Wikipedia:Reference desk/Computing

Welcome to the computing section
of the Wikipedia reference desk.

skip to bottom

Select a section:

• Computing
• Entertainment
• Humanities
• Language
• Mathematics
• Science
• Miscellaneous
• Archives

Want a faster answer?

Main page: Help searching Wikipedia

   

How can I get my question answered?

• Select the section of the desk that best fits the general topic of your question (see the navigation column to the right).
• Post your question to only one section, providing a short header that gives the topic of your question.
• Type '~~~~' (that is, four tilde characters) at the end – this signs and dates your contribution so we know who wrote what and when.
• Don't post personal contact information – it will be removed. Any answers will be provided here.
• Please be as specific as possible, and include all relevant context – the usefulness of answers may depend on the context.
• 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.
  • We don't conduct original research or provide a free source of ideas, but we'll help you find information you need.

Ready? Ask a new question!

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.

See also:

• Teahouse
• Help desk
• Village pump
• Help manual

July 29

Extracting tagged text

What algorithm can I use to, for example, extract "abc" from "xxx<abc>yyy" if I give it "<" and "> as delimiters (or another, extracting mediawiki style templates)? What is the most efficient way to do this? 24.255.17.182 (talk) 01:33, 29 July 2015 (UTC)

The usual way of completing this sort of task is to use a Regular expression.--Phil Holmes (talk) 07:04, 29 July 2015 (UTC)

• sed -e 's/[^<]*<\([^>]*\)>.*$/\1/' or something like that will extract one occurence. Graeme Bartlett (talk) 11:04, 29 July 2015 (UTC)
• sed -e 's/[^<]*<//' -e 's/>[^<]*<//g' -e 's/>[^<]*$//' will extract multiples in one line (as long as it is well formed). Graeme Bartlett (talk) 11:12, 29 July 2015 (UTC)

Right, that's sed, available by default on Unix (including OS X), and Linux systems, Windows users commonly access it via cygwin. Some text editors also have built-in regular expression support. SemanticMantis (talk) 13:12, 29 July 2015 (UTC)

The "algorithm" is very simple. Given a value START as the start character and END as the end character, then a STRING as the string of text:

1. Make an empty string DEST.
2. Set a flag TAG to false (or zero).
3. Set a pointer to the first position of STRING.
4. Set CHR to be the character in STRING at the pointer.
5. If TAG is true:
   1. If CHR equals END, set TAG to false
6. Otherwise (else):
   1. If CHR equals START, set TAG to true
   2. Otherwise (else), append CHR to the end of DEST
7. If the pointer is not at the end of STRING, increment the pointer to the next character in STRING and go to 4.
8. DEST contains all chracters in STRING, omitting everything found from START to END.

This algorithm does not handle escape characters. It is not better than a regex as it is the algorithm used by regex. 209.149.113.45 (talk) 13:36, 29 July 2015 (UTC)

Release data of Raspberry Pi 2 Windows 10 ARM port?

Hello everyone. Does anyone know when the free ARM port of Windows 10 for the Raspberry Pi 2 will be released? I would imagine it wpuld have been released when Windows 10 it self was released right? Thanks for your help in advance. —SGA314 I am not available on weekends (talk) 14:33, 29 July 2015 (UTC)

Information about this Microsoft port is available through their developer program: Windows for IoT, as announced in Windows 10 Coming to Raspberry Pi 2, a February 2015 blog update. Here are instructions: Setting up Raspberry Pi. Here are downloadable files. If you aren't already in the developer program, consider joining; they'll give you first-hand news and information long before it hits a wider audience. Nimur (talk) 14:45, 29 July 2015 (UTC)

Ok cool. so it has released already. Here is question 2. I have only 1 32gb sd card. So how would I setup the pi to dual boot off the sd card? For instance, on a pc you can set it up to boot into Linux or Windows on the same hard drive. How would I do this with Raspbian and Windows 10 n the Pi's sd card? —SGA314 I am not available on weekends (talk) 15:57, 29 July 2015 (UTC)

Glympse or alternative

Background: I will be an adjunct at another university this fall. It is a little over 1 hour's drive away. I will be giving myself 1.5 hours to drive there, but in that long of a trip, there is a high possibility of traffic issues. The class period is 1.5 hours. I don't want the students to walk out after 10 minutes if I am just 5 minutes away. But, how do I let them know if I am close or still very far away? Question: Is there an application that will share my location for a certain period of time with anyone and everyone in the world? I don't want to deal with having students sign up for a service and then become "friends" in the service and then install apps on their phones and then lose their passwords and have to reset them every class... I want to turn on an application on my phone and then anyone who knows something, such as my user ID, can see where I am until I turn the application off. I looked into the following:

• Google Maps: I don't see how to share a "here I am" pin automatically.
• Life360: I can only share with my "family" or "circle". So, everyone has to have an account and install Life360 to see me.
• Glympse: This looks promising, but they have almost no documentation on their website. There is a video, but I don't watch videos. I am not illiterate and I don't have time to waste when I could quickly scan text (if there was text) ... trying to avoid a rant about the general shift of the Internet to publishing all information in videos instead of text.

So, any suggestions? On my end, I have a lot of resources. I own multiple web servers. I have an Android phone with GPS and I doubled the battery (screw the warranty). I have handheld GPS device that has WiFi. I can write my own Android app, but I would like to avoid doing so if someone else already wrote something that does this. 209.149.113.45 (talk) 15:13, 29 July 2015 (UTC)

For a decidedly "old school" approach, you might consider walkie-talkies. Although they claim ranges up to 30 miles, the longest you are likely to get is about 2 miles: [1]. Still, if you are pulling into the parking lot 5 minutes after the class starts, you should be able to use the walkie-talkie to tell everyone you are almost there. The advantage: You wouldn't have to rely on anyone checking anything, just leave the other unit plugged into it's charger and turned on in the classroom, and it will speak when you speak on your unit, without anyone having to answer it or check anything. If theft is a concern, I suppose you could lock it up in such a way that it can still be heard (in a metal cage ?).

I also agree that video sucks for giving info. When somebody asks or "answers" a Q here with a 2 hour video and no time index, I rarely bother to watch it. StuRat (talk) 17:08, 29 July 2015 (UTC)

I don't own the classroom. So, I would be dependent on one student to always be in the class with the other handset. Optimally, I would like to find something that I can embed in a web page. I own my web servers and I can ask that the first student in the class direct the overhead projector to my website, which would then have a map showing where I am - along with notes that I can update every day, indicating what they can do while I'm stuck in traffic. 209.149.113.45 (talk) 17:14, 29 July 2015 (UTC)

Set up a webpage someplace - write yourself a tiny Android app that sends the amount of time until your arrival to the server. All you have to tell your students is the URL. Doing this without the app is plausible - but if you're driving, you'll want something that's as close to one tap on the screen as possible. (Four big buttons: On time/5mins late/10mins late/Lecture cancelled ought to cover it). SteveBaker (talk) 02:25, 30 July 2015 (UTC)

More general suggestions

( I don't know, but I advise discussing the situation with your new superiors, dept. chair, etc. When I've been a lecturer, being more than 10 minutes late to class more than once or twice a semester would be grounds for dismissal. The way you write your example, you're actually running at least 15 minutes late for a 90 minute course, and many institutions would consider that inexcusable outside of rare emergency circumstances. Most universities will not consider traffic to be an emergency circumstance. The university may or may not have explicit policies on this. Some universities explicitly say the students are allowed to leave after 10 minutes of no instructor. Maybe the simplest thing to do is allot 2 hours for the drive. Sorry to give a non-answer but no amount of tech will save your job if you are consistently late to scheduled class meetings. ) SemanticMantis (talk) 17:18, 29 July 2015 (UTC)

I agree and understand. We have discussed this - which was a reason I was very reluctant to agree to take the class. We discussed doing it remotely and moving the time. There are no good solutions to the problem. Having me race from one city to another, past two large factories during shift change, in a car that will likely not survive the semester, is the best solution they could find. Last year, they simply canceled the course, which happens to be a required course for the program. 209.149.113.45 (talk) 17:41, 29 July 2015 (UTC)

Suggestion: Have an activity at the beginning of the class that doesn't actually require your presence. A written quiz is one idea. I'd make it not graded, just so they can gauge their progress, and you would have to rely on an assistant (pick a student) to deliver it on days when you are late (give them copies the previous session), if there's no place you can leave it, that's accessible to the students. It can have answers on the back, and you can then answer questions about it when you arrive. You can also write on the quiz "feel free to ask other students for help, if you need it".

