Wikipedia:Reference desk/Computing

The Wikipedia Reference Desk covering the topic of computing.
Computing #eee #f5f5f5 #eee #aaa #aaa #aaa #00f #36b #000 #00f computing Wikipedia:Reference desk/Computing Computing WP:RD/C

Welcome to the computing reference desk. Want a faster answer? Main page: Help searching Wikipedia How can I get my question answered? Provide a short header that gives the general topic of the question. Type ~~~~ (four tildes) at the end – this signs and dates your contribution so we know who wrote what and when. Post your question to only one desk. Don't post personal contact information – it will be removed. We'll answer here within a few days. Note: We don't answer (and may remove) questions that require medical diagnosis or legal advice. We don't answer requests for opinions, predictions or debate. We don't do your homework for you, though we’ll help you past the stuck point. How do I answer a question? Main page: Wikipedia:Reference desk/Guidelines The best answers address the question directly, and back up facts with wikilinks and links to sources. Do not edit others' comments and do not give any medical or legal advice.

skip to bottom Choose a topic: Computing desk Entertainment desk Humanities desk Language desk Mathematics desk Science desk Miscellaneous desk Archives   See also: Help desk Village pump Help manual

November 15

Blocking web mail traffic to a specific version of Outlook?

Is there anyway a network administrator can distinguish between the traffic going between Outlook 2010 vs Outlook 2013 to the mail server? That is to say, is there anyway the admin can prevent users from using Outlook 2013 to retrieve emails from the company servers and force users to use Outlook 2010? Acceptable (talk) 17:20, 15 November 2014 (UTC)

The standard mail protocols, such as IMAP, do not require the client software to report anything. You can see the IMAP exchange on Internet Message Access Protocol. It is plain text. Now, if you limit users to an off Outlook protocol that only works with Outlook and is inherently broken for everyone who isn't using Outlook, then you can do anything you like. This is an ongoing security issue. The security management wants to make email secure by ensuring that nobody can send or receive email. The business management wants email to simply work without any sort of security issues at all. Smart businesses fall in the middle somewhere. 209.149.113.112 (talk) 18:13, 17 November 2014 (UTC)

Frequent Computer Sleep

I bought a laptop (Lenovo Yoga 2) a little while back for use in the classroom. I haven’t had an occasion to use a personal laptop for years, so I have been predominately using an iPhone (usually just small tasks like checking emails, social media, etc.). I had become very accustomed to being able to turn the screen off in the short periods of time where I wasn’t using my phone. In other words, if I wasn’t using my phone for 5 minutes or so, there is no reason to shut it off, no reason to have the screen on, so I would tap the top button to shut the screen off (lock the phone). Now that I’m back to using a laptop for full days, I’m looking to maximize my battery life.

In short, I’m wondering if it’s bad to routinely put my laptop to “sleep” while I’m not using it in order to save battery life. Note that I use my laptop in tablet mode as well, so it’s not just as simple as closing the screen. Is it bad for my computer to put it to “sleep” 5 or 6 times each hour?72.10.109.131 (talk) 18:11, 15 November 2014 (UTC)

I set my laptop to go to sleep if I haven't pressed a key for several minutes. I don't know of any detrimental effects. If you are leaving the machine unattended in the classroom, you might also want to set a password on reawakening (depending on how mischievous your students are). Dbfirs 21:07, 15 November 2014 (UTC)

You can set your laptop to automatically turn off the backlight of the display, but otherwise remain on, after a short period of time. The minimum is probably 1 or 5 minutes. There should be Fn-Key sequence to do this manually; it is probably Fn-F9 for Lenovo Yoga 2 Pros. CS Miller (talk) 13:49, 17 November 2014 (UTC)

(OP here) that's exactly what I was looking for, thanks! I realize now that my initial attempts to learn how to turn of the display backlight (via google) were hidden by the many ways to turn of the keyboard backlight (which I don't even have). Thanks!24.181.250.51 (talk) 00:10, 19 November 2014 (UTC)

Turning off the display will certainly save some battery life, but if you want your battery to last all day, you may need to look at the sleep and hybernate options too. Dbfirs 12:53, 19 November 2014 (UTC)

Removing & Inserting

Once you 'Safely Remove Hardware and Eject Media', how do you reactivate it without unplugging it to re-plug it to function?

Can someone help me to with the steps please, what to do... Regards.

(Russell.mo (talk) 18:35, 15 November 2014 (UTC))

Microsoft says just unplug and replug. Perhaps someone knows a way to reactivate the device driver when unplugging is inconvenient? Dbfirs 21:00, 15 November 2014 (UTC)

I have had to do this when remoted in. You can usually open device manager and scan for new hardware. On occasion I have had to reboot. BTW, you can also right click on the device and eject to safely remove it. --  Gadget850 ^talk 01:32, 16 November 2014 (UTC)

Device Manager doesn't re-find the hardware when it scans in either Vista or Windows 7 (I haven't tried in more recent versions of Windows). I also tried disabling the USB driver, but there's no point because re-enabling requires a reboot. There ought to be some command to fool the driver into thinking that the device has been disconnected, but I don't know enough about the inner workings of Windows drivers to find it. Dbfirs 12:47, 16 November 2014 (UTC)

Unable to find 'scan for new hardware' option, though found 'scan for hardware changes' option - doesn't work... I constantly unplug/remove the USB wire after disconnecting it from the taskbar. I thought there would be a way of reconnecting it without unplugging it. Note: Disconnecting it from the taskbar is safer then disconnecting it from, by right clicking it from the removable device icon. -- (Russell.mo (talk) 13:24, 16 November 2014 (UTC))

Asmrulz (talk) 14:55, 16 November 2014 (UTC)

