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# Wikipedia:Village pump (technical)

 Policy Technical Proposals Idea lab Miscellaneous
The technical section of the village pump is used to discuss technical issues about Wikipedia. Bug reports and feature requests should be made in Phabricator (see how to report a bug). Bugs with security implications should be reported differently (see how to report security bugs).

Newcomers to the technical village pump are encouraged to read these guidelines prior to posting here. If you want to report a JavaScript error, please follow this guideline. Questions about MediaWiki in general should be posted at the MediaWiki support desk.

Click "[show]" next to each point to see more details.
If something looks wrong, purge the server's cache, then bypass your browser's cache.
This tends to solve most issues, including improper display of images, user-preferences not loading, and old versions of pages being shown.
No, we will not use JavaScript to set focus on the search box.
This would interfere with usability, accessibility, keyboard navigation and standard forms. See bug 1864. There is an accesskey property on it (default to accesskey="f" in English), and for logged in users there is a gadget available in your preferences.
No, we will not add a spell-checker, or spell-checking bot.
You can use a web browser such as Firefox, which has a spell checker.
If you have problems making your fancy signature work, check Wikipedia:How to fix your signature.
If you changed to another skin and cannot change back, use this link.
Alternatively, you can press Tab until the "Save" button is highlighted, and press Enter. Using Mozilla Firefox also seems to solve the problem.
If an image thumbnail is not showing, try purging its image description page.
If the image is from Wikimedia Commons, you might have to purge there too. If it doesn't work, try again before doing anything else. Some ad blockers, proxies, or firewalls block URLs containing /ad/ or ending in common executable suffixes. This can cause some images or articles to not appear.
For server or network status, please see Wikimedia Metrics.
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Hello, I've rewritten User:Dr pda/prosesize.js to be more modern and maintainable at User:Galobtter/scripts/prosesize.js. Most of the changes are internal, with the main user-facing changes are to remove the arbitrary disabling of the script on certain skins (e.g timeless) when the script works just fine on all desktop skins and a fixing of a bug in the calculation of reference text size. As prosesize is a very widely used user script (>2000 uses [1]), it seems an ideal candidate to become a gadget. If this becomes a gadget, I also propose replacing the content of User:Dr pda/prosesize.js to be mw.loader.load( ['ext.gadget.prosesize'] ), i.e to load the gadget directly so the old code no longer needs to be maintained. Galobtter (pingó mió) 07:31, 14 November 2019 (UTC)

If this becomes a gadget, I'd instead suggest changing User:Dr pda/prosesize.js to:  if ( mw.user.options.get('gadget-prosesize') === null ) new mw.Api().saveOption('gadget-prosesize', '1');  instead, so that the gadget gets enabled directly rather than get loaded via the user js page; and Special:GadgetUsage would also show an accurate number of usages. SD0001 (talk) 08:07, 14 November 2019 (UTC)
That seems reasonable. Galobtter (pingó mió) 18:00, 14 November 2019 (UTC)
There is a typo at (See here for details.); should be a closing  there. Also, color me salty about mw.notify( 'Prosesize does not work with the Visual Editor.' );, but can't do anything about that on my part. --Izno (talk) 23:23, 14 November 2019 (UTC)
Thanks, fixed. Word count should at least be workable with VE (html size cannot be due to the differing html used by VE and the regular editor); it is my intention to get prosesize working with VE eventually but the last time I tried to deal with anything VE it went badly so I'll need to find the time to do it properly. Galobtter (pingó mió) 05:52, 15 November 2019 (UTC)
Izno and Galobtter, there is a page at mw:VisualEditor/Gadgets that allegedly contains some useful information and a couple of worked examples, whenever you feel up to tackling it. Ping me if you get stuck, and I'll see if I can find someone who understands it for you. Whatamidoing (WMF) (talk) 00:19, 26 November 2019 (UTC)
Highlighting in the new script seems busted. Also, there's a (somehow blue) link to Wikipedia:Prosesize, which is obviously wrong/missing something. Headbomb {t · c · p · b} 23:35, 14 November 2019 (UTC)
Headbomb, oops, the code for loading the css was broken. I haven't created the page yet, but Wikipedia:Prosesize would be the page describing the gadget. Galobtter (pingó mió) 05:47, 15 November 2019 (UTC)
working now, thanks. Headbomb {t · c · p · b} 05:50, 15 November 2019 (UTC)
Quick bump for more comments before this gets archived. Galobtter (pingó mió) 05:22, 19 November 2019 (UTC)
Support gadgetizing (gadgetifying?). User seems relatively inactive and community maintenance would be a good thing for the 2k users. Wug·a·po·des 03:41, 22 November 2019 (UTC)
• Support. Popular userscripts that meet the WP:Gadget criteria are better off as gadgets (including in terms of maintainability and performance) - Evad37 [talk] 10:37, 24 November 2019 (UTC)
• I was reading Evad's tech report and upon viewing Wikipedia:User scripts/Most imported scripts had the thought that the prose size scripts would make for good gadget candidates. Lo, the next paragraph was a link to this discussion! So, yes, support, but I have a few questions. "File size" is vague—if it's the size of the HTML document, call it "HTML document size" or "total size"? On USS Chesapeake (1799)'s text-only prose size, prosesize.js spits out "24 kB" and User:Shubinator/DYKcheck.js spits out "24986 characters"—should yours round up to 25 kB if it's going to leave off digits? (Would it be worth combining those DYK features into this one? I gave up on prosesize.js because DYKcheck.js was more human-readable: characters instead of kB.) And is there a reason why this function isn't baked into the sidebar's "Page information" link? (not watching, please {{ping}}) czar 01:16, 2 December 2019 (UTC)
Yeah I have I renamed file size to "HTML document size" and rounded the bytes rather than truncated it - thanks for the suggestions! Galobtter (pingó mió) 06:16, 4 December 2019 (UTC)

## Too often I get this "Edit conflict: Talk - Someone else has changed this page since you started editing it, resulting in an edit conflict."

