Welcome to the computing section
of the Wikipedia reference desk.

Select a section:

WP:RD/C

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.

October 25

refused to connect

A couple of web sites have given the message "refused to connect" when I attempted to access them. Why would this happen? Is there anything I can do about it? --Halcatalyst (talk) 15:08, 25 October 2018 (UTC)[reply]

Any example? Ruslik_Zero 20:28, 25 October 2018 (UTC)[reply]

One was to register for an AARP event ("aarp.cevent.com refused to connect" and the other I can't remember. --Halcatalyst (talk) 03:51, 26 October 2018 (UTC)[reply]

This link: https://aarp.cvent.com/events/EventRsvp.aspx works for me. Ruslik_Zero 20:44, 26 October 2018 (UTC)[reply]

Yes, that link works for me too. Above, I should have included the actual link where I get the error: https://aarp.cevent.com/FWOnTapDM . --Halcatalyst (talk) 03:57, 27 October 2018 (UTC)[reply]

Looks to be because the URL is invalid. cevent.com redirects to cvent.com. The website clearly brands itself as Cvent. I'm guessing they keep the cevent.com simply for typos etc but they may not have set up each subdomain to redirect correctly. Anyway if you typed in that cevent.com URL yourself, I suspect you simply screwed up. If it came as that from somewhere else printed or online, I guess someone else screwed up. The correct URL should be aarp.cvent.com not aarp.cevent.com

https://aarp.cvent.com/FWOnTapDM works fine although "The event you are currently requesting is not open for registration."

By the same token if I try to access https://support.gogle.com/ it doesn't work. If I try to access https://support.google.com/ it will work. If I try to access http://www.gogle.com/ it also works. If I try to access https://www.gogle.com/ it slightly of works. (They are using the security certificate from google.com so most browsers will complain that it's in invalid certificate. If you ignore this, Google probably won't understand what you're trying to access so you'll get a 404.) Interesting enough, https://gogle.co.nz/ works but goes to some sort of internet safety for kids programme page.

Nil Einne (talk) 06:16, 27 October 2018 (UTC)[reply]

November 6

Convert Borland Sprint file to Microsoft Word

Is there a way to convert a file from Sprint (word processor) to Microsoft Word? (I googled and didn't find a way.) Bubba73 ^{You talkin' to me?} 01:48, 6 November 2018 (UTC)[reply]

According to Corel, WordPerfect (WP) can import Sprint files. If you have access to a copy of WP, you could import it and save it as a Word or RTF file, or perhaps see if Word can read the WP format better than WP can save Word format.-gadfium 04:24, 6 November 2018 (UTC)[reply]

I used to use WordPerfect (years ago). I'll check into that, thanks. There is a 30-day free trial. I have one file in particular to convert, but I'll gather up all of my Sprint files, get the free trial and convert them to something else. Bubba73 ^{You talkin' to me?} 05:08, 6 November 2018 (UTC)[reply]

Resolved

I downloaded the trial version of Word Perfect. It read in the Sprint file just as it should and I saved it to a MS Word doc file. I read that file into MS Word, and it was just as it should be! Bubba73 ^{You talkin' to me?} 02:54, 8 November 2018 (UTC)[reply]

Cool!-gadfium 08:13, 8 November 2018 (UTC)[reply]

CSS-Only Solution for Forcing 480p on YouTube Without Diminishing Display Size

I am very interested in finding an elegant CSS-only solution for forcing SD 480p on YouTube without diminishing the video display size, to use with Stylish/Stylus on Mozilla Firefox (i.e., the display size should remain 1280x720, but the quality should be SD rather than HD) — GX, May 1971 (talk) 03:43, 6 November 2018 (UTC)[reply]

previously clicked-on Wikipedia hyperlinks eventually changing back to blue from purple

Hello,

Feel free to skip to the last paragraph if you just want the nuts and bolts of my question. I have tried to find a solution to this problem and have come up so short that I suspect it may not be possible to achieve my goal here, but since this is the only website I want this solution for, I'm hoping you guys might have an answer or some insight.