I'm fairly sure the claim is incorrect. They both do the same thing so the idea one is safer is nonsense, unless you count accidentally disconnecting the wrong thing, forgetting to disconnect, or not noticing it failed to disconnect, but I actually think these generally lean in favour of disconnecting it by right clicking on the device. OTOH, some devices (such as a GPT external disk) won't give an eject option, so there are some non safety related reasons why you might want to use the icon in the notification area. Nil Einne (talk) 05:18, 17 November 2014 (UTC)

BTW, a simple search finds these links [1] [2] [3] which suggests you may be able disable and renable the device to convince Windows to reinitalise the drivers, although it may not work on Windows 7 (whic may mean Vista too), only XP and Windows 8.1 (I imagine 8 too) and you may need to do it twice on Windows 8.1. Windows does ask you to restart, but doesn't seem to require it (i.e. just tell it no and you may be ok). You could try this with the disable USB option controller too and see if it works. Nil Einne (talk) 05:29, 17 November 2014 (UTC)

I think the reason for saying the taskbar icon is safer is probably that it forces the user to maually check and close what is still running, whereas the eject option on rightclick forces closure regardless. I agree that the safely remove option seems to call the same routine by both routes. Despite Nimur's Nil Einne's excellent suggestions, I've not found a way to achieve reconnection without downloading Devcon and using command line. Dbfirs 09:16, 17 November 2014 (UTC)

(Dbfirs, I don't actually recall making any suggestion in this discussion, excellent or otherwise... are you referring to an earlier discussion or a suggestion from a different user? Nimur (talk) 17:48, 17 November 2014 (UTC))

Oops! Apologies, Nimur. You do make excellent suggestions elsewhere, but it was a case of mistaken identity here. I've corrected my silly mistake. Dbfirs 00:59, 18 November 2014 (UTC)

@Asmrulz: Some time ago, I thought both functioned the same way, even unplugging the USB drive manually was the best option for me without safely removing it. Ever since I started valuing my files and folders, I came to realisation, when I eject the USB drive by right clicking it, the flash drive keeps the flash light on, even after when it say ‘you can safely remove it’. When I safely remove it from the taskbar’s notification area, it seems to turn the flash light off. I hope this helps. – experienced with 8GB USB drive and 1TB RHDD. -- (Russell.mo (talk) 10:18, 17 November 2014 (UTC))

As I mentioned above, right-clicking gives two options: eject which forcibly closes any open files, with the possibility of loss of data, and safely remove which is the same as the task bar option. I have removed USB drives hundreds of times in the past without bothering to eject or safely remove, and I've never had problems because I always closed my files manually first. Nevertheless, I would recommend the safely remove option because it checks for you that no files are still open. Dbfirs 12:53, 17 November 2014 (UTC)

Asmrulz needed citation therefore I stated. Sorry, I should've pinged. There is only one 'Safely Remove Hardware and Eject Media' option btw and one 'eject' option, what you find after right clicking on the RDD icon. The other options are available in the 'Device Manager' window.

Anyways, I tried the link what Einne provided, it functions like the way DFbris (as well as Einne) mentioned. It doesn't reconnect until a reboot... -- (Russell.mo (talk) 13:49, 17 November 2014 (UTC))

Per MS, eject and safely remove have the same function.[4] --  Gadget850 ^talk 14:27, 17 November 2014 (UTC)

I haven't done this in a while, so I checked my notes. Looks like I restarted the USB Mass Storage Device, which is described at 5 Ways to Remount Ejected or Safely Removed USB Device Without Unplug and Reinsert. --  Gadget850 ^talk 15:18, 17 November 2014 (UTC)

Thanks, that confirms that it is impossible to remount a USB drive in Vista and Windows 7 without downloading special software. Despite what Microsoft says in your link, eject is not the same as safely remove. They are separate options on right-click in Vista, and behave slightly differently in Windows 7, though I accept that eject probably calls the safely remove routine after closing files. Dbfirs 00:53, 18 November 2014 (UTC)

No luck with my OS either.

Thank you all. I appreciate. Regards. (Russell.mo (talk) 18:52, 18 November 2014 (UTC))

Speech recognition

Is anyone fully experienced with the ‘speech recognition’ software? I say something and it writes something else. How can I make it affective? -- (Russell.mo (talk) 18:41, 15 November 2014 (UTC))

You can make it more effective by training it to recognise your speech patterns. I haven't used such software for many years, but doesn't it still require several training sessions to accurately reproduce your words? You don't tell us which brand of software you are using, so we can't check exactly what correction facilities are built in. Dbfirs 20:48, 15 November 2014 (UTC)

Yea, the only form of speech recognition that really works well is if it only has to differentiate between a small group of words, like a telephone answering system. When you get to many thousands of words it has to tell apart, it usually fails spectacularly, although training it to your voice helps somewhat. StuRat (talk) 22:01, 15 November 2014 (UTC)

It's at least twelve years since I last spent time training speech recognition software to my voice (and used it to dictate minutes of meetings — a fairly wide vocabulary). I had limited success. For some sentences it was spot on, but for others it made an absolute mess of recognition. I had supposed that some progress might have been made in twelve years, but it seems that the problems are not easy to solve. Dbfirs 23:20, 15 November 2014 (UTC)

Part of the problem is that we all read lips to some extent, as demonstrated by the McGurk effect, so ideally any speech recognition system would need to do the same. (Of course, people do manage to communicate by phone, but misunderstandings are likely more common there.) Then there's some artificial intelligence built into human speech recognition. If we think we hear "I'm going to the store to fry a loaf of bread", that doesn't make any sense, so we mentally correct "fry" to "buy". A good speech recognition system would need to be able to do that, too. StuRat (talk) 01:02, 16 November 2014 (UTC)

Its MS Windows 7 Ultimate, 'Speech Recognition' software, what you can find in the 'Control Panel'. -- (Russell.mo (talk) 13:24, 16 November 2014 (UTC))