Whenever I help out editing an article or talk page, I nearly always get this notification "Edit conflict: Talk - Someone else has changed this page since you started editing it, resulting in an edit conflict." I've learned to live with it and work around it:

1. copy/pasting my text and then hit the blue "Publish changes" button a second time; sometimes it then publishes my text;
2. if it doesn't, I have my text in the copy/paste memory of my computer and can again paste my text and then hit the blue "Publish changes" button a 3rd time and then mostly my changes are finally in the article or talk page.

Anybody know's what's going on? Is it because I have too many observations and reversed edits by moderators? I really study the reasons in case my additions are not accepted, at times I don't agree and I find the - how are these wikipedians called - I think "arbiters" - extremely blunt - especially when I've put 10 minutes to an hour of editing and documenting an article or clearly stated I wanted to start an article and need to park it somewhere to continue it later because my kids of wife walks in and need my attention. Anyway - thy. --SvenAERTS (talk) 08:27, 14 November 2019 (UTC)

It often happens to me when I've spent time making a single substantial edit while other editors are making many small edits. So, where possible, the solution is to reduce the size of your edits: work by making many small edits rather than a few longer ones, then you're less likely to be interrupted in this way. Where this isn't possible, you just have to get round it as you say you do. Peter coxhead (talk) 10:16, 14 November 2019 (UTC)
What's happening is described at Help:Edit conflict. If you're planning on making a long edit, make a small edit first to add the {{inuse}} tag to the top of the page. Don't forget to remove it afterwards, though. Yunshui  10:30, 14 November 2019 (UTC)
This edit suggests that you clicked twice, perhaps inadvertently - I have a mouse that sometimes double-clicks when I intended a single click, because of contact bounce. --Redrose64 🌹 (talk) 21:21, 15 November 2019 (UTC)
@Yunshui: thx all. By the way, what is the name of the coding language with these double accolades and piping - is that java or php or python? ThySvenAERTS (talk) 09:44, 19 November 2019 (UTC)
Technically it's a markup language rather than a programming/coding language - it's called Wikitext. Yunshui  09:47, 19 November 2019 (UTC)

### Constant edit conflicts

So it seems, every time I make an edit, even if the last edit was months ago, that when I click "Submit", I get the edit conflict screen. I've disabled any of the functions in Beta and Preferences that might have caused it, and I still get it. Anyone know why? And for that matter, it seems the wiki software will immediately revert the edit in my name so I'll in in the history "PrussianOwl +380", and in the next line "PrussianOwl -380". I asked this at the Help Desk and they said to try asking here. Thanks, PrussianOwl (talk) 02:39, 15 November 2019 (UTC)

especially when I've put 10 minutes to an hour of editing and documenting an article or clearly stated I wanted to start an article and need to park it somewhere to continue it later because my kids of wife walks in and need my attention.
In that case you should first flesh out the whole article in a subpage of your user page, either as a draft or in a sandbox, before submitting it for publishing in the main space. Guarapiranga (talk) 11:02, 22 November 2019 (UTC)
PrussianOwl, have you tried editing in mw:safemode? Whatamidoing (WMF) (talk) 00:22, 26 November 2019 (UTC)
Thanks, I'll have to try that! UPDATE: It works! It must be a script I'm using then right? UPDATE 2: So I tried removing all the scripts I installed one by one since I started seeing the problem, and I still saw it. I also made sure to delete my cache between each attempt. I already checked my Beta and preferences and disabled anything involving edit conflicts or saving edits, so I'm out of ideas. Also, if I click away from the edit conflict screen, my edits show up on the page as live. PrussianOwl (talk) 02:28, 26 November 2019 (UTC)
Do you have anything (especially anything that isn't popular) enabled in the gadgets for Special:Preferences? Or global scripts (on Meta) that you might have missed? Whatamidoing (WMF) (talk) 20:19, 27 November 2019 (UTC)
Nothing global, but quite a few gadgets on. Nothing that involves saving or edit conflicts though. PrussianOwl (talk) 03:10, 29 November 2019 (UTC)

## Linking signature timestamps to diffs

Is there a way (a script perhaps) for linking the signatures timestamps in talk pages to their diff? Guarapiranga (talk) 23:05, 20 November 2019 (UTC)