I'd also explain the situation to the students in advance, so it's not a surprise to them when you are late. And have alternate routes planned out and listen to traffic advisories, so you have the best chance of bypassing any traffic problems. Also monitor construction zones. StuRat (talk) 17:50, 29 July 2015 (UTC)

I actually do little quizzes at the beginning of every class - it replaces the concept of taking roll. If you did the quiz, you were there. My fear is that the traffic is simply going to be hellish. As mentioned before, I have to drive past two factories during shift change. So, no matter what path I choose, I have to deal with a thousand people leaving and a thousand people arriving all at the same time - twice. Also, they just started major development projects at the start and end point. So, no way to get around either one since I start in the middle of one and end in the middle of the other. All around, this semester is going to be terrible. I'd be forceful with my "no" if I didn't really need the money. 209.149.113.45 (talk) 18:30, 29 July 2015 (UTC)

The satellite navigation app Waze can let you share your drive with your friends who use the app. This shows your approximate position and ETA to them. I'm not sure if it would be possible to rig up something to let anyone in your class see this (short of adding them all as freinds on the app), but it might be a potential solution. (It will also route you along the best route it can find, given it's traffic reports, which tend to be fairly good). MChesterMC (talk) 08:42, 30 July 2015 (UTC)

I'm curious about how accurate and current traffic reports get loaded into it. Let's say a TV news reporter in a helicopter says "it looks like there's an accident in the right lane, the right lane is blocked. Traffic is proceeding slowly in the center lane, but moving at near normal speed in the left lane. Police are on the scene, but no tow truck is present." How does this app get that info in a usable form ? StuRat (talk) 17:45, 30 July 2015 (UTC)

Most of those apps are driver-based. Drivers see an accident and then rush to grab their phone, start the app, and report it (and then create another accident). 209.149.113.45 (talk) 12:45, 31 July 2015 (UTC)

I can't comment on any of the mentions apps but for Google in NZ, while they connect to a few sources of road closures etc primarily from the government, and may also rely on user reports, AFAIK their most useful info probably comes not from intentional reports but simple data sharing. Given the relative popularity of Android phones and people using Google Maps or otherwise choosing to share their data with Google and with a data service and GPS on, they can see when major roads appear to be slow based on current travelling patterns. Nil Einne (talk) 22:59, 31 July 2015 (UTC)

I like Glympse. My friends and relatives can see me moving, stopping, resuming. I use their Email address when they are home, SMS when they're out, or both. I can send it to one or two or ten, whatever. Since it isn't part of some other navigation or social network, they don't need to install the app. They don't need to know there is such an app. The message just appears, and says to tap or click to see the Web map of where I am. Yes, they do need Web, which most cellphones have nowadays. The author seems to assume it's so simple, it needs no documentation. This is correct. Jim.henderson (talk) 18:12, 31 July 2015 (UTC)

Networking switch query

I have 2 computers connected to powerline ethernet adapters, and a 3rd connecting to my router. This can be a little slow sometimes (at least for game streaming and stuff). To speed things up would I be able to connect the 2 PCs via a switch, and then route that switch to the router via a powerline adapter? If I send traffic from 1 PC to another does the traffic have to go all the way to my router then back (presumably what is happening now), or will it go via the switch, which should be much much faster, as both PCs have Gigabit ethernet? 81.138.15.171 (talk) 15:42, 29 July 2015 (UTC)

What I would first do is get a crossover cable (very cheap) and plug both computers into one another. You will need to hard-set the IP of each one to something like 192.168.0.1 and 192.168.0.2. Then, you will have the absolute maximum speed of data transfer between the two computers. If there is lag, it isn't the network. Next, if you think you can make your network better, a hub will do. Two computers on a switch is a bit of a waste - especially when you are combining both signals into one upstream. 209.149.113.45 (talk) 16:07, 29 July 2015 (UTC)

How to do a dual boot of Windows 8 and 10: no USB drive or DVD?

I have already created the hard-drive partition.

Currently running Windows 8.1, with a 1 TB laptop. —24.228.117.156 (talk) 16:30, 29 July 2015 (UTC)

There's not a single USB port on there? What input options are there? Ian.thomson (talk) 16:41, 29 July 2015 (UTC)

Considering that upgrading from Windows 8.1 to Windows 10 is done through windows update, using a USB drive or a DVD is most likely not necessary. —SGA314 I am not available on weekends (talk) 17:05, 29 July 2015 (UTC)

First you must create a botable image of the partition that contains Windows 8.1. Next, you must 'extract' that image onto the other partition. you will need a special program to do this. do a Google search for something like 'hard drive image creator' or 'bootable hard disk image creator.' when you find the right program, use it to create an image of your partition that contains 8.1. This file should be roughly the same size as the size of the windows 8.1 partition. You should store this file on a SEPARATE hard drive or if you have enough space, on the 8.1 partition. This will allow you to extract the image onto the other partition. It would be helpful if you gave the amount of space taken up on the 8.1 partition as well as the size of both partitions. —SGA314 I am not available on weekends (talk) 17:02, 29 July 2015 (UTC)

This is actually the exact same thing I am going to do as well except that I will use a separate hard drive instead of dual booting. —SGA314 I am not available on weekends (talk) 17:07, 29 July 2015 (UTC)

Not an answer, but I agree with your plan for a dual boot, noting that Windows 10 is for suckers. So, committing to Windows 10 now as your only O/S would be foolish. StuRat (talk) 17:40, 29 July 2015 (UTC)

I run alot of VST and audio production software on Windows 7. Thus it would be wise for me to make a copy of all me software and try and run it on Win 10. I am also not very confident in the upgrade process's ability to keep all my files intact. I was able to setup a dual boot nce with XP and Win 7 but I don't remember what software I used. —SGA314 I am not available on weekends (talk) 18:57, 29 July 2015 (UTC)

Downloading NTSB hearing video

Hello Wikipedia! I am trying to download the video of yesterday's National Transportation Safety Board meeting on the SpaceShipTwo crash last October. Their video archives are at http://ntsb.capitolconnection.org/ and I'm able to play it using the Flash Media player running in Iceweasel (rebranded Firefox) on Debian GNU/Linux, but I don't see how to download it. I installed the "Flash and Video Download 1.74" add-on, but while it seems to work on other sites such as YouTube where it lists the various formats and resolutions of video files available for download, it doesn't seem to recognize any videos to download at the NTSB video's page http://ntsb.capitolconnection.org/072815/ntsb_archive_flv.htm . Can you suggest a Linux friendly method for doing this? I am also open to Windows only methods, but would have to borrow a friend's computer.