Part of the problem is Speech segmentation: A popular example, often quoted in the field, is the phrase "How to wreck a nice beach", which sounds very similar to "How to recognize speech". Vespine (talk) 23:35, 16 November 2014 (UTC)

The short answer is, it's an extremely complex problem and a continuing very active field of research. Vespine (talk) 23:37, 16 November 2014 (UTC)

If you haven't tried, obviously if you can't train the software to work better with your voice, you could try to train your voice to work better with the software. Try to pronounce your words clearly and distinctly and possibly with an American English accent. Vespine (talk) 23:38, 16 November 2014 (UTC)

I've tried it, it behaves like me, always does something else. I try to speak appropriately, still it fails... Is there any software I can download which will function properly? I mean I tried one twelve years ago, it worked brilliantly, my English was worse than how it is now. I was new to computers that time, I forgot the name of the software... -- (Russell.mo (talk) 10:32, 17 November 2014 (UTC))

The best "I talk. It types." software comes from Nuance (used to be known as Dragon or Dragon Naturally Speaking). Anytime someone has a worthwhile competitive product, Nuance buys them. So, you are stuck with Nuance. It is not anywhere close to free. If you don't want to buy it, you can't have it. 209.149.113.112 (talk) 18:08, 17 November 2014 (UTC)

I've just remembered that the success I had with free software was achieved with a separate microphone in a quiet room (and only after what seemed like hours of training). Dbfirs 01:04, 18 November 2014 (UTC)

I have to work with free products atm. Good to know though. Thanks 209.149.113.112. I guess you are right in many ways Dbfirs, I recall possessing a separate microphone and headphone twelve years ago as well as a quite area while I was using a 'speech recognition' software. I'm not doing any of it right now. I have a built-in microphone in a headset, a stick that extends right next to my lips. I guess your suggestion might do the trick with Windows 'Speech Recognition' software; an advantage it possess i.e you can train it... Thanks! -- (Russell.mo (talk) 18:51, 18 November 2014 (UTC))

Thank you all -- (Russell.mo (talk) 18:51, 18 November 2014 (UTC))

Flac to wav

I know that if I were to convert a wav audio file to an mp3, the sound quality of that will be lost forever, meaning that it won't be regained even if I were to try to convert the mp3 file back to the wav format. However, I read that flac and wav formats are different in that flac files are the compressed versions of wav files. Flac files have all the information that a wav file, but in a more compressed scale. However, I've read that wav files tend to sound better for some people. If that's the case, would that mean that the sound quality will be gained back if I were to convert the flac file back to a wav, or would the sound quality of the wav be lost forever as well even if I were to turn the flac file back to a wav, and if so, why? Willminator (talk) 18:42, 15 November 2014 (UTC)

I can think of only three reasons why the FLAC file would sound worse:

1. The FLAC decoder/player is broken.
2. The original WAV file used a format that isn't supported by FLAC, such as floating-point samples, so the conversion to FLAC actually lost information.
3. They're imagining it.

In the first case, you can get the original sound quality by using a non-broken decoder. In the second case, the information is already lost and can't be recovered by any decoder. The third case is the most likely. -- BenRG (talk) 05:44, 16 November 2014 (UTC)

In this case, I tend to agree with BenRG: the user is probably imagining a sound difference. A lot of audiophile claims can be debunked by performing a double blind experiment! But if there really is a perceivable difference, then there is an error in the software. The error might be very subtle, like a rounding-error or a conversion mistake; or something egregious, like a buffer overrun or a real-time performance problem in the player; but when implemented correctly, a wave-form that has been compressed and then decompressed using FLAC is bit-for-bit identical to its original waveform. This hypothetical "error," if it existed, must have slipped past all the FLAC developers, who have strongly asserted that there is no such error.

You can run FLAC with a verbose flag to perform a bit-for-bit check on input and output. If this is insufficient, you can inspect the code yourself. The code base is "fairly small," but I doubt I could verify it in just one afternoon. Personally, I would not try to read the code in its entirety, but I can envision building a version that let me write my own verification suite at key points along the signal's "critical path," (if I were so inclined).

Nimur (talk) 16:49, 16 November 2014 (UTC)

It's definitely not FLAC itself, they have done bit-for-bit comparisons of WAV and WAV-to-FLAC-to-WAV files - and they are indeed identical. It could conceivably be the player - but then there are a large number of WAV players too...if there could be errors in the FLAC player, then there might be similar errors in *some* WAV players. So it would be incorrect to say that WAV sounds better than FLAC - merely that one player sounds better than some other that just happens to load FLAC.

Audiophiles are really becoming tiresome people these days. They used to be people with huge, deep, interesting knowledge of how to squeeze the best from turntables, tape decks and imperfect amplifiers...it was a great hobby. You could argue endlessly about whether putting this head on that turntable with this amplifier and those speakers were better...than whatever the other person had because everything was a compromise of some kind or another. Then, almost overnight, we got digital audio with precisely perfect storage and essentially perfect reproduction - far better than the human ear can resolve - and at a price that even someone who doesn't give a damn about quality is happy to pay. Now those people have nothing left to discuss. So they'll pontificate about the relative merits of things like FLAC and WAV - even though there is no real difference. These are the same people who'll tell you that a $100 USB cable with gold plated connectors produces "more lively vocals with deeper bass resonance overtones"...which is without any shadow of a doubt, complete nonsense. There is no doubt that lossy formats like MP3 do sound SLIGHTLY different from WAV or FLAC - but with a lossless format, there is no way for anyone to tell. SteveBaker (talk) 01:43, 17 November 2014 (UTC)