That would be cool. If there isn't, a starting point for code that could be modified (for someone without familiarity with the API) is User:Anomie/unsignedhelper.js, which finds the edit in which a selected piece of text was added. It might be a performance problem to walk through a whole page to link all the timestamps, so you probably wouldn't want to do it automatically. Best to select the desired sig and then run the tool for that one only, I think. —[AlanM1(talk)]— 23:50, 20 November 2019 (UTC)
I wouldn't recommend walking the whole history like the unsigned script does. Often you can probably find the right revision by looking for the one with the matching timestamp. Occasionally it might be off by a few seconds, or occasionally there might be multiple revisions with the same timestamp. Anomie 12:52, 21 November 2019 (UTC)
Yes, I do that manually (like literally ctrl-C + ctrl-F). As AlanM1 said, it would be cool to see the link already there on the screen (rather than searching through the history). Alternatively, the diff link could be hardcoded to the timestamp by the ~~~~ signature. Guarapiranga (talk) 03:40, 22 November 2019 (UTC)
Can Sinebot do that, slakr? Guarapiranga (talk) 01:45, 23 November 2019 (UTC)
The mw:Editing team is looking at the next step for the mw:Talk pages project. They're talking about making some changes to wikitext (AFAICT, we still type the same four tildes, but it would automagically expand to something a little bit longer to have an official "end" marker to a comment). It's at least possible that their changes could make it a bit easier to do this. User:PPelberg (WMF), what do you think about this idea? It'd be handy to at least me to have the diff right there (good for troubleshooting the visual editor, and convenient for thanking people for their comments). Whatamidoing (WMF) (talk) 01:02, 26 November 2019 (UTC)
The whole tilde signing charade and drama when people forget to sign, and why it's not simply part of the message container like in every other discussion platform is beyond me, Whatamidoing (WMF), but that's another topic. Guarapiranga (talk) 21:51, 26 November 2019 (UTC)
, this is an interesting idea. Are you able to share what triggered this thought? The first use case that comes to my mind: making it easier to cite the specific comment you're responding to. Although, I wonder if there are other workflows you'd find this kind of functionality valuable for? And same questions to you, @AlanM1:...
Now to wikitext and signatures, I'm glad you raised this, ...
To add a bit more context: the mw:Editing team is considering creating a proposal that would involve slightly changing the wikitext generated by signatures.
The purpose for this potential change would be to make signatures on talk page more machine readable (important for functionality like mw:Talk_pages_project/replying to work reliably) and to allow for signatures on old talk pages to be updated automatically.
With the above said, the team has not yet reached a consensus about whether such changes are necessary. If you are curious to learn more about these potential changes or have thoughts to share, visiting this discussion in Phabricator is a great place to do so: T230653. @PPelberg (talk) 17:59, 27 November 2019 (UTC)
Precisely what you did there, PPelberg (WMF), linking my comment's diff. In other discussion platforms, e.g. facebook, to link someone else's comment, one typically right-clicks that comment's date and copies over the url. Can't think of any other use case, as signatures are typically restricted to talk pages, unless you want to broaden the discussion to linking each part of an article to its latest edit and author (much like MS Word's track changes). That would be awesome! Guarapiranga (talk) 23:58, 27 November 2019 (UTC)
Guarapiranga, understood! Thank you for sharing this context. It's encouraging to see you express a need for enhancements intended to make it easier to refer to specific comments within a discussion and by extension, better understand/follow what is being talked about in talk page conversations. [1]
I say this because these are two areas we hope to improve as part of the mw:Talk_pages_project. With this said, "What enhancement(s) might we implement to make it easier to refer to specific comments within a discussion and by extension, better understand what is being talked about in talk page conversations?" is still an open question.
If you'd like to stay up to date on our progress towards answering these, you might follow the mw:Talk_pages_project/Updates page – we use this page to share information that includes what features we are considering working on and when.
@PPelberg (talk) 01:46, 3 December 2019 (UTC)

## Slowdown on WP

Hi. Has anyone else noticed a slowdown over the last 12/24hrs on EN WP? Pages seem to take longer to load, sometimes taking a while to access talkpages too. I've also noticed that the tools box on the left-hand side of the page also takes an age to load too. I've disabled some scripts in my custom css/javascript pages, but that doesn't seem to have helped. Using Firefox in the UK if that helps. Thanks! Lugnuts Fire Walk with Me 11:15, 23 November 2019 (UTC)

I've noticed it, too. —[AlanM1(talk)]— 11:25, 23 November 2019 (UTC)
Thanks Alan. Other slowdowns I've noticed - taking ages to save a talkpage, clicking on the "what links here" and trying to view the diffs via the edit history. Please can someone switch something off, and then switch it back on again! Lugnuts Fire Walk with Me 12:17, 23 November 2019 (UTC)
Same here, though does not appear to affect Wikipedia namespace. Keith D (talk) 12:19, 23 November 2019 (UTC)
Well whatever was happening, it seems to be OK now (famous last words...) Lugnuts Fire Walk with Me 15:14, 23 November 2019 (UTC)
Been happening on and off for me, but a little longer than 24h. More like a day and a half, I think. Assumed it was my internet connection being a PITA again, but if others experienced the same, it probably wasn't on my side for once. Agree that it currently seems to be okay, but I thought that at least thrice yesterday as well, so... AddWittyNameHere 15:24, 23 November 2019 (UTC)
It was driving me nuts earlier today. Doug Weller talk 16:03, 23 November 2019 (UTC)
I'm still finding WP sluggish, even right now. It was very slow earlier today, though. --IJBall (contribstalk) 04:26, 25 November 2019 (UTC)
@IJBall: Yeah, been experiencing some slowness on my side today again as well. Always fun when trying to do things that are already mind-numbingly boring repetitive on the best of days... AddWittyNameHere 05:44, 25 November 2019 (UTC)
Perhaps some clues can be found in "I was referred here: Wikimedia Foundation error" (below) Pi314m (talk) 22:09, 1 December 2019 (UTC)

