Wikipedia:Reference desk/Computing

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September 21[edit]

What's the first year when even a phone can "play Crysis"?*[edit]

*Meaning the phone has the specs of a PC that can do it (never dipping below 30 fps @ 1440p while almost visually indistinguishable from max settings), not necessarily that PC-strength Crysis for its OS exists. Sagittarian Milky Way (talk) 03:25, 21 September 2016 (UTC)

Theoretically a high-end SOC can run the game (assuming Crytek ported it optimally), but not on the settings as you described. Bioshock for the iOS tried to replicate the original experience on a mobile setting, but while it is more or less possible to get it to run unabridged some technical sacrifices had to be made. Blake Gripling (talk) 03:31, 21 September 2016 (UTC)

If Lisp is founded on lambda calculus, what's the foundation of other programming languages?[edit]

I hear that lambda calculus is the model of computation at the foundation of Lisp. That makes me wonder what's the foundation of the other mainstream languages like C, Java, Python, JS, Perl and so on. --Llaanngg (talk) 15:56, 21 September 2016 (UTC)

Most of the programming-languages that you have listed target abstract machines of the Von Neumann architecture. The underpinning of this architecture is the stored program, composed of executable data, whose sole purpose is to transform input-data into output-data.
You can chase down all the theories that can be used to describe such machines; but how you choose to classify these theoretical underpinnings is purely a question of finding your favorite taxonomical scheme. You will find recurring themes related to discrete mathematics, finite state machines, and the mathematics of digital logic.
Nimur (talk) 21:23, 21 September 2016 (UTC)
The register machine? I asked something similar a while (3 years) ago: [1]. Asmrulz (talk) 05:28, 22 September 2016 (UTC)
The foundation of Perl was wanting to create a better AWK and sed. I think all those models (Turing machine, Lambda calculus... string rewriting) don't even figure into language designers' motivations. In imperative languages in particular, once you have ifs and gotos in it, you just know it's Turing complete and can do anything Asmrulz (talk) 06:07, 22 September 2016 (UTC)

Template drop-down not working in new chrome[edit]

Me and my friend's cite>template drop-down menus aren't working in the new chrome (53.0.2785.116 m (64-bit)). I tried clearing my cache, but it didn't change anything. However, when I access Wikipedia from an incognito, the template drop-down menu works for me. Has anyone else encountered this issue? Do you have any ideas about what might be causing it? Thanks, Rachel Helps (BYU) (talk) 19:37, 21 September 2016 (UTC)

It works fine for me. Can you report what you see in the browser console? (Ctrl+Shift+I -> Console) Ruslik_Zero 20:48, 21 September 2016 (UTC)
Yes, @Ruslik0: it says the following:
<blockquote*This page is using the deprecated ResourceLoader module "jquery.ui.widget".
  • VM120:117 This page is using the deprecated ResourceLoader module "jquery.ui.position".
  • VM120:514 This page is using the deprecated ResourceLoader module "jquery.effects.core".
  • VM120:482 This page is using the deprecated ResourceLoader module "jquery.tipsy".
  • VM120:72 This page is using the deprecated ResourceLoader module "jquery.ui.core".
  • Please use "mediawiki.ui.button" or "oojs-ui" instead.
It looks like the template drop-down is going under the text editing area, if that helps. Rachel Helps (BYU) (talk) 16:16, 22 September 2016 (UTC)
You can start with disabling all gadgets and blanking your common.js/vector.js files. If this helps you should re-enable them one by one until you find a culprit. Ruslik_Zero 17:49, 22 September 2016 (UTC)
Thank you for you help! It was the syntax highlighter. Someone else has already reported the issue in the right place. Rachel Helps (BYU) (talk) 19:24, 22 September 2016 (UTC)

September 22[edit]

Xidel help[edit]

Using xidel how would you extract only the "no" data from this json feed? The feed contains 150 items each with "no" and "last_modified". I want only the "no" data returned for all 150 items,

For example


etc would become;


etc. I tried reading the manual and readme text but I just can't work out the syntax and I have no experience with json. Thanks for your help! (talk) 20:40, 22 September 2016 (UTC) (Copied from WT:RD edit request. -- ToE 22:49, 22 September 2016 (UTC))

Have you tried:
xidel -e '$json/threads/no'
For syntax utilizing other JSON notation, see #11 under -- ToE 12:32, 23 September 2016 (UTC)
Following myself up, the XPath-like notation above (-e '$json/threads/no') seems to work on my system and do just what you want, but the other two notations -- JSONiq (-e '$json("threads")("no")') and dot (-e '($json)') -- yield no output. I don't know anything more about this as I just installed xidel to see if I could help answer your question. I may be missing something simple. -- ToE 17:11, 23 September 2016 (UTC)

September 23[edit]