PS Copyright is not an issue here as the recording of this board meeting is a work of the US government. 2602:306:C4D5:C340:C8FB:D7A2:D78C:2586 (talk) 18:38, 29 July 2015 (UTC)

The player used on that site is JWPlayer. This video shows a Firefox extension which, it says, will process web pages which host JWPlayer and will download the flash videos embedded in them. I've not personally tried the specific extension it recommends (I'm running too many already), so I can't personally vouch for it - but if you opt for this approach, I'd be interested to know of that method works for you. -- Finlay McWalterᚠTalk 19:11, 29 July 2015 (UTC)

note: I did try other flash download tools, which are often successful - youtube-dl and VideoDownloadHelper (a Firefox addon) and neither worked for this video. -- Finlay McWalterᚠTalk 19:13, 29 July 2015 (UTC)

Thank Finlay, but it (the "Flash Video Downloader" extension shown in the video you linked) doesn't seem to work on this NTSB video. The download arrow never turns blue but stays gray with a red x (even after the video starts playing), though it does work for the video on the http://jwplayer.com/ page which is using JWPlayer.

Any other suggestions welcome.

I am also trying the rtmpdump utility, but it isn't working yet, with:

$ rtmpdump  -r "rtmp://fms.0172.edgecastcdn.net/000172/flv/ntsb/ntsb082712a.flv" -o ntsb20150728.flv
RTMPDump v2.4
(c) 2010 Andrej Stepanchuk, Howard Chu, The Flvstreamer Team; license: GPL
Connecting ...
WARNING: HandShake: client signature does not match!
INFO: Connected...
ERROR: rtmp server sent error
ERROR: rtmp server requested close
$

I got the URL by looking inside the source of the video's page, but I think that it may need more command line options, and I'm still trying to figure out how to run rtmpsuck. 2602:306:C4D5:C340:2DE3:2DBF:6157:E5DD (talk) 20:02, 29 July 2015 (UTC)

Well, the issue is still not resolved, but someone else must have managed to download it and put it up on YouTube: https://www.youtube.com/watch?v=QnMIfY_Wbrc .

So while I no longer have an immediate need, I'd still appreciate any pointers if someone here knows how to download from the NTSB site. Thanks! 2602:306:C4D5:C340:2DE3:2DBF:6157:E5DD (talk) 18:08, 30 July 2015 (UTC)

Windows update on Windows 10

Where is Windows update on Windows 10? It is no longer in the control panel and if I try to go to it from IE, it says that it can't find wuapp.exe. I want to make sure that it doesn't reboot without me telling it to. Bubba73 ^{You talkin' to me?} 21:02, 29 July 2015 (UTC)

Does this article address your question? http://www.cnet.com/how-to/windows-10-lets-you-schedule-windows-update-restarts/ 2602:306:C4D5:C340:2DE3:2DBF:6157:E5DD (talk) 21:12, 29 July 2015 (UTC)

That is what I'm talking about, but it says to open "settings". Where is "settings" on Windows 10 desktop? Bubba73 ^{You talkin' to me?} 21:21, 29 July 2015 (UTC)

OK, I found settings. Bubba73 ^{You talkin' to me?} 21:31, 29 July 2015 (UTC)

What do you think of the options it gives? I understand that W 10 keeps updates on automatic. Are the update restart options rich enough? 2602:306:C4D5:C340:2DE3:2DBF:6157:E5DD (talk) 23:14, 29 July 2015 (UTC)

The options seem to be more limited. I don't really want to schedule a reboot because sometimes I'm running something that is going to take a long time and a reboot will lose all of the work up to that point. Bubba73 ^{You talkin' to me?} 23:27, 29 July 2015 (UTC)

Running a PC with one single application (or not much more than that)

If I wanted to run just one single application like Vi/m or emacs on a PC (an x86) what else would I need? Would I need an OS at all or can I compile it to run without one? Could a PC be run without OS like an embedded computer can?--Yppieyei (talk) 21:10, 29 July 2015 (UTC)

You would need a kernel and whatever libraries the program needs, at which point you now have an operating system. "Operating system" is really a vague concept. It's more of a marketing term than a well-defined technical term. Now, to clarify, you could sit down and start adding code to vim to do all the things that a kernel and libraries do, but then you will just have written your own little embedded operating system that's only designed to run vim. A lot of embedded systems run operating systems. The only computers that don't have operating systems are really basic chips that you find in things like the proverbial elevator controllers and toasters. --108.38.204.15 (talk) 23:30, 29 July 2015 (UTC)

You can certainly work without an OS. That's actually how Linus Torvalds started writing Linux - he wanted a 'dumb terminal' program that could run on his PC with a modem without having to boot up DOS first...features were gradually added to it until it kinda accidentally became close enough to an operating system to actually become one! (For some reason, our articles on Linux and Linus don't discuss this very formative stage - but it's described in Linus' autobiography "Just for Fun").

I've also used PC's in things like Disney rides where we got rid of the OS entirely and ran our code on the bare metal. You don't necessarily need either a kernel or libraries or even device drivers - it's perfectly possible to write code that directly reads device registers and such...it's really no different when you're using something like an Arduino (which has no OS) or a PC. The biggest issue with running stand-alone programs on a PC is getting them loaded into memory in the first place. In my work, we replaced the BIOS ROM with our own EPROM chip...but it's been a while since that trick became impossible.

For something like Vim, which is probably single-threaded - only has to write to the screen and to save files to a disk drive - and only reads from the keyboard and loads files from the disk drive - that might not be too difficult. But if you wanted Vim to be able to read and write files on the disk drive that also needs to be used by (say) Windows - then you'd have to add a ton of code to handle how directories are formatted, where to find free space on the disk and mark that it's been used or freed. The code to do that might easily get bigger than Vim itself! Writing to the screen might not be difficult if you used your awesomely powerful graphics card to run in very-mundane VGA mode - but if you wanted a nice high-res screen with full color, you'd need some insanely complicated emulation of (say) an nVidia card's device driver - which would probably be impossible to write because those cards aren't documented to the degree that would allow that - and which would need a total re-write to run on an Intel graphics chip.

What tends to happen when you do this is that your stand-alone program tends to absorb more and more of the functions of an operating system (like handling files and directories on a hard drive - loading proprietary device drivers, handling interrupts, creating threads - dealing with memory management, etc) - until...just like Linus' dumb terminal program...you have actually written most of an entire operating system yourself.

Incidentally, when Linus needed disk operations for his growing dumb terminal project, he use the code from the pre-existing 'Minix' operating system - and thereby avoided the need to write his own until the project was already quite clearly an operating system in it's own right.

But for VERY simple situations, particularly if your I/O needs are very simple - you can indeed write programs without an operating system quite easily. Debugging them tends to be a bit of a challenge though - when you're running on the bare metal, you have no debugger to help you out - and even getting a "printf" to work might be a major problem!

SteveBaker (talk) 00:05, 30 July 2015 (UTC)

One interesting alternative is Tiny Core Linux. With Tiny core you just get the Linux kernel, BusyBox and (optionally if you want to run a GUI, FLTK). 9MB without a GUI, 15MB with. Add your application and you are done. --Guy Macon (talk) 00:18, 30 July 2015 (UTC)

If all you want is ultra lightweight cheapness - buy a "Pogoplug" for around $7 [2]. It's sold as a network backup box - but you can install Linux on it. With a USB port, ethernet and SD card slot and nothing else, it'll happily run Vim...if you have a way to SSH into it because it has no way to hook up a display.

This comes down to why our OP wants to do this. The cost of hardware that'll run an actual OS has fallen to essentially zero...so NOT running an OS has to be done for a reason. I can think of lots of reasons - security, for example. The less software that you didn't personally write, the easier it is to be secure. Maybe you want to be able to write poetry on your toaster - in which case Vim might be needed. But a $7 Linux box is hard to beat. The best advice here would come from understanding the true nature of the problem.