## Twinkle not working

So I log on to Wikipedia one day and go to the recent changes page to undo some vandalism. I control-click on a "diff" button to open the edit in a new tab, click on the rollback(VANDAL) button, and Twinkle, as usual, opens the vandal's talk page so I can warn them. But, much to my surprise, the button on the side to warn, welcome, etc., are not there! So, I warn them manually, go to my Preferences page, and Twinkle is turned on. I try turning it off and on, and it still doesn't work. Twinkle's undo mechanism still works normally, but the buttons on the right side are all gone! Does anyone know what happened? TL The Legend talk 21:41, 24 November 2019 (UTC)

Is this still troubling you? GUYWAN ( t · c ) 19:58, 25 November 2019 (UTC)
@Guywan: No, I found the buttons near the bottom, on the left side of the page. TL The Legend talk 04:00, 26 November 2019 (UTC)
What skin do you use, TL The Legend? Timeless? SD0001 (talk) 06:00, 26 November 2019 (UTC)
@SD0001: Yea.TL The Legend talk 03:12, 28 November 2019 (UTC)

In Timeless skin, the Twinkle links are located within the "Page tools" portlet (menu); the location of this depends on the window size. Its in the right sidebar if the window is large enough. For medium-sized windows, all the right-column links (including the Twinkle links) are shifted to the left column. In smaller windows (and tablet-sized devices), they become dropdown menus along the top (and for very small/mobile devices symbols are used instead of words for the menu titles).

- Evad37 [talk] 13:16, 28 November 2019 (UTC)

## Sticky table headers: Firefox vs Chrome

I noticed in Firefox table headers remain fixed at the top of the page when scrolling through a long table (albeit with no separating line between header and table), but not in Chrome-based browsers. Is that a Wikimedia or Firefox feature? Cheers. — Preceding unsigned comment added by Guarapiranga (talkcontribs) 22:11, 26 November 2019 (UTC)

Firefox. MediaWiki emits a tbody element, but not a thead element - the row containing the th elements are inside the tbody and not where they ought to be, in a thead. --Redrose64 🌹 (talk) 22:34, 26 November 2019 (UTC)
Is that bc any row can be made header row in wikitext?
Either way, that's a really cool FF feature. Might swing me back to using it instead of Brave. Guarapiranga (talk) 05:03, 27 November 2019 (UTC)

