futuremark.com/hardware/gpu/AMD+Radeon+HD+7350/games

I would suggest using Google to help in your search for a graphics card. Try tigerdirect or newegg if you are looking for good cards to buy. Do your research and you will get a good card. Good luck. — Preceding unsigned comment added by Nickelghandi (talk • contribs) 22:24, 7 April 2015 (UTC)

Unfortunately the Radeon HD 7350 does not support 4K resolution. These sites can show you the specifications of the graphics card. http://www.cnet.com/products/visiontek-radeon-hd-7350-sff-graphics-card-radeon-hd-7350-1-gb/specs/ http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=7963155 http://www.gpuzoo.com/GPU-AMD/Radeon_HD_7350_GDDR3_OEM.html Semurp18 (talk) 02:07, 9 April 2015 (UTC) — Preceding unsigned comment added by Semurp18 (talk • contribs) 03:48, 8 April 2015 (UTC)

Downloaded slate.com pages, got a lot of strange svg files
I was checking why the pages that I downloaded from slate.com were so heavy. In the directory of files, there were a lot of files with the name pattern 8-4-4-4-12-1 alphanumeric characters and the extension svg. For example, 0c265de5-3d1f-17bb-0892-a3409dde2fbd-4.svg is one of them. They are rather heavy 300 kB each and there are maybe dozen of these in each slate page. The amazing thing is that they are empty when opened when a graphical program, and deleting them does not change the appearance of the saved page.

What are they there for? 87.216.165.193 (talk) 16:16, 6 April 2015 (UTC)


 * The 8-4-4-4-12 pattern is characteristic of a GUID, but that doesn't help answer the question.
 * When I visited slate.com just now with Windows Chrome, it didn't download any SVG files, but it did download 12 WOFF files with the same name pattern and sizes from 27K–60K. It may be falling back to SVG fonts for your browser. SVG is much less space efficient than WOFF. Those files should stick in your cache and shouldn't be redownloaded every time you load a Slate page. -- BenRG (talk) 18:01, 6 April 2015 (UTC)

Screen: Reflect light instead of backlight
Couldn't a computer screen just reflect all light, like the kindle, but in color? The computer could manage each pixel to reflect different colors of light. However, it seems that there is no technology like this on the market. — Preceding unsigned comment added by 87.216.165.193 (talk) 17:13, 6 April 2015 (UTC)


 * Transflective liquid-crystal display -- Finlay McWalterᚠTalk 17:18, 6 April 2015 (UTC)


 * This article discusses why transflective displays haven't caught on. -- Finlay McWalterᚠTalk 17:26, 6 April 2015 (UTC)


 * Color e-ink technology exists and is in use. It is simply not popular. 209.149.113.89 (talk) 18:15, 6 April 2015 (UTC)


 * Seems like the problem is that the current version is too expensive and looks washed out using the backlight. The 2nd problem could possibly be handled by having both a reflective display and a backlight display.  This would be ideal on applications where space and weight isn't critical, like an ATM machine.  As for the expense, hopefully technology will bring that down. StuRat (talk) 19:14, 6 April 2015 (UTC)


 * Some portable GPS devices made for hiking use transflective technology to show color maps and images while conserving battery power. Owning one, I can tell you the display is washed out, but quite readable in daylight. --Mark viking (talk) 20:10, 6 April 2015 (UTC)

Data weight
If you weighed a new, blank 1TB hard drive and then wrote 1TB of data to it, would it weigh more afterwards? Microscopically speaking. 200.24.106.194 (talk) 19:55, 6 April 2015 (UTC)
 * No. Ruslik_ Zero 20:22, 6 April 2015 (UTC)
 * Actually if by "microscopically speaking" the OP meant "difference so small even the most accurate scale won't detect it and would be well within the margin of error of nearly everything" then I would say the answer is may be. At the very least, if you're talking about just after writing the data, it's likely the hard disk will be hotter. If you wait for the hard disk to reach the same temperature as before, then I think it will be the same. Nil Einne (talk) 02:06, 7 April 2015 (UTC)


 * Hard drives always have data on them. When it ships from the factory it probably contains mostly zeroes, but that's still data. Zeroes don't have less mass than ones.
 * Since magnetic fields have mass, it is possible that some data patterns on magnetic media have intrinsically larger masses than others. If the data were just recorded by assigning 0 and 1 to opposite spin directions, then a platter containing mostly zeroes (or mostly ones) would probably have a slightly larger mass than one containing random bits, so the mass would probably decrease when you wrote your data. In reality, the relationship between the user data and the magnetic domains is much more complicated. (Floppy drives and old hard drives used MFM, but modern hard drives use proprietary and probably secret schemes.) -- BenRG (talk) 07:23, 7 April 2015 (UTC)


 * Early digital magnetic recording systems used Manchester coding, which has no DC bias (meaning there's no net current over a nontrivial sequence); I would expect a Manchester coded magnetic recording scheme would similarly result in no net change of the magnetic field over a non-small region - regardless of what is stored. Later disks use Viterbi coding which I think is similarly balanced and so again shouldn't have net effect. It may be that those proprietary storage schemes use something like trellis coding or maybe turbo coding, and I've no clue as to whether they have a net bias. -- Finlay McWalterᚠTalk 11:30, 7 April 2015 (UTC)


 * Dilbert, 1995. AndrewWTaylor (talk) 13:35, 7 April 2015 (UTC)