I mostly agree with SB although I may additionally note that many people with decent equipiment can't tell the difference between sufficiently high bitrate MP3 (which with more modern lossly compression often doesn't have to be that high) with ABX testing. This isn't of course to deny it's frequently possibly by expert listeners with sufficiently good equipement even with very high bitrates. See also Transparency (data compression). Of course, probably at least partially due to the widespread popularity of such lossy formats, some people actually prefer the lossy version when they can hear a difference. See e.g. [5] (I'm surprised no one pointed out that it's fairly unlikely anyone prefers 128-bit (rate) MP3s) but also [6] (only the first part, ignore the second part about 192kb/24bit which appears mostly nonsense as the only commentator pointed out). It's particularly funny when someone who considers themselves an audiophile does so unexpectedly. Actually I'm surprised there isn't a movement like there is for analog limitations and distortians. Nil Einne (talk) 06:18, 17 November 2014 (UTC)

BTW, the hydrogen audio forums [7] and wiki are a IMO a good place for reading discussions related to a lot of things audio as they generally tolerate little nonsense. For example, anyone making a claim about being able to hear something generally at least needs an ABX result or they're given short shrift. Also the 192kb/24bit claim on they audiophile site I linked to is a useful reminder of the problem with many audiophiles. 24bit audio or at least 20 bit audio could theoretically (although evidence for cases when it does is limited) provide detectable sound differences than 16 bit in really extreme cases. Yet many audiophiles are convinced you need 192khz as well, even though it's fairly unlikely any of them can really hear abour 22.05khz (let alone 24khz which 48khz will provide and since they aren't cats the idea 96khz/48khz isn't enough which many of them seem to have, is just silly). Nil Einne (talk) 07:00, 17 November 2014 (UTC)

Also I was reminded of something from this article [8]. My understanding is that although the move to widespready availability of HD audio offers limited technical benefit (except in extreme cases where you really gain an advantage from more than 16 bit, or I guess if you are a cat :-P), there has been some benefits. For older content it may mean remastering using better techniques or equipment. For new content, audio engineers are sometimes less free with compression and other techniques used because they are told or believe they are favoured by the majority, but which many audiophiles (both those who sprout nonsense and those who don't) dislike. Then again, reading a bit more I'm also reminded this demonstrates another problem of the claims of the nonsense audiophiles. A lot of the content they claim is superior with HD audio for technical fidelity capability (and not mastering choice/quality) was recorded with and on equipment and material that probably doesn't even achieve 22.05khz/16 bit (93db or whatever) fidelity, so any alleged advantages can only come from mastering interpolation. I should clarify that I'm only thinking of what format is necessary to relay the audio to a human listener. I'm not denying there may be reasons to capture these details or to use higher fidelity particularly in the mastering stage for various reasons such as rounding errors or if you have other intentions (like if you do want your cat to listen to your audio). E.g. there's one mentioned at the end of [9]. Nil Einne (talk) 07:09, 17 November 2014 (UTC)

This article says that testing have shown that wav tend to sound better than flac. At least some people may not be imagining a sound quality difference. Willminator (talk) 19:00, 17 November 2014 (UTC)

The problem is (and the article actually says as much) that the digital content in FLAC file is bit-for-bit identical to the WAV. And, it goes on to explain (as I did, above) that the difference must be due to the software they used to replay the FLAC and the WAV. These are obviously not identical - so there is a possibility of error in one or the other. Well if that's true - then the problem is that there are MANY WAV players - not just one. So if the WAV player they tested produced different results from the FLAC player they tested - then what they are comparing isn't the file formats - it's the software that's doing the replay. It's very possible that there are different software replay modules for WAV that sound different from each other. Once you know that the two file formats contain the same data, the argument over which is better is done...they are precisely equally "good". What you should be arguing about is which replay software is better...which says nothing whatever about file formats. There may be better FLAC players and worse WAV players than the pair they happened to use. That said, I don't buy that either because the article said that the PCM streams were identical too...they argued that CPU time spent doing decoding was the culprit - but that's bullshit because the timing of the data into the audio DAC is driven by the sound card, not the CPU. If the CPU doesn't make it, you get gigantic and very, very obvious clicks...not so, so subtle differences that only golden-eared audiophiles can pick it up.

So this is still very typical audiophile nonsense. SteveBaker (talk) 17:30, 18 November 2014 (UTC)

Actually, the article makes a good point: computers make noise when they're computing, and that could contaminate the output. You'd have to do a blinded test to be sure, but it sounds more plausible than my first two suggestions. -- BenRG (talk) 19:25, 18 November 2014 (UTC)

November 16

a = help(list.append) and help(list.append)

Why are both method calls the same? Can't the 1st call save the help()? I see that help() returns None, but, what if I wanted to save the text of the help()?--Senteni (talk) 17:02, 16 November 2014 (UTC)

Help prints the docstring, which is a property of the object called __doc__

So you'd do

   a = list.append.__doc__

-- Finlay McWalterᚠTalk 20:22, 16 November 2014 (UTC)

More generally (and for more complicated problems where there isn't a simple string like this to look at) you can capture your programs own prints (to stdout) by temporarily substituting a StringIO object in for sys.stderr. This is overkill for your current problem, but might come in handy later. An example (which accomodates the changes to StringIO done between python2 and python3) is:

import sys
 
try:
    import cStringIO
    new_stdout = cStringIO.StringIO()
except ImportError:
    import io
    new_stdout = io.StringIO()
 
old_stdout = sys.stdout
 
sys.stdout = new_stdout
help(list.append) # stuff that would normally print to stdout, usually the terminal
a = sys.stdout.getvalue()
sys.stdout.close()
sys.stdout = old_stdout
 
print("the output of help was >>{:s}<<".format(a))

-- Finlay McWalterᚠTalk 21:06, 16 November 2014 (UTC)

November 17

Looking for an automatic exposure blending tool

I've recently found a large lot of my family's vintage photos in a garage and I'm currently scanning them. Most of these are snapshots taken throughout the 1930s and 1940s, but turns out that a number of these paper prints are actually exposure bracketing sets of even older photographs, where photographic plates taken c. 1900-1930 (an educated guess rather than a broad one, based not only upon wardrobes and hairdos, but especially the specific ages of family members portrayed which make it clear that some of the photographs are definitely pre-WWI and going up until the late 1920s) were photographed again in order to transfer them from plates to paper prints. Because the images lost a lot of dynamic range in this crude optical copying process, the photographer did exposure bracketing shots of two or three per original plate with a different f-stop each, so that one exposure has good shadows, one good mids, and one good hi-lights, whereas the rest is lost to the single shot.