1. Can you tone down the frequency of the ads for the app on mobile? They're really annoying, I must've seen them like 20 times today until they stopped showing up. They only went away after I misclicked the link and got taken to the Scroogle Play page. 2. Consider linking to F-Droid instead? It's FOSS like Wikipedia and unlike $croogle. 93.136.16.102 (talk) 04:45, 27 November 2019 (UTC) According to List_of_Wikipedia_mobile_applications the official Android app is already on FDroid. RudolfRed (talk) 21:17, 27 November 2019 (UTC) ## SineBot down again It appears SineBot (talk · contribs) has died again and hasn't been signing posts for the past week. In an attempt to be a bit more pro-active about the issue, I have created prototype of an open-source replacement in PyWikiBot. The code is at User:Ritchie333/arcsinebot.py; it doesn't do anything more than check common talk namespaces edited in the past five minutes, and reports any diffs it thinks might need to be signed. It doesn't do anything sophisticated such as check if the diff is editing an existing post, for example, which absolutely has to be done before it can be considered usable. I realise this is reinventing the wheel somewhat, but with an open-source solution, we can all collaborate in fixing it so it works properly, and the code can be migrated across to other servers (ideally Labs) so this will stop being a long term issue. Ritchie333 (talk) (cont) 15:39, 27 November 2019 (UTC) I seem to recall you were interested in a project like this. I don't particularly want to do this, and what I've created is merely the result of tinkering over lunch, but necessity is the mother of ... Ritchie333 (talk) (cont) 15:57, 27 November 2019 (UTC) FWIW it's up again, as of about four hours after this post. ~ Amory (utc) 15:48, 28 November 2019 (UTC) ## PROD with Twinkle When I try to nominate an article for PROD with Twinkle, I get this: File:PRODError123.png. I waited a while, but I still have the same screen. Something similar happens with BLPPROD. Do you know why that is? Please make sure that you view the file because I'm going to have an admin delete it soon. This happens with any article I nominate. Interstellarity (talk) 20:43, 27 November 2019 (UTC) I just tried it on this file, and it worked okay. –Deacon Vorbis (carbon • videos) 20:50, 27 November 2019 (UTC) Deacon Vorbis, If it works for you, what could I try to fix it? Also, in the future, please ping me in your responses. Interstellarity (talk) 20:57, 27 November 2019 (UTC) What's your OS name, OS version, browser name, and browser version? -FASTILY 07:03, 28 November 2019 (UTC) Fastily, Windows 10 Home 1903 and Firefox 70.0.1 Interstellarity (talk) 12:08, 28 November 2019 (UTC) If it happens again, can you add the console errors from steps 6 of WP:JSERROR? That'd help diagnose the issue, especially given that your NPPSchool instructor was able to do so on the article in question. ~ Amory (utc) 10:49, 28 November 2019 (UTC) Amorymeltzer, TypeError: ts.setLookupNonRedirectCreator is not a function Interstellarity (talk) 12:10, 28 November 2019 (UTC) I tried to see if I could repeat the issue in Chrome. I did. Interstellarity (talk) 13:10, 28 November 2019 (UTC) This (and I presume your related AfD issue) is because of a hotfix for User:SD0001/DYK-helper.js that SD0001 put in. Basically, DYK-helper wasn't working, so now that script is importing an outdated version the morebits library, which is overriding the Twinkle gadget and causing certain functions that were recently added to fail. Until that is fixed, disabling DYK-helper should make your PROD and AfD work. ~ Amory (utc) 15:43, 28 November 2019 (UTC) I have had a similar problem for the last few days with PROD. The initial TW window opens and then nothing else happens (I don't see any error message). With AFD, I get the same problem as described below. The AFD is created/added to the log but the final step to put the notice in the article just hangs. Windows 10 Home/Firefox. MB 16:36, 28 November 2019 (UTC) Same issue: you also import User:SD0001/DYK-helper.js in your common.js. ~ Amory (utc) 17:00, 28 November 2019 (UTC) I fixed the problem. Thanks, Amorymeltzer. Interstellarity (talk) 19:26, 28 November 2019 (UTC) @Interstellarity and MB: Should be fixed now. Sorry for the trouble. You can add back the DYK-helper if you removed it, it should now work w/o interfering with TW. Thank you Amorymeltzer. Dunno how I didn't think of it earlier! SD0001 (talk) 19:30, 28 November 2019 (UTC) You did write it, after all! 😛 ~ Amory (utc) 21:13, 28 November 2019 (UTC) — Preceding unsigned comment added by Amory (talkcontribs) ### Twinkle and AfD This is related to the issue above about with PROD. When I nominate an article it works as intended except put the notice in the article. The article is: Random (compilation album). I manually added the notice. Please ping me in your reply. Interstellarity (talk) 13:39, 28 November 2019 (UTC) ## List of past edits? The recent changes list apparently only extends 30 days in the past. However, this data must be in the database in order to display page histories. Is ther a way to see a list of changes made starting at s specified time and date, going back months or preferably years? This would be for statistical analysis of Wikipedia edits, in an attempt to repeat User:Opabinia regalis/Article statistics with a larger data set and a wider spacing of sampled times, although I can see other possible uses. Does the interface make this available in any way, or would one have to download a data dump and query it? DES (talk)DESiegel Contribs 20:49, 27 November 2019 (UTC) @DESiegel: Most of what I see at User:Opabinia regalis/Article statistics could be queried from the database directly, such as with Quarry. The kind folks at WP:RAQ I'm sure could help you construct some queries if you're having trouble. Exceptions are things involving content itself, such as detecting vandalism reverts (you could count usage of Rollback/Undo but that's not necessarily reverting vandalism), and detecting copyediting/formatting/template changes. The latter is probably still doable but would involve complicated and inefficient scripting. 