Over the past several years I have chosen to make a hobby out of thoroughly reading the Wikipedia articles for old movies, then renting and watching them after I've learned as much as possible about their interesting productions or their prominent actors. I do that by clicking on the personnel involved in the movie from the summary sidebar area and from the list of actors/actresses cast in the movie. I use Google Chrome for this, which is the web browser I use for most other things.

I know that I'm done reading about a movie when all of the blue hyperlinks in the article have been clicked on and made purple. It is aesthetically satisfying to scroll through a long article and see no blue links in it, and it's a portion of the overall enjoyment I get from the hobby.

The problem is that over the years I've watched a few hundred movies and thus clicked on a few thousand actors and other production personnel. I do not always remember who I've clicked on and will not always have remembered a minor character actor's details enough to avoid me reading their entire article over again if their name doesn't remain purple when they appear in other movies. My vague goal is that after a lot of movies have been watched that there won't be nearly as many blue hyperlinks in the pages for my next movies and thus I will save time on reading about them, a process which can take up a lot of my day.

Is there any setting I can change or feature that I can ensure is turned off (perhaps of my antivirus program) that would help me permanently retain my browsing history, especially as it pertains to Wikipedia hyperlinks? The only solution I've found is to periodically spend as much as two full days going through the movies I've already seen and re-clicking on their personnel to achieve the satisfying aesthetic and to hopefully save myself future time. It is especially frustrating when I take a long-ish break from this hobby as when I return the links are all blue again without me having made much progress on more movies watched.

Jordanmiller335 (talk) 17:38, 6 November 2018 (UTC)[reply]

I think Chrome keeps your browsing history for about three months. It will be less if you clear your browsing history, or have set it to automatically clear when you close your browser. To keep it indefinitely, the browser extension History Trends Unlimited may help. I have no experience of using this extension myself.-gadfium 05:13, 7 November 2018 (UTC)[reply]

To elaborate on the above reply...

First, a little bit of theory. The way visited links work is that your browser (which is in all likelihood one of Chrome, Firefox, Safari, Opera and Edge) retains a history of visited websites. When you visit a website, that website sends stylistic instructions to the browser as to how to display stuff, including how to differentiate page links depending on whether they have been visited. (Notice that the website does not know by that mechanism which pages you have visited; furthermore, the browser can disregard the website's instructions.) Most websites use a blue-ish color for standard links, but almost all use something purple for visited links (why? probably because users got used to it by now).

The most probable cause of purple links going blue in your case is the browser history being lost. Can you tell us which browser you use, and whether you have some weird settings on it? Tigraan^{Click here to contact me} 08:49, 7 November 2018 (UTC)[reply]

Per the original post, they're using Chrome. Since this is a WP-centred request, I'm wondering if there's some setting regarding pages on your watchlist that could be exploited? For example, if they added every read article to their watchlist, could that somehow be used to maintain the links in the browser history? Matt Deres (talk) 01:12, 8 November 2018 (UTC)[reply]

You guys are all right on point in understanding what my goal is; I was surprised and delighted by the link to the browsing history extension. Unfortunately in the notes for that extension it says that since it keeps its history separate from Chrome, it won't retain the color of clicked-on links. It would work for practically anything else in proximity to my issue, it seems.

I do indeed use Chrome, but I am very open to switching web browsers if any of the others are known to keep their history at least longer than the 3-ish months that Chrome keeps it for, and would even dedicate that browser solely to this hobby if it was an issue of my using it for secondary purposes flooding out the history kept for Wikipedia. I would also be willing to mark every article in my watchlist as was mentioned, if that seems like a solution. I haven't changed any notable settings in Chrome as I couldn't find any that would help this. I have noticed that my antivirus will sometimes clean my temporary internet files while the computer is idle and was unsure if that was a cause, but I turned that feature off. Jordanmiller335 (talk) 21:36, 8 November 2018 (UTC)[reply]

In Firefox you can go to [about:config] and set places.history.expiration.max_pages to a large value so that the history does not wrap. It would normally be about 100000 pages. However having a large history does use memory in your computer, so make sure you have heaps of RAM to hold it all. Graeme Bartlett (talk) 01:50, 12 November 2018 (UTC)[reply]