Icons suddenly changed in XP[edit]


Why did my icons suddenly get teeny? The were big like A and now went small and on a slice of paper like B. Thanks if for any help. Anna Frodesiak (talk) 06:43, 23 September 2016 (UTC) This has happened to media file icons after I messed around with file associations for VLC and Media Player Classic. Anna Frodesiak (talk) 06:45, 23 September 2016 (UTC)

Where are you seeing them? If it's in Windows Explorer, there's a view option that lets you select how you want to see them (big icons, little icons, tiles, details, etc.) Matt Deres (talk) 16:54, 23 September 2016 (UTC)
It's also possible that changing the file association has the side effect of resetting the icon to the default size. StuRat (talk) 18:44, 23 September 2016 (UTC)
@Matt Deres and StuRat: It's in Windows Explorer and also my preferred FreeCommander. I monkeyed around more with Media Player Classic and those icons went back to regular size. The VLC ones are still teeny, but I imagine it will eventually sort itself out after a while. Many thanks. :) Anna Frodesiak (talk) 22:58, 23 September 2016 (UTC)
Anna Frodesiak, when displayed icons change, kill the hidden file of the iconcache database, located anywhere in the local or temp folder of an users or systems profile. The icon cache wil be rebuilt automaticly, but this is noting to do with the size. It is recommended when the wrong icon to a file or link is displayed. --Hans Haase (有问题吗) 12:57, 25 September 2016 (UTC)

(Windows 10­) GUI program/script to list folders where queried file is missing?[edit]

Greeting friends,

(Win10) basically I want to exclude hidden files from the results of the following* algorithm. Can this be done? Moreover, if it possible, I’d like to exclude the parent folders from the code. Namely, I don’t want D:\backup music\ARTIST, conversely to D:\backup music\ARTIST\ALBUM. Thanks!

for /r “D:\backup music” %i in (.) do @if not exist "%i\folder.jpg" echo %i (talk) 20:29, 23 September 2016 (UTC)

September 24[edit]

Y Matching Paint Tool[edit]

I used to have a program, like paint, that, when you selected a colour, could match the luma of any point you drew. Essentially, it would change the colour, but keep the shading. I cannot figure out what program this was, if you know of any programs that can do this, it would be wonderful. I need to recolour a bunch of sprites for a game I'm working on, it is very tedious doing it without this. Thank you for any help:-) Phoenixia1177 (talk) 00:31, 24 September 2016 (UTC)

You mean the luminosity in the Hue-Saturation-Luminosity model ? I should think any number of programs would do that. StuRat (talk) 01:22, 24 September 2016 (UTC)
You are correct, the draw and paint tools matched the y in yuv. Do you know of any programs that can do this easily, preferably free ones. (talk) 01:27, 24 September 2016 (UTC)
ImageMagick, but it's command-line only. Here are example invocations to change the H,S and L channels individually Asmrulz (talk) 03:09, 24 September 2016 (UTC)
I think I'm poorly explaining what I'm looking for. You know how you can pick the pencil in mspaint and draw with it? In this program, you could do the exact same thing, select Y matching, then, if you click on a pixel it will change it to the colour selected, but keep the luma the same. So, for example, if you had the colour green selected and clicked on a pink pixel, it would turn it to a green pixel with the same brightness as it had when pink. In short, this made recolouring sprites easier since you could change the colour of the hair without having to worry about how bright each pixel was, you just picked a colour and applied it, pixel by pixel. (talk) 03:16, 24 September 2016 (UTC)
I found it, Ultimate Paint has this feature as part of its fill dialogue. (talk) 03:38, 24 September 2016 (UTC)

email addresses on Apple 'Mail'[edit]

I have a number of different addresses and want to close/remove them so that I do not receive mail sent to those addesses, how do I do that please? Artjo (talk) 13:26, 24 September 2016 (UTC)

@Artjo:Are you looking to close the email boxes completely with their constituent services, if so, you would go to those services and request to close your account. If you simply want to delete the accounts from Mail in macOS, go to SYSTEM PREFRENCES → INTERNET ACCOUNT. You will be able to delete or adjust your email account settings there.--Adam in MO Talk 21:41, 25 September 2016 (UTC)

Permissions expressed in code[edit]

I've noticed that two software platforms that use permissions, a model of security that seems to be taking off, don't use plain labels to mark the, but instead use language objects or classes to signify them. I'm talking about Android and Java. These permissions are associated with source code, but I don't get how expressing the permissions in the code that is managed by a runtime works or why it is necessary. How does the inclusion of a permission's class in a program provide security when anyone can just include it in their code? More over, how does that relate to the runtime that monitors what an application does to sandbox it with a particular set of permissions? — Melab±1 20:23, 24 September 2016 (UTC)

September 25[edit]