SteveBaker (talk) 02:41, 30 July 2015 (UTC)

Historical CPUs were much simpler than today's systems, too. It might have been possible to write code to the bare metal of an Intel 8051 or even an actual Intel 80386. Today, even trying to boot the CPU on a modern Intel Core Architecture programmable computer requires profound familiarity with a seven hundred page manual. A lot has changed: simple architectures gave way to complex systems tuned for higher performance. Even your main memory on a modern computer - say, one that uses DDR4 SDRAM - needs a software driver to initialize and calibrate it! Heck, even to retrieve a word of data from SDRAM is complicated: you need an elaborate control command sequence. Unlike SRAM, you can't just push an address into a register and read back data! You literally need to write an algorithm to retrieve a byte from an address. This is the sort of work that you don't even realize your operating system is doing for you. The hardware designs have evolved so that their feature-sets are well-matched to sophisticated operating systems, not to make life easy for bare-metal assembly code writers.

In the absence of an operating system, you cannot take advantage of such modern hardware. The job of the operating system is to relieve programmer pressure. You don't have to engage in the gritty details of the hardware in order to use it. You could pursue ancient computing machinery with simpler hardware interfaces, but you have to go back a long way to find machines that are architecturally "simple." Nimur (talk) 13:26, 30 July 2015 (UTC)

There are boot disks (or USB drives) that will boot up a PC and run a single program. They use some operating system, but don't have all the overhead of running full Windows, for example. They seem to avoid the periodic pausing that Windows seems to do when it checks for updates or whatever the heck it's doing. For example, if the program doesn't require Internet access, it can skip connecting to the Internet. One application is utility programs, like a disk reformat program, since you really don't want to reformat a disk while it's being written to. StuRat (talk) 13:45, 30 July 2015 (UTC)

Add User in Windows 8

How do I add a user account using Windows 8 on a laptop? I know how to get to the Control Panel to add a user in Windows 7, but I can't seem to navigate to a user accounts interface in Windows 8. Robert McClenon (talk) 22:11, 29 July 2015 (UTC)

Is what you are looking for under "PC Settings > Accounts"? I reached PC settings by just hitting the windows key and typing PC. Vespine (talk) 06:51, 30 July 2015 (UTC)

July 30

What language uses if!, enter!, exit!? II

This question reformulates my previous question with the same name above. I was quoting from memory, now I checked more details. There is a sample of code below.

I saw it in a French documentary about high-frequency trading on the stock market.

In what language is the code below written?

   Effectively buy
   IF Entry! >=0 THEN
       IF Entry! >0 THEN Prof! - (Curr! - A
   BS (Entry!))
       Entry! = Curr!
       Ext! = Curr!
   END IF

(...)

   LOOP
   CLOSE #1

(...)

   NEXT x!
   NEXT w!

Maxim! = -100 (...)

--Bickeyboard (talk) 11:26, 30 July 2015 (UTC)

This is BASIC Asmrulz (talk) 12:46, 30 July 2015 (UTC)

Specifically QBasic, judging by the compound IF, DO..LOOP and file descriptors Asmrulz (talk) 13:14, 30 July 2015 (UTC)

Even more specifically, the exclamation marks are type declaration characters, indicating that the variables are single-precision floats. Other such characters are # for double-precision floats, % for 16-bit integers, and & for 32-bit integers. Tevildo (talk) 16:01, 30 July 2015 (UTC)

Convert a PDF file to Microsoft Word

I have a PDF file. Is there any way to convert a PDF file to a Microsoft Word document? Thanks. Joseph A. Spadaro (talk) 18:15, 30 July 2015 (UTC)

That market is flooded. See lmgtfy.com/?q=convert+pdf+to+word 209.149.113.45 (talk) 18:40, 30 July 2015 (UTC)

Thanks, but those seem to do the opposite. Namely, take a Word document and convert it to a PDF format. I can already do that in Word itself (under "Save As" or "Export", I forget which). I am looking for the other way around: starting out with a PDF file and converting it into a Word file. Thanks. Joseph A. Spadaro (talk) 22:16, 30 July 2015 (UTC)

I do not understand how to think that way. For example, the third hit on the list for me is https://www.freepdfconvert.com/pdf-word which, if you go to the website, asks you to upload a PDF file and it returns a word file. The same with the other links https://www.pdftoword.com/ http://www.pdfonline.com/pdf-to-word-converter/ https://docs.zone/pdf-to-word ... as I said, it is a flooded market. 209.149.113.45 (talk) 12:48, 31 July 2015 (UTC)

For simple text copy-and-paste should work. For the general solution I would guess that there is a fundamental problem: The pdf might use a font that is not available on your computer, even if the structure of the document is converted correctly, line and page breaks will be off. 109.155.73.150 (talk) 00:07, 31 July 2015 (UTC)

You can "copy-and-paste" from a PDF file? You're kidding. I never knew that! Joseph A. Spadaro (talk) 02:59, 31 July 2015 (UTC)

No, I just tried that. And that is not what I mean. When I did a "copy-and-paste" from the PDF into a Word document, that simply "took a picture" of the PDF page and copied it onto the Word page. I want the actual text from the PDF (not just an image of the text), so that I can go in and change some words, add words, remove words, fix typos, etc. Can this be done? Thanks. Joseph A. Spadaro (talk) 03:03, 31 July 2015 (UTC)

You can copy and paste text from many PDF files. If you got an image when you did that, it's probably because the PDF only contains images (of text). You will have to use an OCR program to extract the text from the images, or transcribe them by hand. -- BenRG (talk) 03:49, 31 July 2015 (UTC)

It totally depends on how the PDF file was published. You can publish PDF files to be completely readable / copyable, or you can "lock them down" to the point where all you can do is take a screenshot. Vespine (talk) 04:17, 31 July 2015 (UTC)

AFAIK, there's no way you can lock down a PDF such that most PDF readers, including Adobe Reader, will take an image when you attempt to copy, at least in Windows. You can disable copying of the PDF, but AFAIK, in most readers that will mean you just can't copy from the PDF reader. On Windows if the program doesn't support copying and you try to, nothing will happen. Perhaps on other OSes this will take a screenshot instead, but not on Windows. You can of course use the built in OS screenshot functionality whether via shortcuts (Printscr etc) or an external tool, but it doesn't sound like the OP did that. So if they're copying and getting an image, this probably means the PDF is an image. Nil Einne (talk) 22:51, 31 July 2015 (UTC)

BTW, I should mentioned that these locks only work on readers which respect them. As with Word files or any similar popular and openly specced file types, provided the file can be opened, the locks aren't very effective. It's easily possible to not only find a reader which will ignore them, but to remove them. In certain countries, carrying out such countries may or may not violate laws such as the DMCA in the US, but the locks themselves don't do much. Nil Einne (talk) 17:50, 1 August 2015 (UTC)

This may be just an Acrobat Pro feature, but I am able to Save As -> Microsoft Word -> Word Document. Justin15w (talk) 16:28, 31 July 2015 (UTC)

That sounds perfect. I assume that Acrobat Pro is a product to purchase? And not free, like regular Adobe Acrobat. Correct? Joseph A. Spadaro (talk) 18:09, 31 July 2015 (UTC)

Why do you want to convert it to Microsoft Word? If you want to edit in Microsoft Word, then Word has had the ability to convert PDFs since the 2013 version [3]. However as with all other tools including Acrobat Pro, this won't work if your PDF is just an image. You will need to OCR it first. Nil Einne (talk) 22:45, 31 July 2015 (UTC)

@Nil Einne: Wow, I am getting so confused with the above conversation. Mostly, because I am not at all familiar with PDF files and all their technical abilities. All I know how to do is open up a PDF and read it with Adobe Acrobat. So, back to your question about "Why do you want to convert it to Microsoft Word?". So, this is the situation. A friend gave me a document that I like and want to use. It is a PDF document. I don't like it 100%, so I would go in there and make a few changes: add words, remove words, fix spelling errors, etc. That is why I wanted to change it from PDF to Word. What's the best way to do what I am trying to do? (I have Word 2013.) Thanks. Joseph A. Spadaro (talk) 04:16, 1 August 2015 (UTC)

Hi. Word 2013 introduced the ability to open PDFs. You can then save it as a Word document. This video shows how to do it. LibreOffice Writer (a free product), version 4.0 or higher, also has the ability to open PDFs. However, keep in mind that the import process is not perfect and the Word document will not look identical to the PDF, so you may have to touch it up a bit after opening it.