Thank you for the reply Graeme! The solution I found was that Internet Explorer & Microsoft Edge are both affected by the Internet Options control panel page, wherein I can set the maximum days that history is kept to as much as 999 days from their default 20 days. I just tried your remedy in Firefox and it would let me go to modify the value but when I would save the value it reverted back to what it had always been, even after re-launching the web browser. I am satisfied with dedicating the Edge browser to this hobby. Thanks again! Jordanmiller335 (talk) 15:55, 12 November 2018 (UTC)[reply]

November 7

Intel Xeon versus i7

Comparing a single core, how would the performance of a 3.4GHz Intel Sandy Bridge i7 compare to a 2.4GHz Xeon E5-2695v2 ? This would be on integer operations only, often with a lot of reading and writing to memory. The i7 has a higher clock speed but the Xeon is a newer design with more memory cache. Bubba73 ^{You talkin' to me?} 05:29, 7 November 2018 (UTC)[reply]

This can't really be answered without more information. Critical information would be: (1) the exact ratio between arithmetic operations (internal to the CPU) and memory accesses, (2) whether both systems have the same L2 cache size and design, (3) how the size of the working set of the program compares to that of the L1 and L2 caches, (4) if the working set is larger than the L1 cache, some analysis of the program's locality of reference would be needed to understand how much benefit the caches provides. This type of analysis is in most cases fairly difficult to do analytically; it's much easier to just test the program on both architectures. CodeTalker (talk) 16:23, 7 November 2018 (UTC)[reply]

I can't really directly compare the two because I have some Sandy Bridge i7s but I'm thinking about buying a Xeon workstation. The mix of integer operations and memory operations will vary from program to program, but the memory-intensive stuff mainly accesses the memory in sequence. The i7s have the standard caches. The workstation I'm considering has two 12-core Xeon E5-2695v2 running at 2.4GHz, 64GB of ECC RAM, but I don't know about the memory cache sizes. Bubba73 ^{You talkin' to me?} 02:16, 8 November 2018 (UTC)[reply]

Depends what you are doing but I've generally found passmark (cpubenchmark.net) to be reasonably predictive. 173.228.123.166 (talk) 20:49, 10 November 2018 (UTC)[reply]

November 8

ImageMagick

I'm trying to use ImageMagick to crop a bunch of images of various sizes. I want to remove the leftmost 10% and the rightmost 10% of each image. Let's say the image is 1000 width by 1000 height, I want to remove the leftmost 100x1000 rectangle, and the rightmost 100x1000, so that I end up with an resulting image of 800 width by 1000 height. Reading its manual[1], this is seems easy to do using the -crop command if all the images sizes were identical, so that I can pre-calcuate the crop rectangle XY coordinates in advance. But when the input images have different dimensions, I can't seem to find a way to use percentage values to specify the crop rectangle size and location. Any and all help would be much appreciated. Mũeller (talk) 12:28, 8 November 2018 (UTC)[reply]

@Mũeller: The section you linked tells you see Image Geometry for complete details about the geometry argument. A bit more hunting finds that page, based on which I guess (without having tested it) that what you want is -gravity Center -crop 80x100%+0+0 image.out. It does not seem possible to specify offsets in percentages, but since you want to crop an equal amount left and right, you can crop "from the center". Tigraan^{Click here to contact me} 12:43, 8 November 2018 (UTC)[reply]

Thank you so much! That worked perfectly! Mũeller (talk) 15:19, 8 November 2018 (UTC)[reply]

Resolved

November 9

Can people rob a mobile phone having just the NUMBER?

I ran across an article that made it sound like cramming (fraud) could be done by anybody that has a mobile phone number, which seems hard to believe. But the FTC makes it sound the same way. Our article Cramming (fraud) makes it sound like somehow cashing a rebate check is needed, or something. What's the truth? How hard is it to take a payment from a mobile account?

Additionally, I'm curious if this is being done to "burner" phones (TracFone and cogeners). Those don't have a monthly bill, but could scammers take money out of the accumulated minutes or something?