Does Google Earth "photoshop" trees?[edit]

I was looking at Google Earth for coordinates 35°17′44″N 80°43′37″W / 35.29543°N 80.72707°W / 35.29543; -80.72707. When I zoomed in all the way, the tops of some of the trees didn't look natural, as if they were digitally altered. Does Google Earth do this, and why? ―Mandruss  07:20, 25 September 2016 (UTC)

Update: Ok this appears to be part of their "3D" feature, but I don't see why they would have to do it in the 2D mode. ―Mandruss  07:48, 25 September 2016 (UTC)

I've seen them do that on lawns, too. It might be a form of compression. That is, once the software recognizes a tree or lawn, rather than store every leaf or blade of grass, it just notes that region as tree or grass, then redraws it, using a standard texture, when viewed. StuRat (talk) 14:57, 25 September 2016 (UTC)
Photoshop is one particular brand of commercial image processing software; but image processing is a technique that is certainly used in many other applications, including GIS (digital mapping). In fact, GIS was one of the first applications of digital image processing. The first digital cameras were intended for surveillance satellites; the first algorithmic processing of digital imagery was intended for automating aerial images and maps; long before consumer photographers were "photo-shopping," scientists and spies were using computerized image algorithms to process aerial photographs. It's an absolute certainty that modern digital mapping companies like Google (and their data providers) use sophisticated algorithms to analyze and retouch their map imagery.
In Google Earth Engine documentation, Google explains many algorithms they make available to the public: for example, Landsat-specific postprocessing algorithms are explained. They also use sophisticated methods of machine learning to classify and segment the photographs; to discard poor imagery; to retouch, re-expose, and color-balance the pictures; and to compress and rescale the pictures. Surely Google has even more technology that could be applied to imagery that you see on their final products, even if the explanation and method is not made available to the public.
You specifically mentioned tree-tops; trees are a unique thing in aerial digital images. Find any good book on aerial photography, and you'll get chapters on methods for "foliage." There are algorithmic- and image-capture- techniques to see through foliage; to make foliage appear incredibly bright with respect to the surroundings; to use the foliage to analyze climate, water, industrial activity; to monitor seasonal changes in the treetops... the list goes on and on. Once again, it is a near certainty that "tree tops" are algorithmically altered.
Here's one of my favorite papers on digital photography: Multisensor Fusion with Hyperspectral Imaging Data: Detection and Classification. It's a sort of a review paper on how this all works. For those of you stuck on the ground, just remember - even though you can't see the surveillance planes, the surveillance planes can absolutely see you, and their powerful computers can automatically tell what type of tree you're hiding inside of, too.
Nimur (talk) 21:49, 25 September 2016 (UTC)
I put "photoshop" in quotes because I didn't mean it literally. To my amateur mind that is an approximate synonym for digital image alteration. Look at the white water tower to the east. That is not the actual photographic image of that tower, but a simulated one to enable viewing it from any angle in the "3D" mode (except from underneath, I assume). Google Earth uses this technique with "hard" structures all over the world (which is cool). You look at Notre Dame Cathedral, and what you're actually seeing is a digital "cartoon" representation of the structure. I can see why they would do that for trees as well, but I don't see why they can't show me the real and true photographic version in 2D mode. ―Mandruss  21:51, 25 September 2016 (UTC)
Indeed, Google and other major vendors sometimes use a human artist to "retouch" a complicated scene using 3D models or manual digital image alteration. I wouldn't try to speculate about any particular instance, except to mention that Google has the financial resources to hire individual human artists, at scale, for re-touching their maps imagery; but Google also has sophisticated computer algorithms that may do re-touching automatically. In still other cases, you might be seeing a complicated algorithmic or image-capture "glitch" and projecting your own interpretation onto the image defect. All of these are possible. Nimur (talk) 22:01, 25 September 2016 (UTC)

which country is lagrget in the world[edit]

which country is lagrget in the world — Preceding unsigned comment added by Vìvek Dahal (talkcontribs) 15:19, 25 September 2016 (UTC)

By population, China. By area, Russia. StuRat (talk) 15:45, 25 September 2016 (UTC)
You may be interested in List of sovereign states and dependencies by area from Category:Lists of countries by geography and List of countries and dependencies by population from Category:Lists of countries by population as well as other lists from Category:Lists of countries. -- ToE 21:11, 25 September 2016 (UTC)
Mexico is the largest citizen (obesity) in the world. (talk) 01:46, 26 September 2016 (UTC)
Mexico isn't even in the top 29 of obesity rates: [1]. I would have expected the US to top the list, but small pacific islands and rich Middle-East states seem to have taken the lead. ("I'll take a pass on the poi, please.") StuRat (talk) 02:53, 26 September 2016 (UTC)

September 26[edit]