21:42, 27 November 2019 (UTC) Thanks, MusikAnimal, that is new to me. I'll have to explore. What I am aftre is a lsit of diffs with matching timestampa 9or version IDs from which diffs could be created. If the relevant user ID and namespace could be returned or filtered on, that would be even better. Once I ahve those classification will probably be manual. Thanks. DES (talk)DESiegel Contribs 21:47, 27 November 2019 (UTC) ## New video player beta feature updates I've posted a quick note on upcoming changes to the "New video player" beta feature, which we're hoping to take out of beta soon. I've made some major changes to show a larger player, have less impact on JavaScript download size, and work more comfortably on mobile. Please keep giving feedback either through the feedback page there or as tasks on Phabricator; there's plenty to keep improving! --brion (talk) 22:02, 27 November 2019 (UTC) ## Reload icon and right arrow in sr.wikipedia mobile history desc Could someone here on English Village Pump know why is reload icon in sr.wikipedia mobile history description (left of the "Ову страницу је последњи пут уредио..." text) only partially visible (its right part is cut off)? Also, the small right part of the arrow on the right is cut off. This happens for me on my mobile screen mobile (m. in URL) reading and if I enable rotation and rotate the screen, everything gets fully visible. If someone could help to report the bug or fix it, it would be useful. Width of my mobile screen is about 6 cm (height 11 cm, becomes width when horizontally orient rotated screen), latest Android (if that would help replicate the problem). --Obsuser (talk) 23:09, 27 November 2019 (UTC) This has been reported at phab:T238681. It's not specific to that wiki. – Ammarpad (talk) 11:16, 28 November 2019 (UTC) ## Reset password without email Hello. My friend has changed his password a few years ago and don't remember it now. Is there any way that he can reset it without email? I know that it would be easier to just open a new user account but he wants to keep all his edit history, watchlist and so on. I'm from hywiki and since it is a small community many active users know him personaly and can guarantee that no one wants to steal that account. I know that this is not the best place to ask this kind of questions but I don't know a better place. --ԱշոտՏՆՂ (talk) 11:34, 28 November 2019 (UTC) Unfortunately, if he doesn't remember his password, and didn't give an email address (or no longer has access to this address), there's no way to prove to the software that he's the same person. 37.26.149.183 (talk) 12:17, 28 November 2019 (UTC) Sometimes devs/sysadmins can reset password if people vouch for the person. –xenotalk 12:47, 28 November 2019 (UTC) CheckUser can be reliably used to verify his identity in cases like this. It's the best, however, if the person has some sort of identity code and can use it to establish his identity or if it's a known person in real life and another user in good standing can confirm his identity. 37KZ (talk) 13:33, 28 November 2019 (UTC) Thank you!. @xeno, should I open a phabricator task for that?--ԱշոտՏՆՂ (talk) 14:55, 28 November 2019 (UTC) I think that is the process but I wouldn’t know what tags to apply etc., xaosflux any idea? –xenotalk 18:25, 28 November 2019 (UTC) You can try the Trust-and-Safety phab tag, and it is in no way guaranteed. — xaosflux Talk 19:41, 28 November 2019 (UTC) ## Question I get errors similar to this (in my browser's console): load.php?lang=en&modules=jquery|jquery.ui|mediawiki.toc&skin=vector&version=10g3d:130 [Report Only] Refused to connect to 'https://xtools.wmflabs.org/api/page/articleinfo/en.wikipedia.org/Wikipedia:Village_pump_(technical)?format=html&uselang=en' because it violates the following Content Security Policy directive: "default-src 'self' data: blob: upload.wikimedia.org https://commons.wikimedia.org meta.wikimedia.org *.wikimedia.org *.wikipedia.org *.wikinews.org *.wiktionary.org *.wikibooks.org *.wikiversity.org *.wikisource.org wikisource.org *.wikiquote.org *.wikidata.org *.wikivoyage.org *.mediawiki.org wikimedia.org". Note that 'connect-src' was not explicitly set, so 'default-src' is used as a fallback. What does it mean? Regards, GUYWAN ( t · c ) 21:16, 28 November 2019 (UTC) Ah, it appears to be caused by the mw:XTools gadget for some reason. (Disabling XTools stops the error.) GUYWAN ( t · c ) 21:25, 28 November 2019 (UTC) @Guywan: XTools is being loaded from a domain that isn't whitelisted, so it gets reported by the Content Security Policy directive shown in the error message. But since it's currently in Report Only mode, XTools (and anything else generating similar errors) still actually work – for the moment anyway. See phab:T220475 for the task for XTools, and phab:T28508 for the general task for the Content Security Policy. - Evad37 [talk] 00:10, 29 November 2019 (UTC) ## Can we get a new list for Wikipedia:Templates with red links? As far as I can tell, the current sets of links are from 2011. Can a new and correct set of lists be generated for templates now containing red links? BD2412 T 22:42, 28 November 2019 (UTC) It looks like EmanWilm might know a bit about this? — xaosflux Talk 00:22, 29 November 2019 (UTC) It doesn't seem like it should be that hard a task. BD2412 T 23:53, 1 December 2019 (UTC) ## IP tools option missing on contribs and user pages for ranges On a user or contribs page for a single IP address (e.g., Special:Contributions/192.168.1.1), the "User" tab at the top of the page has an "IP lookup..." option with "WHOIS", etc. on it. However, if you specify a range in CIDR notation (e.g., Special:Contributions/192.168.1.1/16), the "User" tab is not present. Is there a reason for this? I commonly need this functionality, and imagine others do too. I can (try to) put together some JS to do it, but before I do, is there an existing workaround? Should it be requested at phab (or has it been)? P.S. Note the odd presence of what are apparently user accounts masquerading as IPs. Is this an issue? As always, thanks. —[AlanM1(talk)]— 00:18, 29 November 2019 (UTC) @AlanM1: I don't see a "user tab" on either of your examples - is this something you are getting from a script? (e.g. Look in safemode) If so, do you know which script is making that for you? — xaosflux Talk 00:30, 29 November 2019 (UTC) If you mean the WHOIS link in the footer at the bottom of the page, we could add that (MediaWiki:Sp-contributions-footer-anon vs MediaWiki:Sp-contributions-footer-anon-range) — xaosflux Talk 00:32, 29 November 2019 (UTC) Actually - I just added that there, seems useful. — xaosflux Talk 00:33, 29 November 2019 (UTC) (ec) @Xaosflux: Doh! Don't know why that didn't occur to me. Must be a user script. I'll dig into it. I didn't even notice the stuff at the bottom. I guess the issue exists there, too, though. (Time passes ...) and now it's resolved there. Thanks! —[AlanM1(talk)]— 00:38, 29 November 2019 (UTC) Apparently, it's in meta:MoreMenu. Reported there. —[AlanM1(talk)]— 01:01, 29 November 2019 (UTC) I commented at meta, but I believe it's because wgRelevantUserName doesn't exist for ranges. ~ Amory (utc) 01:46, 29 November 2019 (UTC) ## See article sizes in difference view. A request for article size change to be noted in the diff viewer as it is in the history, see below. Relisted to generate more discussion ~ R.T.G 07:51, 29 November 2019 (UTC) I suggest that the difference viewer