So now I'm looking for a free exposure blending tool which would combine the dynamic range for every exposure bracketing set (so that it would use the optimal exposure for every area) and export me a tone-mapped regular BMP, TIFF, or JPG on the other side. I've spent three very frustrating hours tonight trying out FDRtools [10] and Enfuse [11] after seeing reviews with rather good example results from these two. But FDRtools always crashes on me with a runtime error when I'm trying to load the images, or, at the very latest, when I'm clicking 'Edit', and Enfuse should rather be called *CON*fuse because it's not really a program, but more of a weird programming language that is *WAY* beyond me. I can't even tell how to make this Enfuse thing operative or access my image files somehow. So, what else would be out there to do this kinda thing? --84.180.255.151 (talk) 00:38, 17 November 2014 (UTC)

Don't know about FDRtools but I found Enfuse pretty simple “ just stupidly followed the instructions”. Are you using Windows or Linux? Think I got the know-how from [12] which is currently down for maintenance so I can't be sure. On (say) Ubuntu's OS (Linux) one just downloads it and it's good to go. Have another try. As the Buddhists recommend: Start with a quite and peaceful mind. More hast equals less speed. --Aspro (talk) 01:52, 17 November 2014 (UTC)

I'm on Windows XP here. Spent 90 minutes on Enfuse now after your encouragement and reading your linked page by means of Wayback. All I manage to do is make Enfuse.exe tell me on double-click that it's not a 32bit application, and when I'm trying to use the droplets, it says it can't find Enfuse.exe anywhere, even if they're in the same folders. --84.180.255.151 (talk) 02:35, 17 November 2014 (UTC)

Uhm. It is well known that Microsoft doesn't like people like you, to use free software! Microsoft would rather you spend £500 on a photo-shop application. So, create a live Ubuntu Linux memory stick and run Ubuntu Linux. That will not affect your XP installation at all . Oh, and the weird programming language your referring to is probably BASH. Forget it. On Ubuntu, just make sure you have the Huggins suite downloaded and installed on Ubuntu then follow this tutorial: Creating HDR Images with Enfuse & Hugin. No programming skill required on Ubuntu. Just switch XP Windows off and then back on again, if anything doesn't go to plan.--Aspro (talk) 02:58, 17 November 2014 (UTC)

Alternatively, you could use a Ubuntu LiveCD [13].--Aspro (talk) 03:06, 17 November 2014 (UTC)

But wouldn't I need a 64bit hardware machine to begin with in order to run such a 64bit application such as Enfuse? --84.180.255.151 (talk) 03:13, 17 November 2014 (UTC)

Enfuse and Hugin have both 32 and 64 bit versions. I currently use them on a 32 bit Dell desktop. --Aspro (talk) 03:23, 17 November 2014 (UTC)

YES!!! A thousand thank yous! I had to google a bit to find the 32bit version (because it's not linked directly from the Enblend-Enfuse main site nor Sourceforge), then fiddle a bit to find out that (other than for instance Mencoder) it only works if both Enfuse.exe and the photos are in the C:/Documents and settings/user directory that I'm prompted in the DOS prompt...but now it *WORKS*! It's amazing to see what tonal range Enfuse can recover by combining three basicly two-value hi-contrast exposures from 70 years ago of the same original plates that in turn were taken a hundred years ago! :D It's just that aligning several paper print scans is a bitch compared to aligning several digital shots taken with a tripod... --84.180.255.151 (talk) 04:16, 17 November 2014 (UTC)

Alternatively, you could use the Hugin GUI which does link to the 32 bit version on the Hugin sourceforge site and comes with Enblend and Enfuse. Nil Einne (talk) 04:53, 17 November 2014 (UTC)

BTW, you appear to be correct that the Enblend/Enfuse website doesn't seem to link to 32 bit version in any real way. The simplest way when this is a problem on Sourceforge is IMO to look for it yourself. An easy way to find it is if you click on the download link, this will normally take you to a download page which will tell you the download is starting soon. Click on the project name (Enblend in this case). This will take you to the project reprository e.g. [14] for 'Enblend'. You should see some links like 'summary', 'files', 'reviews' along a line somewhere in the middle or middle top of the page (below the non project Sourceforge stuff). If you click on 'files', you will be taken to the reprository. Sometimes the reprository may be a bit confusing, but you can often tell by the date and name where to look. Don't be afraid to use the back button if you end up at the wrong place. Alternatively, if you hover over the link for the latest version, you can see where that is and guess where to look. In this case if you click on 'enblend-enfuse' and then 'enblend-enfuse-4.1' you will end up [15] where you can find the 32 bit and 64 bit. I found the Hugin 2014.0 and 2013.0 links the same way before I noticed the 2013.0 was linked on the main Hugin page and it isn't unheard of for software to only provide the source tarball even if a precompiled binary exists and sometimes you may be looking for older versions, or RC version or whatever which often aren't well linked, so it's helpful to know how to navigate the Sourceforge reprository in any case. Nil Einne (talk) 05:08, 17 November 2014 (UTC)

(EC) You can download a 32 bit Windows binary of Hugin here [16] or here [17] depending on whether you want a an RC version or the latest non testing version. The later link BTW is under the "Pre-compiled versions" section under Windows: Official 2013.0.0. I don't have a Windows XP install to test, but I'm fairly sure it will just work if you get the right version. Considering the details here, I would suggest the non Python installer (i.e. RC4 or latest nontesting).