As for the technical discussion, Nil Einne was referring to the difference between text and pictures. PDFs can hold text, pictures, or both. In this case, the PDF can contain text, or it can itself be a picture of a page of text — just as if you pointed a camera at a page and took a picture of it. Now, if it's a picture of text, you would never be able to delete text, correct typos, etc. without some additional work that we haven't covered yet. But if it's text, you should be fine. I would just try and open it in your copy of Word and let us know how it goes.—Best Dog Ever (talk) 04:57, 1 August 2015 (UTC)

Thanks. Yes, I watched that video. I tried it with several PDF files. Some were PDF files of text. I was able to bring those into Word, and I was able to edit the text. That's exactly what I was looking to do. Some of the PDF files, however, were images (of text). So, when I transferred those into Word, I was not able to edit the text (since, technically, there was no text to begin with, rather just an image of some text). So, in the latter case, what – if anything – can be done? Thanks. Joseph A. Spadaro (talk) 04:17, 2 August 2015 (UTC)

The process of converting images of text to editable text is called optical character recognition (OCR). There are many programs out there that can perform OCR on a PDF. ABBYY FineReader is one. Adobe Acrobat Professional is another. Both are offered as free trials and they're both easy to use. However, OCR is essentially guesswork on the part of the OCR program. You may find some words are mis-spelled (or left out entirely) by the program and that the formatting may be incorrect. The quality of the output will depend on the resolution and quality of the image of the page.—Best Dog Ever (talk) 05:16, 2 August 2015 (UTC)

How to create "fillable" forms

Sometimes, I use "fillable" forms. These are forms that have most of the information already printed on them, but then I go in and "fill" various blanks (such as name, address, etc.). How does one create such a fillable form? Is there a way to do so, in Microsoft Word? Thanks. Joseph A. Spadaro (talk) 18:17, 30 July 2015 (UTC)

Specific instructions depend heavily on the version of Word you are using. In general, see the instructions. 209.149.113.45 (talk) 18:41, 30 July 2015 (UTC)

Thanks. I am using Microsoft Word 2013. Is the link above the applicable one? Thanks. Joseph A. Spadaro (talk) 20:09, 30 July 2015 (UTC)

Did you click on the link? 209.149.113.45 (talk) 12:49, 31 July 2015 (UTC)

Thanks. Yes. It seemed quite long and complicated. I wasn't expecting such a long and drawn-out process. I thought it would be maybe 2 or 3 quick steps. (Since I know nothing at all about creating a fillable document.) So, I was not going to go through that entire process if it did not work for my particular version of Word. Thanks. Joseph A. Spadaro (talk) 18:11, 31 July 2015 (UTC)

Cursing the Cursor

On my laptop running Windows 7, when the pointer stays over a control field for too long the field is "activated" as if I left-clicked it. This to me is a major nuisance, opening unwanted windows, etc.

There must be a way to disable this but I can't find it. Please help.

The pointer is moved around the screen by a touch-pad below the keyboard. I know where the touch-pad settings are located but they do not seem to govern what happens if the pointer is left too long in one place. Thank you, CBHA (talk) 20:23, 30 July 2015 (UTC)

I don't have a Windows system handy but I think this might be controlled by some handicapped assistance settings. Try looking for that while you wait for a better answer maybe. Dismas|^(talk) 21:07, 30 July 2015 (UTC)

Agreed. That's called "hovering", so I'd look for that term. StuRat (talk) 21:41, 31 July 2015 (UTC)

Thank you. I found a program group called "Ease of Access" which seems to be relevant to the problem. I'll have to experiment. CBHA (talk) 02:11, 31 July 2015 (UTC)

July 31

Updating to Windows 10

I have four computers in my office and I reserved the Windows 10 upgrade on all of them. I upgraded two of them yesterday and one more today. On the fourth one, until recently, it said that Windows 10 was reserved and it would let me know when I could update. But starting an hour or two ago, the Windows 10 stuff is gone and checking for updates doesn't show anything. What happened? Bubba73 ^{You talkin' to me?} 01:53, 31 July 2015 (UTC)

You got and W10 ISO image? If any trouble was on the system, backup all data, and perform a clean install from the DVD, means all data is wiped from the computer until backup is restored. I recommend to do so, I never made good experience when upgrading an existing system of any operating system. --Hans Haase (有问题吗) 11:15, 31 July 2015 (UTC)

You can "manually" upgrade to Win10 or create an ISO using the tool on this site: http://www.microsoft.com/en-us/software-download/windows10. Justin15w (talk) 16:23, 31 July 2015 (UTC)

Two Questions About Windows 10 Upgrade

• 1. Is it true that the upgrade is only free for one year? After which, what happens?
• 2. I tried to upgrade, but before the upgrade was complete, my computer was unable to connect to the internet - I am thinking of compatibility issues with the wi-fi driver - so I had to perform a system restore. If I decide not to continue with Windows 10 after the first year is up, can I roll-back?

KägeTorä - (^影_虎) (もしもし！) 11:30, 31 July 2015 (UTC)

1. The upgrade is available for a year - i.e. if you upgrade now, you keep it forever (though it's bound to the device - if you get a new computer, you'll need a new copy). If you reserve your upgrade now, but don't actually upgrade by 29 July 2016, you would have to pay for a copy of Windows 10. See the footnote on this page [4] MChesterMC (talk) 14:25, 31 July 2015 (UTC)

2. According to this BBC article, there's a rollback option available for 30 days after install (final line of the article). MChesterMC (talk) 14:53, 31 July 2015 (UTC)

A few questions about accessing audio streams and sending data to a USB port with python

Hello everyone. I have recently gotten a hold of a Raspberry Pi 2. I got it for a project that I am about to embark on. The project is simple; put this credit card sized computer into my electric guitar to run VST effects on my guitar's sound and output the result to the jack. The logistics behind this are quite complicated. The first thing i need to know is how to retrieve the PCM data from the DIN pin on the Pi's GPIO connectors. As a note, any code I will be writing I hope to only use python. If I absolutely have to, I will do some C++. My next question is how would I send data to a USB port on the Pi? I ask this because I am going to setup a feature that will allow me to plugin a USB chord from the Pi to my Windows PC to record the sound. I am completely new to Linux and have used windows pretty much my whole life. I have many more questions but this is just a start. Thanks for your help in advance. —SGA314 I am not available on weekends (talk) 15:41, 31 July 2015 (UTC)

Audio effects processing of this nature requires low latency. In plain english: every instant that the sound is delayed because of your input electronics, software, and output electronics, will cause annoying audible effects (similar to reverberation). This is not usually desired (at least, not for most guitar effects - a handful of effects intentionally use reverb or delay).