shows both the size changes and absolute sizes before and after the edit for comparison, just like in the version history (list of revisions). –– Handroid7 talk 12:24, 17 October 2019 (UTC)OP was a sock please ignore the OP ~ R.T.G 11:48, 29 November 2019 (UTC) • I would definitely support this. The more information, the better. bd2412 T 12:36, 17 October 2019 (UTC) • Support: Me too. GenQuest "Talk to Me" 12:47, 17 October 2019 (UTC) • Support Sounds like a great no-brainer idea. Someone should open a Phab ticket. --Ahecht (TALK PAGE ) 14:10, 24 October 2019 (UTC) This was proposed on VP/Proposals. There didn't seem much point to it beyond amusement. I was almost going to support it for that reason myself but it's not really appropriate. Now I have a reason. Some editors like to edit a whole big long article in one edit. I do it sometimes to move the references to the reference area. People do it just to edit anything in the article and what happens is, the formatting breaks for the diff display and you can't easily tell how much info has been added and removed. Indeed, having the change amount showing in the diff, as it is in the history, would improve the ability to gauge how much change a particular edit has made. This was listed at VP/Proposals and practically nobody answered it, but this is a technical request. @Ahecht, GenQuest, Handroid7, and Bd2412: (If someone knows how to format a relisted request like this, please do because I don't...) ~ R.T.G 07:51, 29 November 2019 (UTC) • Support ~ R.T.G 07:51, 29 November 2019 (UTC) • @RTG:, why have you pasted this here, when it was originally at WP:VPR (from where it was archived more than three weeks ago)? Are you aware that it was originated by a user indef blocked for sockpuppetry? Did you notice that |Wikipedia technical issues and templates is not a valid parameter, so it's put the RfC into Wikipedia:Requests for comment/Unsorted - did you check how it shows there, there isn't even a meaningful statement, contrary to WP:RFCST. --Redrose64 🌹 (talk) 10:27, 29 November 2019 (UTC) • Because it is a technical request more suitable to this place than proposals. No, I suspected only good faith. I don't think I've done an RFC before. I went to the template page. It said something like, "put {{ref|''Category''}}. There was an infobox listing RFC categories. I assumed those were the categories from which to choose (this is not an uncommon issue). I've asked quite clearly for help wit this if that's what you're trying to do... I'll go and check the links you gave and format it the best I can from that based on that. bd2412 certainly isnt a sockpuppet. I don't know about the other two. ... So you've already changed the RFC template for me thank you but, this doesn't relate to a single page does it? Is it possible for me to list the same RFC template on Help:Diff as is listed here? Help:Diff is like new editors first help. It's not going to benefit this request very much..? , I haven't changed anything... am I still breaking stuff? I'm sorry I've seen a hundred relisted discussions and RFCs but I haven't felt the need before... Nobody wrote on it that it was a sock. It sat there for weeks. I assumed good faith, sorry. I'll er, well, Is it still broken or anything I've added a statement? Let's strike the OP. ~ R.T.G 11:48, 29 November 2019 (UTC) Proposals for new features don't belong here. It's phab:T172698 from 2017 (only mentions size change and not absolute size). PrimeHunter (talk) 12:13, 29 November 2019 (UTC) At WP:RFCST, item 2 explains the markup and provides an example; the table (which is not an infobox) shows that to put something into Wikipedia technical issues and templates, the markup is {{rfc|tech}}. I never claimed that bd2412 was a sockpuppet, I stated it was originated by a user indef blocked for sockpuppetry and the originator is the person who made the post having the earliest timestamp (12:24, 17 October 2019 (UTC)), therefore Handroid7 (talk · contribs). I don't see what Help:Diff has to do with this, it neither gives advice for RfCs nor is it a discussion page. As PrimeHunter notes, this is a phabricator matter. We cannot change the software on this side, even if we have a RfC with hundreds in support and no opposition. --Redrose64 🌹 (talk) 23:32, 29 November 2019 (UTC) • Support. I've long found it frustrating that this information is visible in the history list but not in the diffs; many of us page through diffs rather than scrolling up and down in the history list (or after doing so, rather). I'll go comment at the Phab ticket. Not interested in the back and forth above, about RfC documentation. 07:34, 1 December 2019 (UTC) ## Correct way to merge 2 infoboxes without throwing warnings on a biography Hi all, I wanted to merge {{Infobox officeholder}} and {{Infobox criminal}} and use together as 1 infobox in a biography article. But it keeps throwing warnings or it comes as a layout error. IS there a way to seamlessly merge and present 2 infoboxes into one. Both these 2 infoboxes are derivatives of {{infobox Person}}-- 13:16, 29 November 2019 (UTC) The documentation might help. Look at Martin Rees for an example. – Jonesey95 (talk) 16:19, 29 November 2019 (UTC) Thanks a lot Jonesey95. It did help. Marking as resolved. -- 20:20, 29 November 2019 (UTC) Resolved ## AfD stats down? Is AfD stats at tools.wmflabs down? I havent contributed to much other than AfD's recently. So one can easily see AfD votes in my contrib history, but they are not being reflect at wmf tools.usernamekiran(talk) 17:19, 29 November 2019 (UTC) pinging Enterprisey. —usernamekiran(talk) 17:22, 29 November 2019 (UTC) its working again. But I think Enterprisey should see this. He seems to be offline since 2 days now. —usernamekiran(talk) 20:55, 30 November 2019 (UTC) That's interesting - there's nothing in any of the logs from the 29th. usernamekiran, are there any specific contributions that aren't showing up on your stats page at the moment? Enterprisey (talk!) 21:42, 2 December 2019 (UTC) ## Getting signed out when moving between projects I'm quite certain this has been beaten to death before. But has anyone else been sporadically getting signed out when moving between enwiki and Commons? Frequently when I find self-written vanity articles or drafts that contain Commons images, I'll open the images and cross over to Commons to nominate them for deletion. Suddenly, this is sporadically causing me to be "logged out" when I get to Commons (or enwiki, if I'm moving the other way). If I click "Log in", it seems to "kick" immediately and show that I'm logged in to my account (I don't have to enter a username or password at all, it just goes right away). Last evening, this problem resulted in my IP being accidentally revealed on multiple pages (used a script to nominate an image) and I had to