BTW, the reason why it didn't work here doesn't seem to have anything to do with any Microsoft dislike for free software (unless you count the lack of a package manager or simple way to compile stuff from source, but I think even many non technical *nix users find compiling stuff from source often isn't so simple hence the proliferation of package managers), but all to do with the fact Sourceforge didn't provide the right version. From my own testing, I think it doesn't detect whether you have a 32 bit or 64 bit version of Windows only that you have Windows and so provides you the 64 bit version, I'm guessing based on the choices of the Hugin sourceforce maintainer as the default version for Windows. The reason may be because while there are ways to try and detect 64 bit (whether browser is 32 bit or 64 bit) vs 32 bit Windows via the useragent these may not be entirely reliable.

You can perhaps partially blame Microsoft here in that while they did stuff a certain way in IE e.g. [18] & [19] and many followed, I'm not sure if they ever published this as a recommendation for others to follow. Also it seems there are some cases when even IE may provide no clue the OS is 64 bit, although I'm not sure that people using Enterprise mode are likely to be a significant concern for providing the right version for software install. And I'm not sure whether Apple would have followed Microsofts recommendations in Safari Windows even if they did exist. Or for that matter, even if there was an entirely reliable way to detect Windows bitness from the useragent, SourceForge would use it.

You can perhaps also fault Microsoft for not allowing universal binaries, but there a number of reasons why they may have chosen not to do so, and it's unlikely free software considerations even came in to them. (And I'm fairly sure software providers could simply use a 32 bit shim which chooses whether to install a 64 bit or 32 bit version.)

Edit, oh except for the links, this seems to mostly apply to Enblend/Enfuse as wellNil Einne (talk) 04:51, 17 November 2014 (UTC)

Ah. image alignment !

If the OP has many photos, then it would be worth installing GIMP (free) and then the Gimp Plug-in for Image Registration (free). Both are a must have if one can not justify the cost of Photoshop.--Aspro (talk) 20:38, 20 November 2014 (UTC)

Google Chrome's sound tracker for noisy tabs

http://chrome.blogspot.ca/2014/01/everyone-can-now-track-down-noisy-tabs.html

What ever happened to this feature? I remember seeing it run nearly a year ago, but then forgot about it. Has it been dropped or made to require manual activation? I'm using the Dev release, which should have the same content than the Beta one. ~­Matt714 (talk)

I use the current consumer version Chrome and I see it all the time. Maybe its a setting on your end? KonveyorBelt 02:57, 17 November 2014 (UTC)

Can you tell us a little more about the exact version of the dev Chrome and your environment? I have these icons showing right now by default on Chrome 38 in Windows 7. Freedomlinux (talk) 03:02, 17 November 2014 (UTC)

Windows 7 64 bits - Chrome: Version 40.0.2214.6 dev-m (64-bit) - Nevermind, it still works. However it's not as clear than when it was animated. Matt714 (talk) 17:34, 17 November 2014 (UTC)

November 18

Changing MediaWiki's version control mechanism.

(This is not a question about Wikipedia!)

I'm looking for a plugin/extension or perhaps an outright modification that would allow me to use an alternative version control system to MediaWiki's "history".

Specifically, I want to be able to change the way that 'diff' is done - but I'd also like to use something more like GitHub.

Googling for this is near-impossble because all you get is protracted debates amongst the MediaWiki developers about which version control system they should use for the software behind MediaWiki and it's extensions. I'm interested in versioning the content stored INSIDE MediaWiki.

If there isn't a plugin - I'd be interested in any tips about where to find all this stuff in the MediaWiki source code so I can attempt a "Do It Yourself" approach.

TIA SteveBaker (talk) 17:12, 18 November 2014 (UTC)

(edit conflict) You're talking about the backing store, i.e., the database. In Manual:Installing_MediaWiki#Create_a_database a standard MediaWiki installation, that database is usually MySQL or PostgreSQL, or something equally suitable for SQL data archival. You're talking about retrieving the content out of, say, a git or subversion repository: that would not work out of the box. MediaWiki expects to speak SQL to its backing store. You would need something - either a modification of the MediaWiki PHP source, or some "interposer" program that pretends to speak SQL while actually committing the data to, say, a subversion server. Nimur (talk) 17:30, 18 November 2014 (UTC)

Have you looked through mw:Manual:Extensions you might find something there. I suspect that changing the way a diff is done would be relatively easy, changing how revisions are manage is a much more complex task involving changing the database tables used. Perhaps mw:Extension:Diff, mw:Visual_Diff mw:Extension:Wikidiff2 mw:Extension:Wikidiff.--Salix alba (talk): 17:28, 18 November 2014 (UTC)

@Nimur: I confess to being not super-familiar with SQL either (although I have a sense that I'm about to become that!)...so am I right in saying that SQL has some kind of native revision history - and MediaWiki is just using it? Or is it a case of MediaWiki creating a sequence of time-stamped data records which it's using to create a revision history that just happens to be stored by SQL?

MediaWiki creates a sequence of time-stamped data records. See: Database Access in the MediaWiki manual, and tables.sql, the code that defines the database layout of a clean MediaWiki installation. Each historical revision of a Wiki page on MediaWiki is an instance of a revision (i.e., a "row" in the revision table); that revision has pointers to the historical textual content (e.g., the rev_text_id, and so on). Nimur (talk) 22:19, 18 November 2014 (UTC)

@Salix: Thanks for the "diff" stuff - I think that'll answer that part of my question once I get a chance to wade through it all! SteveBaker (talk) 18:39, 18 November 2014 (UTC)

Trying to understand Python syntax

This is related to this question. In File:Poisson_pmf.svg there is a line: "a = plt.plot(X, P, 'o', color=col[L])". why does it perform an action (plotting the stuff), and get assigned to a variable? I'd expect the method call only to be assigned to the variable 'a' (and do nothing yet, just hold the object). However, "a = plt.plot" and "plt.plot" have the same effect (on the plot, I see that later they need the 'a' for the legend). I just don't get that you don't have to write two independent lines. First, "plt.plot(X, P, 'o', color=col[L])" and then "a = plt.plot(X, P, 'o', color=col[L])".--Senteni (talk) 17:29, 18 November 2014 (UTC)

First, I've taken the liberty of fixing your wiki-links.