The short of it is that python is rarely a good choice for real-time hardware I/O. Python's runtime requires a buffer; the OS runtime requires a buffer; the audio device driver requires a buffer; the audio input hardware requires a buffer. Your processing may be nearly instantaneous; but the output must be buffered in Python, and again at the operating system runtime, and the device driver, and the hardware ... and before you know it, you've got 200 milliseconds of audible delay without even considering how long your effects processing calculations actually require.

Here's a website with details to set up low latency audio on a Pi. If you aren't already familiar with JACK on Linux, you'll want to brush up on that, too. Here is the introductory documentation. Nimur (talk) 16:03, 31 July 2015 (UTC)

I will be sure to take a look at those 2 very useful links. Ok so python no go. I know all about latency(this is why I love ASIO) and I messed with Jack a little bit yesterday. I take it that I will have to use some C++ or C, right? Because in the end, I am going to send the audio to a USB port on the Pi to be outputted to my Windows PC(Yes I know this I will have to write a driver to make it show up in the list of connect audio devices). For my next question, I will ask, how would I use Jack to access the audio coming from the DIN GPIO pin on the Pi? And would there be any way that I could send an analog signal to that pin and convert it to digital on the software level? This would eliminate the need for me to use an external Analog-to-Digital converter. —SGA314 I am not available on weekends (talk) 16:14, 31 July 2015 (UTC)

Where do you get this thing about quadruple buffering? There's no reason you can't get direct access to the audio hardware's buffers from Python. -- BenRG (talk) 16:50, 31 July 2015 (UTC)

Well how would you do that? —SGA314 I am not available on weekends (talk) 16:56, 31 July 2015 (UTC)

(edit conflict - same question, with fancier language):

Using which Python API may one access or control the Raspberry Pi audio hardware? Are you aware of any such method? If we remit ourselves from real software that does exist, and venture into the realm of theoretical programming, then of course the hardware can be controlled directly from python... or Lisp or Forth. In fact, one could run python on bare metal without an operating system, and a purist could access I/O using only native python code! But these implementations do not exist today, and creating an implementation in that fashion is not an accessible task for programmers with finite time. Nimur (talk) 17:00, 31 July 2015 (UTC)

I've never programmed for the Raspberry Pi, but buffering and Python have nothing to do with one another. Whatever you plan to do in C, you can do in Python with ctypes. The idea that Python requires a buffer, and the OS and audio drivers require their own buffers (but apparently only when you're using Python, not when you're using C), is something that you made up. There's no reality to it. -- BenRG (talk) 17:49, 31 July 2015 (UTC)

BenRG, direct access to audio hardware I/O in Linux occurs inside the kernel. (Here's the Raspberry Pi implementation for kernel-4.2). If you wish to bypass these software buffers, you must not use user-space APIs; you must not use ALSA kernel modules; you must directly write to the hardware. Are you seriously suggesting that python modules can be compiled and linked into a Linux kernel - and furthermore, that this task is accessible to a novice programmer?

If you can live with a little latency, and want to stay in user-space, you can write code to jack; you could, in principle, do that in python or any other user-space programming infrastructure. If you use existing code, like py-jack, you relinquish control of scheduling (it creates a thread for you) and you relinquish control of buffering (the API does dumb software copies of every buffer). If you write your own code - in any language - the best you can ever do is "as good as jack in user space."

On a Raspberry Pi, at about 700 MHz, this is probably not good enough for a real-time audio effects processor. When you care about audio I/O, latency means everything (and FLOPs are not very important - "you'll always have enough" for human-audible sample rates). You would probably do better on a processor a thousand times slower than a Pi, if it provides the programmer direct hardware access. I've had great success with Renesas development boards. They're cheap, they're easy, their on-chip analog-inputs are versatile and perform well above the requirements for reasonable audio signal processing; and the CPUs are so simple that you don't need an operating system. You can actually manage your I/O in real-time. (... and for completeness: the last I checked, nobody had ever ported Python to an M16C CPU; it could be done, but you'd probably need more memory).

Nimur (talk) 19:36, 31 July 2015 (UTC)

No, No, No. I am using A Raspberry Pi 2. It runs at 900Mhz and has 4 cores. I have overclocked mine to 1Ghz. And I don't want to do conventional DSP. I want to run VST effects. Not do normal DSP.—SGA314 I am not available on weekends (talk) 19:48, 31 July 2015 (UTC)

You may do that. You will probably find that any solution you produce using this technology stack suffers from significant latency. This will make your effect "sound late" as you play your musical instrument. Nimur (talk) 21:01, 31 July 2015 (UTC)

I have found out that QEMU can run x86 windows programs on the Pi. However, I don't know if it can run a single program. Not an entire copy of windows. If I were to run a copy of windows on the pi, this would require at least 16gb of space. and I only have 18gb of space left on the sd card. Now this does not include the space that the VST software will take up(which is a few gigs). So obviously this option is not very workable. In the end I would like to get permission from all the authors of the Pi's software(and the windows software that I will be running) to sell a guitar that has a Raspberry Pi running my custom setup. If I had to run an entire copy of windows, it would be impossible for me to sell the Pi all setup and ready to go. Instead, I would have to give a tutorial on how to set it all up and the user would have to buy another copy of windows as well. This is why I need to figure out how to run just 1 program, just like WINE can do. As for latency issues, I am sure if I fiddle with QEMU and the latency compensation settings on the VST host, I can kill any delay that may result. Thank you for explaining the latency problem. I have run into this problem on my Windows PC before. I was able to defeat it messing with the latency compensation settings in ASIO4ALL's control panel(What I probably did was I just reset the ASIO drive and therefore fixed the latency issue). —SGA314 I am not available on weekends (talk) 17:54, 1 August 2015 (UTC)

So onto the next question. How would I send data to a USB port on the Pi. I would prefer to do this in python but because of latency issues, I don't think I will be able to do this in python. —SGA314 I am not available on weekends (talk) 17:14, 31 July 2015 (UTC)

Are you familiar with the USB device protocol? If you are not already profoundly familiar with these specifications, start at the USB Device Class documentation on the USB Developers webpage. Nimur (talk) 22:31, 31 July 2015 (UTC)

No I am not familiar with the USB device protocol, I will be sure to take a look at this, thank you. When It comes to accessing audio streams, sending data to USB devices, using QEMU, and using Linux in general I am a complete newbie. —SGA314 I am not available on weekends (talk) 17:54, 1 August 2015 (UTC)

After creating back-up disks, can I delete files on C drive?

I run an ASUS laptop with Windows 7. The computer did not come with installation disks. I was prompted to burn Windows restoral disks on 4 DVD's. At no point after the creation of the restoral disks was I prompted whether I wanted to delete those files (must be at least 12GB-16GB) from my hard drive. Can I free up that space? What files should I be looking for? I have googled this and searched windows help, but the kewy words are to vague to get a meaningful result. Thanks. μηδείς (talk) 19:12, 31 July 2015 (UTC)

The few laptops I've installed Linux on tend to have a partition on the drive that contains the installation software. I wipe that partition because it won't be used. If that is how your system is set up, you have to work with a partition manager to erase the partition and expand your main partition to use the space. 209.149.113.45 (talk) 19:30, 31 July 2015 (UTC)

You need to know what files have been stored in the backup. A backup is least a backup if it can be restored successful. Never trust a single backup. If you are out of disk space, use CCleaner or similar tool. --Hans Haase (有问题吗) 18:52, 1 August 2015 (UTC)

August 1

Email recursion

Can a mailing list be subscribed to itself? If yes, what would happen when a new message is posted? --Ricordisamoa 07:34, 1 August 2015 (UTC)

Hopefully the mailing list software would stop that, otherwise you may get a mail loop, with amplification each time around the loop so that everyone on the list gets thousands of copies of the same message. Graeme Bartlett (talk) 08:14, 1 August 2015 (UTC)

For example, GNU Mailman's documentation for how it prevents such "mail loops" is here. Modern listservs add a range of extra headers to emails as they forward them (per RFC 2369) and use them (and some clever filtering, which anticipates some of the more common stupid things that can happen) to handle loops, replies, and the dreaded "I am out of the office" reply. -- Finlay McWalterᚠTalk 17:56, 1 August 2015 (UTC)

BTDTGTTS: in the early 1990s I wrote a web-based bulletin board cum mailing list system that had the occasional mail storm, for example when an out-of-office message was malformed, which was pretty scary if it wasn't caught in good time, though I think it was at least sensible enough not to send emails to itself. AndrewWTaylor (talk) 20:22, 1 August 2015 (UTC)

What is inking?