Also, is this actually useful for a small legitimate website as a way of collecting money? How much is the phone company's markup, and are there onerous bureaucratic requirements only a scammer could pass? Wnt (talk) 13:14, 9 November 2018 (UTC)[reply]

The scheme involved here - as detailed in this lengthy report from the FTC - requires your phone carrier to accept the charge first, and then to forward the charge to you in your bill. In a sense, your telephone service provider is acting as a credit-provider to a third-party, on your behalf - and consequently, it is the responsibility of the telephone service provider to evaluate the risks of extending credit to a possibly-non-creditable third-party.

So, when you ask whether anyone can conduct this type of scam, the answer is "no." Only people who are trusted by your phone company would be able to get money out of this scheme. That category of merchants - legitimate or otherwise - would send a bill to your phone company; your phone company would pay them, track the charge, and some time later, you'd receive the bill. Functionally, it only works for merchants who are "white-listed" - authorized by your service provider to levy a charge.

That bureaucratic step alone is enough to make this type of scam difficult to execute. If a random individual, with no legitimate credentials and no legitimate purpose, began a large-scale effort to send charge forwarding or "other forms of carrier billing arrangements" to a major company like AT&T, they would just ignore you. You would never get any money from AT&T out of the scheme, and the people you attempted to victimize would never know that you were hassling their carrier with fraudulent paperwork; and the more that you significantly attempted this effort, the greater the probability that somebody would pursue civil or criminal charges against you.

The scam works best against the customers of little tiny mobile service carriers. The people who run those carriers might not realize that when they enable this technical service, they're effectively offering credit to anyone who asks for it - which is always a recipe for attracting scam-artists, even if it attracts other legitimate users as an ancillary detail.

Large and respectable phone providers will only honor charges billed from large and respectable merchants. This is where accountability comes in to play; the bigger the scam you run, the harder it would be for you to stay hidden while conducting fraudulent activity.

Like everything else in commerce, it is possible for a few bad guys to make a little scam work for a little while - but the bigger they get, the harder it is for them to hide; and if they don't get large, they don't get any meaningful amount of money. Taking it mainstream would require hiring and paying more bad-people to help with the details. Taking it mainstream would also raise the hackles of the end-consumers, and then by proxy would raise the hackles of the major carriers, who would cease forwarding the charges from that particular scammer.

For the same reason, cheque fraud doesn't work, even there's no real technical protection to prevent a bad check. A check is basically just a piece of paper with a bunch of numbers on it. You can walk into any major bank in the United States and try to cash a totally fictitious check from a totally fictitious account. Most big banks would verify the details, and would throw you out if the account was false, and even if it was legitimate, they won't give you money if you don't have valid ID, already have a valid account, and demonstrate the other things that scammers don't typically want to present (because they don't want to get caught).

Some smaller banks (like those yucky payday loan establishments) might actually let an anonymous entrant walk into the store and cash a check with no questions asked. They incur the risk that you might be scamming them, and they mitigate this risk by taking most of your money from you up front before they cash the check. They also mitigate their risk by associating with the scary folks in the dark alley they usually keep behind their not-so-pleasant store-front: if your check is bogus, they find you and get their money back. We have an awfully white-washed article sub-section on their ... ahem, "aggressive collection practices."

Nimur (talk) 22:39, 9 November 2018 (UTC)[reply]

November 11

mass conversion to MP3

I drive a vehicle that can play MP3 files from a thumb drive. As fate would have it, most of my music files are in another format, being from CDs ~~untimely~~ ripp'd by iTunes, so I didn't have quite enough music for a recent six-hour trip.

Is there (in MacOS) a convenient way to copy thousands of AAC files to MP3? —Tamfang (talk) 05:09, 11 November 2018 (UTC)[reply]

Depending on your definition of convenient, it can be done in itunes. Henry ^Flower 15:30, 11 November 2018 (UTC)[reply]

Or not. Where that page says I should look for “Create MP3 Version” in the menu, I find only “Create AAC Version” (from AAC files)! —Tamfang (talk) 23:07, 11 November 2018 (UTC)[reply]

If you are willing to work in a command box, FFmpeg can convert audio files (not just video). Graeme Bartlett (talk) 22:36, 11 November 2018 (UTC)[reply]

If by "command box" you mean Unix shell, that's fine, I didn't get where I am today without writing bash scripts! —Tamfang (talk) 23:07, 11 November 2018 (UTC)[reply]