To directly answer your question: these two lines are actually creating two different plot objects. It is perfectly legal in Python (and almost all other programming languages) for a function to do something and also to return a value. In this case, the return-value of the plot function is an object pointer to an object that stores information about the plot.

Nimur (talk) 17:33, 18 November 2014 (UTC)

Ok, but what if you wanted to store a function to a variable, not run it and get the return value? Would that be possible and meaningful?

You can take a function and some parameters and glue them together into another function, a reference to which you can store in a variable and then subsequently call (typicaly then supplying the remaining paramters you didn't do when you glued up the partial). The documentation for functools.partial gives an example here. -- Finlay McWalterᚠTalk 17:52, 18 November 2014 (UTC)

In Python (and many more modern languages with functional features) you can refer to a function (a = plt.plot) or call it and use the return value (a = plt.plot(...) - note the parenthesis with (elided) parameters here). And you can make ad-hoc functions, too: a = lambda x:x+10 will assign a function of one variable to a (and that function will return its argument plus 10 if called). --Stephan Schulz (talk) 18:03, 18 November 2014 (UTC)

Hmm, but matplotlib plot calls are methods on the plt object (they mutate its state), they're not pure functions. I think taking a partial of a method may essentially unbind it (lose its association with the plt object) so that's probably not what you want to do. -- Finlay McWalterᚠTalk 18:07, 18 November 2014 (UTC)

I would need to think about this. But what you certainly can do is use a lambda again: a = lambda x:plt.plot(x) (substitute parameters as needed ;-). --Stephan Schulz (talk) 19:08, 18 November 2014 (UTC)

In contrast to some other languages, plt.plot behaves sensibly in Python. If you assign plt.plot to f then f(*args) is equivalent to plt.plot(*args). If plot is defined in Cls then plt.plot is equivalent to partial(Cls.plot, plt), and partial(plt.plot, arg) is equivalent to partial(Cls.plot, plt, arg) and so on. -- BenRG (talk) 19:17, 18 November 2014 (UTC)

November 19

WiFi hot spots

I want to change ISP. However, our current ISP has about 100 Wi-Fi Hot Spots in the city and the other one has about 10. This doesn't matter to me, but it does to my wife. I understand that the range is maybe 50 meters. Is there something at a reasonable cost that will allow her to access the WiFi, for the one with only a few hot spots? Bubba73 ^{You talkin' to me?} 04:38, 19 November 2014 (UTC)

I'm not sure I understand the issue. I can go to Starbucks and use their hotspot, whether or not the ISP I use at home is the same ISP that Starbucks uses. Starbucks grants me free access to the Internet through their ISP. If she has some software on her laptop/smartphone that ties her to one ISP, she should get rid of it. ‑‑Mandruss ☎ 05:01, 19 November 2014 (UTC)

I don't really understand the system, since I don't have a wireless mobile device, except my plain telephone. When I suggested switching, she said "how can I access all of the X hot spots around town?" (where X is our current ISP) I checked online and the one I want to switch to lists only about 10 hotspots - every McDonalds and every Burger King, and not much more. The other one lists about 100. The brochure for the new one (call it Y) says "... accessing the entire national Y Wi-Fi Hot Spot network, which is included with all internet speeds." So to me, that says you can access their hot spots, but it doesn't say about ones from other companies. Should she be able to access all of them? Bubba73 ^{You talkin' to me?} 05:11, 19 November 2014 (UTC)

Every McDonald's that I've encountered uses AT&T for their Wi-Fi. I don't have an AT&T account and that has never stopped me from accessing their hotspot. Nor does it stop anyone else on Verizon, Sprint, etc. I don't see why your wife would be blocked from any of the 110 hotspots. Dismas|^(talk) 05:26, 19 November 2014 (UTC)

Since I wrote my last message, I talked to my daughter. She said that McDonald's uses AT&T (as you said), which is not our current ISP. She says that she just has to go to a login screen - no problem. So I didn't know this stuff, and I think my wife should not be concerned. Bubba73 ^{You talkin' to me?} 05:44, 19 November 2014 (UTC)

Resolved

There are, broadly, two types of hotspots. Free ones, and paid ones. Those supplied by a store (e.g. McDonalds) are generally free, anyone in the store can use them, regardless of whether they have a subscription with the hotspot operator/ISP. Some ISPs or hotspot operators will also have paid hotspots which you can access if you have a subscription with them (either specifically for their hotspot service, or sometimes bundled with your home internet). Chances are that the only hotspots for your new ISP are free ones (given the low number), while the ones for your old ISP are a mix of free and paid hotspots. Other than going to the various places that she wants WiFi access and trying it out without using your ISP login credentials (i.e. making it look as if you're just a random person off the street), there's no surefire way of telling which she'll still be able to use. I'd expect any WiFi in a fast food place or a cafe to be free. MChesterMC (talk) 09:55, 20 November 2014 (UTC)

Why isnt my Java repaint call actually changing the look of my window?

Hello,

For fun i wrote a class that can display random walks, shown here. I will note that for brevity i excluded the "GfxConfigs" class, which only grabs an array of Rectangles that represent each monitor attached to the computer. Notice that i have listeners attached to a window so that when you left click and drag, the window is moved around. Also, when you right click, i intend the program to erase that random walk, and make a new one (I call "repaint").

The new random walk is not generated, although you can see that repaint is called since the program does the println of the string "repainted". What am i doing wrong here?