In the custom install of Windows 10, in a couple of places it mentions "inking". What does that mean (I can't find it)? Bubba73 ^{You talkin' to me?} 14:42, 1 August 2015 (UTC)

"Inking" seems to be their word for the act of writing on a touchscreen with a finger or stylus - e.g. Presumably they say that and not "writing" to make it clear that they're not talking about writing-with-a-keyboard. They could have said "stroking". -- Finlay McWalterᚠTalk 15:09, 1 August 2015 (UTC)

Resolved

Even though there is no ink involved. Thanks. Bubba73 ^{You talkin' to me?} 15:35, 1 August 2015 (UTC)

I would have favoured "rubbing" as a nod to Isaac Asimov's portrayal of touch-screen technology (or possibly touchpads) in Foundation's Edge (1982) where the native Hamish peasants disparage the academic Second Foundationeers as effete 'pewter rubbers. {The poster formerly known as 87.81.230.195} 212.95.237.92 (talk) 13:46, 3 August 2015 (UTC)

Italic fonts in word processing

This question concerns italic fonts in word processing (for example, Microsoft Word). I had always assumed that the italicized letters were completely new and different letters created for each letter (A, B, C, etc.) in the particular font. In other words, the creator of the font "designs" (for lack of a better word) the letter "A" and "B" and so forth. Then, completely independently, he "designs" a new design for italics "A" and for italics "B" and so on. However, it just dawned on me today that perhaps that is not the case. My new theory is that they simply take the "regular font" and merely rotate it a few degrees clockwise. So, they don't really "design" a new letter, they just take the old design of the non-italicized letter and simply rotate it a few degrees clockwise. So, does anyone know anything about this? Do they "design" 52 completely new letters (26 each, upper- and lower-case) for the italicized alphabet that are separate and distinct from the 52 non-italicized letters? Or do they simply take the 52 non-italicized letters and rotate them around a few degrees clockwise? I hope this question makes sense. Thanks. Joseph A. Spadaro (talk) 20:05, 1 August 2015 (UTC)

Italic_type#Examples has examples of where the italic letter tends to vary in its basic design from the roman equivalent. I think these differences tend to be less marked in sans serif typefaces such as Helvetica, but in general the italic letters are designed separately, though with many of the typographical characteristics and "feel" of the roman. A "rotated" version would be Oblique type. AndrewWTaylor (talk) 20:17, 1 August 2015 (UTC)

Thanks. Somewhat totally unrelated question. Who would go to all the trouble and the bother to design a font? They don't receive any money (or payment) anywhere in the process, do they? I mean, fonts are simply "out there" and available free to everybody, no? Or is there some piece that I am missing? Joseph A. Spadaro (talk) 20:47, 1 August 2015 (UTC)

High-quality fonts certainly are sold for significant amounts of money. Microsoft commissioned the design of Arial to get around licensing Helvetica. Of course, Donald Knuth Metafont and the Computer Modern fonts opened up the field, and there are now quite a few good quality free fonts around, at least partially in the spirit of Free Software. --Stephan Schulz (talk) 21:09, 1 August 2015 (UTC)

Thanks. But, I am still missing the part where money/payment enters the picture. I have been using computers for 25-30 years. I always have hundreds of fonts in my Microsoft Word program. I have never once paid a dime for any font. When I purchase Microsoft Word, is part of that money paying for the fonts that are included in Word? I was told that Word itself does not have any fonts. But, rather, the fonts are stored in my computer (maybe in the operating system?) and that Word simply accesses those. When I purchase Windows, is part of that money paying for the fonts that are included in Windows? Joseph A. Spadaro (talk) 04:21, 2 August 2015 (UTC)

It depends. Some word processors did come with extra fonts as part of the deal. But yes, in modern OSes a lot of system fonts are included and paid for with the OS (or even with the computer, e.g. in the case of Apple). Modern OSes have central repositories for fonts, and may offer facilities to automatically replace fonts you don't have with ones you do have (as in the case of Arial/Helvetica). But take a look at e.g. http://www.webtype.com for what you can buy. --Stephan Schulz (talk) 07:38, 2 August 2015 (UTC)

So, just for clarification. When I pay $100 (or whatever) to purchase Windows, a part of that money is to pay for the fonts that Windows gives me. Correct? And the Microsoft people are paying somebody out there (whoever) for the rights to include their special font in the Windows package. Right? So, out of the (hypothetical) $100 that I pay Microsoft to purchase Windows, Microsoft pays $2 (hypothetical price) of that price to the creator of the "Century Gothic" font? Joseph A. Spadaro (talk) 20:31, 2 August 2015 (UTC)

Roughly. Some of the fonts will be free, and Microsoft has not licensed but created Arial, so they don't pay per sale for that font. I don't know what their arrangement with other font designers is - lump sum or volume pricing. --Stephan Schulz (talk)

Expressive power of computer languages: it's all about the syntax/logic?

When analyzing the theoretical expressive power of programming languages (not the verbosity of the programming languages or how concise programs are) are there further criteria besides the class of formal grammar in the Chomsky's hierarchy and the type of logic chosen (for example first/second/higher-order, type logic or whatever other logic formalism)?

Is there an analysis of expressive power of data structures? Are there other constrains that limit the expressiveness of a computer language?

It seems that all these formalisms deal only with how we combine ideas, but not how well we can express an idea using a programming language. For example, they don't enter into the question of the limitations of an imaginary programming language with only a binary and integer primitive type. — Preceding unsigned comment added by Denidi (talk • contribs) 21:01, 1 August 2015 (UTC)

But it's all about verbosity/conciseness/convenience/elegance. You can write almost any program in almost any language (aside from specially limited languages). Each language is "turing complete" and the church-turing thesis says that two things that are both turing complete have equivalent expressive power.

So the answer is that they are all precisely equal...if you ignore all the things you're telling us to ignore. SteveBaker (talk) 21:08, 1 August 2015 (UTC)

That means that Java and C, for example, have the same expressive power, although it might be easier to use one or the other depending on your program at hand. However, are there still things that can't be expressed neither in these two languages nor in any turing complete language?

Is there a formal language more expressive and beyond all these languages that we know? Or have we already reach the top, even if we could still develop programming languages that are more convenient or elegant for us humans to use?

Is the expressive power of a turing complete language even comparable to a natural human language? --Denidi (talk) 22:40, 1 August 2015 (UTC)

We could define a language with non-computable functions but then it is believed it would be theoretically impossible (and not merely practically impossible) to evaluate programs in the language. If we want it to be possible to actually evaluate our programs then all languages can do the same, except if they have constraints which make them unable to evaluate some of the computable functions. There are very simple languages like Turing machines (which are basically a computer language before that became a term) which can evaluate all computable functions. Note: One of the conditions for being able to evaluate all computable functions is being able to use arbitrarily much memory. When it comes to practical implemetations of languages like compilers and interpreters, they may fail on that detail. But who cares whether your program could theoretically handle a googolplex bytes if the universe had just been large enough to fit the memory chips? PrimeHunter (talk) 23:26, 1 August 2015 (UTC)

Anything a real 2015 computer can compute (using any computer programming language), a Turing machine can also compute.