I have found Foobar2000 to be a great program for mass converting to MP3. It can resample, filter, make it so the loudness doesn't vary so much from song to song, etc. I just run it on my Windows box (I use Windows 10 where I have to and Slackware whenever I can -- love Neovim, hate Word, use Libre Office when a client insists on docs in Word format) but they claim to have a version for mac [ https://www.foobar2000.org/mac ]. I haven't tried it, but Foobnix might be an equivalent for Linux: [ http://foobnix.com/en/description.html ]. If you try either of those, please drop me a line on my talk page so, if possible, I can do one less thing on Windows and one more thing on Linux. --Guy Macon (talk) 23:26, 11 November 2018 (UTC)[reply]

CAD and gaming graphic cards

I was told that CAD software and gaming software use kinda different graphic cards. CAD professionals would prefer Quadro and Gamers would rather buy GeForce. Basically the rationale is that CAD need fidelity up to the pixel, and games need FPS, the more the better. However, what's the big deal if CAD software gets one pixel wrong? It's not as if we could see individual pixels. How big of an issue is this distinction? --Doroletho (talk) 20:41, 11 November 2018 (UTC)[reply]

CAD users will use large monitors where they probably can see one pixel out. If the freehand drawing is out then the design will be wrong, so the monitor should represent what the designer wants to draw accurately. I don't expect graphic cards will make this kind of error anyway, but the CAD designer will need large and multiple monitors, possibly with good colour resolution and depth. Graeme Bartlett (talk) 22:34, 11 November 2018 (UTC)[reply]

The needs are different, but what speaks for the need for a different GPU? Couldn't they make a multi-purpose GPU? What makes the design of an architecture for speed be different than designing for precision? After all, CAD or games, the GPU must be flexible enough to deal with different kinds of CAD and games. --Doroletho (talk) 22:53, 11 November 2018 (UTC)[reply]

The requirements really are different. With games it's all about speed, speed, and more speed, and if the trees whipping by on a blur or the rocket that is about to kill you look a bit off, nobody cares. With CAD, you do care.

Drivers are also a big difference. The CAD vendors write drivers that are highly-tuned to the exact specifications of the CAD cards, and there is very little variation for them to deal with. Gaming cards come from a multitude of vendors who often deviate from the original reference design. This is really the main dealbreaker. If you are using, say Solidworks, you use the computer and graphics card they recommend and support.[2][3]

Another huge difference involves power consumption. Gaming cards produce a lot of heat, but they generally do it in short bursts. CAD cards are used for 8-12 hour work days, and are often given 24/7 rendering tasks in the background. They are also quieter; a bunch of screaming fans pumping a ton of heat into the room might be OK for a gamer wearing headphones, but not in an office with 30 workstations in one room.

And don't even get me started on the difference between mechanical CAD and PWB layout... --Guy Macon (talk) 23:50, 11 November 2018 (UTC)[reply]

Another major detail is whether the vendor of a specific software - say, Autodesk (the makers of AutoCAD and many other popular tools) - have specifically certified that they design and test their software on a specific graphics hardware and software configuration.

The vendor may publish generic requirements - for example, the Autodesk tool is compatible with any "Direct3D®-capable workstation class graphics card" - but when you're buying software that costs more than your house, it's worth knowing that a team of engineers will stake their professional reputation on the specific details, and will publish documentation and provide support for your configuration.

Nimur (talk) 18:47, 12 November 2018 (UTC)[reply]

November 12

Taking more than one picture to enhance quality

When you take 100 pictures of the same object, while moving the camera a tiny bit and find out where the pictures overlap, combining them should yield a higher resolution than what the actuall chip is really capable of. (In short: the camera can only see 1*1cm pixels which are averages of 1*1mm pixels. In the next picture all 1cm pixels are moved 1mm to the left. You now have 2 new averages, so you can work out what happened in that 1mm)

What's the name of this algorithm, if it exists, and is it used often on consumer devices? For instance, my phone doesn't have an option that says "keep camera aimed at the object for at least 5 seconds" to make a hi-res picture. It is however clever enough to make a 360 degrees picture and stitch the individual pictures together automatically.

Joepnl (talk) 19:25, 12 November 2018 (UTC)[reply]