216.173.144.188 (talk) 20:31, 19 November 2014 (UTC)

Edit: I have added debug println commands which verify that the paint method is called, and a new random walk is generated. The change just isn't being shown! It will "work" if i do this:

   w.repaint();
   w.setVisible(false);
   w.setVisible(true);

... But i don't want to accept this as the fix, because it kills the symptoms and not the problem, and it also makes my random walks disappear for a short time when right clicked. 216.173.144.188 (talk) 22:01, 19 November 2014 (UTC)

November 20

Dates of 'Friend requests' in Facebook

How can I get this data, which is of basic nature, with respect to when these requests were sent to me ? Strange they've left this basic issue in a childish condition. I've raised this question there ('Help Community'), already, with no answers, as yet. BentzyCo (talk) 01:23, 20 November 2014 (UTC)

SO BASIC, BUT YET, SO COMPLICATED. Why designed so ? BentzyCo (talk) 06:43, 21 November 2014 (UTC)

Looking for an IEEE paper

I'm looking for the paper: A classification of CASE technology by A. Fuggetta. Here is a link to where the paper can be found:

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=247645&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel1%2F2%2F6338%2F00247645.pdf%3Farnumber%3D247645

I created a user ID on the IEEE site but without an institutional ID they make you pay for to download the paper. I need the paper to edit this article: Computer aided software engineering It's used as one of the primary references for many of the fundamental claims in the article. I think all the claims are true and probably backed up by the paper but want to be sure and also want to expand and edit the article to address the concerns in the tags. Also, on the Talk page of that article people have mentioned the idea of creating new articles that distinguish different subdomains of CASE (e.g. upper CASE vs. lower CASE) and I think this paper would be an excellent source if we do that. --MadScientistX11 (talk) 17:31, 20 November 2014 (UTC)

The place to ask for this is WP:REX. If you don't get any help there you can ask me on my talk page. SemanticMantis (talk) 20:08, 20 November 2014 (UTC)

In Python, where does the return output go, if you don't care about it?

In

   plt.plot(X, P, '-', color='grey')
   a = plt.plot(X, P, 'o', color=col[L])

from File:Poisson_pmf.svg. I see that both lines perform an action, but the second returns a value that gets used further. Where does the return value of the first go to? Does it just silently disappear without any side-effects? And would that be a problem, if you get really lots of these dismissed values? --Senteni (talk) 17:40, 20 November 2014 (UTC)

I don't know - but I know that this question goes on the computer reference desk. AndyTheGrump (talk) 17:46, 20 November 2014 (UTC)

The answer is pretty ... uh, "heavy...": the answer to these sorts of questions might not be very accessible to new programmers. How much do you know about compiler theory, and how much do you want to learn?

Both statements contain Python expressions and the latter statement is also an assignment statement. An assignment statement causes the interpreter to bind a value to a name. If the value is not bound, it is up to the Python interpreter environment to determine its scope and persistence behavior. In CPython (the most common implementation of Python), that value is stored in a reference-counted dictionary, and because it is unbound, it will be re-collected by the Python memory manager "very soon." In CPython, that garbage collection occurs when the value goes out of scope (which is, in a sense, a less memory-optimized sequence compared to the behavior of most compiled machine-code, in which an intermediate unbound value will cease to exist as soon as the CPU micro-architecture wants to re-use its hardware storage). Python's interpreter is, in a sense, a virtual machine; and the data-persistence of intermediate values is completely controlled by the software-implementation of the interpreter.

More to the point, "who cares" about how Python code interplays with the microarchitecture of compiled code? Well, you'll care if you ever try to embed the Python interpreter into your own code! Suppose you wanted to make a game, and you choose to implement the game in C code, but you want to permit the higher-level game logic to take the form of a Python script. Suddenly, the performance and data-persistence of the interpreted script can make a big difference! (As an actual example, Firaxis embedded Python into Civilization 4 and performance reviewers were not kind).

If you're into this stuff, the book you want is: Computer Organization and Design: The Hardware/Software Interface. Read that one over the course of a year; and then grab a copy of the CPython source and your favorite processor reference manual...

Nimur (talk) 18:20, 20 November 2014 (UTC)

VCARD file syntax for obsolete and emergency contacts "not to be normally used"

I'm trying to understand the syntax and approach used with Vcard, when handling obsolete and emergency contact data. In the real world, obsolete contact data can be important - but it can also be very important to ensure it is clearly not to be used.

Example: Contact "Jane" has used the following 5 phone numbers -

• 123-1000, main home phone number (voice service)
• 456-1000, cellphone (voice, text services, preferred contact)
• 876-1000, a previous phone number, before she moved out of her old home. This is never to be called, even by accident, as it's obsolete, but deleting it would mean that all call history to and from that number would no longer be identified with Jane. Her 'ex' also still lives at that number so it's important to recognize it, if it ever rings and even if it's never used.
• 765-1000, another previous phone number, now reallocated by the telco to unconnected subscribers, but likewise if it's deleted then old and important records related to that contact number won't be linked to Jane.
• 333-1000, her medical emergency contact service for some condition Jane may have. Never to be called except in emergency as they charge $150 per call on each occasion used.

I'm trying to understand what provision VCard includes, or how VCard entries are structured, to reflect that very often, numbers need to be "on file" for a contact even though "obsolete" or "emergency", and how a number of this kind is represented in a typical handset's Vcard if it's needed but never normally to be actually dialed. In particular how one tags a number if it must be recognized but also mustn't be allowed to be dialed even accidentally. FT2 ^{(Talk | email)} 23:24, 20 November 2014 (UTC)

VPN Protocol

When I use public WiFI I always connect to a VPN. I either use OpenVPN or L2TP/IPSEC PSK. Which one would be less likely or harder to block? Also, sometimes I cannot access Google services while on OpenVPN TCP443. Why? I can access Google services on UDP1194 or L2TP/IPSEC PSK, but sometimes not TCP443. pcfan500 (talk) 06:58, 21 November 2014 (UTC)