Most computer programming languages, if we ignore memory resource limitations, are Turing-complete -- anything a Turing machine can compute, you can write a program that (when run on a computer with "enough" memory) can compute the same result.

There are many things (such as the halting problem and certain functions written in super-Turing programming languages) that cannot be computed by any Turing machine. Those things therefore cannot be computed by any program in any Turing-complete language on any real computer built before 2015.

Some people speculate that we will someday be able to build machines that solve at least some of those things -- super-Turing computation.

Other people speculate that anything that can be computed in our physical universe, can be computed by a Turing machine -- the Church–Turing thesis, Church–Turing–Deutsch principle, digital physics, etc. If that is true, this would imply that anything that human brains or anything else using natural languages (or both) can do, or anything that any computational machine we build can do, a Turing machine can (eventually) also do.

While we may be able to talk about things like oracle machines, and talk about machines that run super-Turing programming languages, if "digital physics" is true, such devices cannot actually be built in our universe.

It is still an open problem which of these two speculations will turn out to be true; one of a list of unsolved problems in physics. --DavidCary (talk) 04:11, 2 August 2015 (UTC)

While, I suppose, it's conceivable that a computer with more power than a turing machine could be made (I rather doubt it) - it has not yet been made. Even the simplest machine codes (eg SUBLEQ) are turing-complete - and even the most complex programming languages are able to be run on standard computers - which mean that they to are no more powerful than a turing machine. So it doesn't matter what might theoretically happen in some astounding future invention - right now, all programming languages are equal in power.

That said, there are huge differences. It's a heck of a lot easier to write almost anything in Java, C++, Python, PHP, JavaScript than it is to write in SUBLEQ machine code...but it's only a matter of convenience. SteveBaker (talk) 05:05, 2 August 2015 (UTC)

Cue INTERCAL. The standard way to show that language (or formalism) X is Turing-complete is to show that it can simulate language or formalism Y that already is Turing-complete. Since everything we do on existing computer in the end boils down to machine code (which a TM, or, more conveniently, a C simulator can simulate), nothing we can develop on such a computer can be more expressive than the Church-Turing class. --Stephan Schulz (talk) 07:45, 2 August 2015 (UTC)

August 2

Need help setting up an internet system in a very large house (20 bedrooms)

I've recently moved into a co-op, with 20 bedrooms and about 24 people living in it. Its two stories. The internet is abysmal. We have the most expensive internet comcast provides, which gives us a mb/s cap way higher than anything we ever see. We have a router/modem that comcast claims is top of the line and there's no reason to replace it. We have two other router/modems that are piggy-backing off of our actual source of internet. My financial manager said he is willing to pay for better internet, he just has no idea how to improve it. I need some advice on how to set up an internet system to provide decent internet to about 25 people. Any and all advice is very much appreciated. I also have a couple questions if your able to answer them please do:

Would it help if instead of paying for one very high cap source, we instead paid for two sources with a moderate cap?

Would it be better to have these router/modems connected to our source router, (they all have their own network names) or should we disconnect them and just hook up some of the wi-fi boosters that extend the range without creating new networks?

Would switching to a company other than comcast help? according to internetprovidersbyzip.com we have other options.

Should we be looking at business plans as opposed to residential?

2605:6000:EA01:7E00:A010:411B:F7AE:4C64 (talk) 04:05, 2 August 2015 (UTC)

You will need to know if your cap is exceeded or not. There is no point in boosting if you are not hitting it. It sounds as if you are using WiFi. If you can actually get a wired ethernet connect to each room that will prevent wireless congestion. But for so many rooms that will cost 1,000's of dollars. Wifi repeaters will probably just degrade the overall service, unless you can actually wire in each repeater point. For this number of people 10 megabits per second may be OK. Do you know what rate you are getting? Graeme Bartlett (talk) 11:32, 2 August 2015 (UTC)

Don't try to reinvent the wheel. This sounds like a good application for Setting up a Linux-based Open-Mesh Wireless Network. No consultancy or hidden fees and no vendor lock-in.--Aspro (talk) 14:36, 2 August 2015 (UTC)

What sort of building is a "co-op"? How many "data lines" are connected to it? The problem isn't with your "cap" it's with your bandwidth. It sounds like the building possibly needs a backbone, this is something like an "apartment block" would have to enable each apartment to have its own internet connection. For 25 people the building needs more than 1 connection, even with the fastest internet available where I live, 100Mbps, that means you'll only get about 8Mbps per person when only half the people are online, that's crap. In reality, without very good QoS which is hard to implement, it's likely that just one or a few people can consume all the bandwidth and everyone else gets almost nothing. You need to talk to comcast, or who ever manages the internet infrastructure. it might not be cheap, but then again if it means you'll be buying 3 or 4 internet connections instead of 1 they might be willing to do it. most apartment blocks are backboned by the internet provider for free because it means they'll get more business. it totally depends who manages the internet in your area, what kind of building it is, and probably several other factors. Vespine (talk) 23:22, 2 August 2015 (UTC)

It's true that speed will reduce according to how many people are on-line at the same time, but you can test whether this is the problem at a time when you are the only person using the connection. It sound to me as if the wireless connections are interfering with each other, or there is some other interference in the building. I'd suggest either Aspro's solution or DIY Cat6 (or higher) cabling to each room. Do you know what speed Comcast supplies? Vespine is very fortunate in having 100Mbps available. The best that British Telecom can manage here over six miles of copper is just one Mbps. It's just about usable, but not what I'd call proper broadband. Try some speed tests when you are the only user, using the wireless connection, then connecting direct to the primary router (did you say MODEM? Apparently these still exist in the USA. If so, then there is your problem!) If your supply relies on miles of copper, then there's little you can do about it. (I think Comcast normally supplies the service vis co-ax cable doesn't it? Does it use the same bandwidth for both TV and internet? Perhaps you should talk to Comcast - I know nothing about their service, except that nearly half of their customers have complaints.) The usage cap seems irrelevant here, it's speed that counts. Dbfirs 07:56, 3 August 2015 (UTC)

Is there anyway to remove the smiley face on Microsoft Visual Studio 2015?

Is there anyway to remove this smiley face thingy[5] in VS2015? It looks very out of place in a piece of professional software that cost thousands of dollars, plus it clashes with the otherwise coordinated white on grey color scheme. My other car is a cadr (talk) 17:39, 2 August 2015 (UTC)

Hey, guess what that smiley face button is? It's the "Send Feedback button"! You can click that button to directly share your thoughts with Visual Studio's developers... even if your thoughts are that their user-interface is distracting. The Visual Studio team call this type of bug-reports (i.e. bug reports and feedback specifically about the Visual Studio experience) "sending a smile" or "sending a frown."

You can customize the Visual Studio UI, including adding, removing, hiding, and modifying the default menus.

Nimur (talk) 01:46, 3 August 2015 (UTC)

I can find where to modify menus in the Customize dialog, but there's no option to modify non-menu items like the smiley face[6] (at least not one that I could find).My other car is a cadr (talk) 01:58, 3 August 2015 (UTC)

This thread may help. -- BenRG (talk) 08:54, 3 August 2015 (UTC)

Excellent! Thanks a lot. My other car is a cadr (talk) 13:15, 3 August 2015 (UTC)

Resolved