discreetly get ahold of an oversighter on Commons to hide it. I use Windows 10 64-bit with Google Chrome, and haven't noticed any problems up until recently. Anyone know what gives? Home Lander (talk) 17:56, 29 November 2019 (UTC) • I have had this happen at least half the time when moving between projects over the past two weeks - probably 5-6 times/day. About half the time, I will get the message saying "refresh, you're logged on centrally", but the other half of the time, I need to actually go through and log in with my password. Windows 10, current Firefox. Risker (talk) 19:44, 29 November 2019 (UTC) Risker, I don't recall that I've ever even seen such a message. Usually once I sign into one project, I'm signed into anything I cross over to. Home Lander (talk) 21:09, 29 November 2019 (UTC) Usually when this happens, I just have to wait a few seconds for it to fix itself. Occasionally, the not-too-drastic WP:BYPASS is necessary. Tip: set a global user preference that makes it immediately obvious whether you are logged-in or not - I have set MonoBook skin, which means that if I see a page that is displayed in Vector skin, I'm not logged in so know not to make edits. --Redrose64 🌹 (talk) 23:40, 29 November 2019 (UTC) ## Articles in watchlist continue to show as unread (bold) even though I've gone thru (visited) the diffs in these articles This has probably come up a number of times in the last few months, and I recall seeing this here back in March and April (Wikipedia:Village pump (technical)/Archive 173#watchlist articles not being marked as read after having been seen/visited, Wikipedia:Village pump (technical)/Archive 173#Seen changes not marked as such in the watchlist, Wikipedia:Village pump (technical)/Archive 173#Changes not being marked as read immediately). From time to time, even now, the bug will show up where entries in my watchlist that I have gone thru will continue to show as unread. Actually, only the entries for the article I had just visited will be marked as read, while all the new entries for other articles after refreshing my watchlist, following a notice that changes have occurred to articles in my watchlist, will continue to show in bold (unread). So it will briefly show one article's entries as being read, but after going to another article with changes, the first article's entries will go unread again following a refresh of the list. As I said, this happens on occasion, not all the time. Sometimes, the watchlist behavior will be normal as expected, where all entries that have been visited/read will stay that way, but other times, this bug, which has apparently been around for months now, will come up. MPFitz1968 (talk) 19:11, 29 November 2019 (UTC) Can confirm I've been having the same issue today. Ionmars10 (talk) 19:18, 29 November 2019 (UTC) ## Wikispecies infobox I have been updating the Betta articles. There is quite a bit of information that would be better summarised about the fish in the infobox, however I don't want to take away the Wikispecies infobox as this is more important in my view. How would I extend the infobox? Can I create a new Betta infobox template and incorporate the wikispecies infobox around it, and include new fields? - Chris.sherlock (talk) 04:50, 30 November 2019 (UTC) Nearly all articles on living species or groups of organisms have a taxobox, which is an infobox primarily summarising taxonomic information, but also including images, range maps and conservation status. The are part of the recommended structure for articles covered by WikiProject_Tree_of_Life. These should not be removed without discussion. The taxoboxes predate the {{infobox}} so don't use the same structure as most other infoboxes. It would be difficult to combine the two. I should also add that these taxoboxes have nothing to do with Wikispecies, which is another Wikimedia project. What sort of information were you thinking of including? There might be a case for also including a different type of infobox, although this should probably done with consensus of the relevant project. 15:30, 30 November 2019 (UTC) There is some addition information at WikiProject_Aquarium_Fishes. 15:34, 30 November 2019 (UTC) I think the info in the wikiproject is very helpful here, I'll use their suggested structure. - Chris.sherlock (talk) 06:45, 2 December 2019 (UTC) ## Collapsible content on mobile browsers I noticed collapsible templates don't work on mobile browsers (e.g. Vaccination policy). Is that intentional? Guarapiranga (talk) 04:50, 30 November 2019 (UTC) See Wikipedia:Village pump (technical)/Archive 174#Collapsible blocks in mobile version. Perhaps somebody kind would add a note to Help:Collapsing#Limitations. --Redrose64 🌹 (talk) 12:00, 30 November 2019 (UTC) Thanks, Redrose64. Done. Guarapiranga (talk) 12:16, 30 November 2019 (UTC) ## Unable to view deleted articles I am an administrator and sometimes wish to view deleted articles, usually in response to "why was my article deleted?" inquiries at the Teahouse. Recently, I have received error messages like the following: "Internal error Jump to navigationJump to search [XeLZEApAAEEAADj@w3MAAAEW] 2019-11-30 21:03:12: Fatal exception of type "InvalidArgumentException" I have used a Google Pixel 2XL smartphone for about 18 months with no similar problems until recent weeks. I use the desktop site on my phone. Can anyone shed some light on this problem? Cullen328 Let's discuss it 21:11, 30 November 2019 (UTC) Is this only when you try to view a diff? If so, it's a known problem. --Redrose64 🌹 (talk) 21:37, 30 November 2019 (UTC) (ec) I have not had a problem viewing deleted articles lately, but there is a bug bug in looking at diffs among deleted content (phab:T237709). Could you give us a specific set of actions (for example, a redlink wikipedia link to the article-name that admins would click that would/should give us the deleted history) to demonstrate what problem you see? DMacks (talk) 21:39, 30 November 2019 (UTC) The most recent example was GO Technologies, which is now being discussed at the Teahouse. Yes, my standard method of viewing deleted articles has always been to look at the most recent diff. Thanks for that link, Redrose64. I now know that I can click on the date/time and accomplish the same thing. Thanks to all for your assistance. I am grateful. Cullen328 Let's discuss it 21:49, 30 November 2019 (UTC) ## Bug in source editor - related to line wrapping? Hi, I'm just trying to edit some articles, and there appears to be a bug in the source editor that's driving me crazy. The symptom is that the cursor will appear in one place in the text, but when I type or hit the backspace key, characters are actually added or removed at a different place. Here is some example text that causes this bug on my system (Macbook with macOS 10.14.6 and Chrome 78.0.3904.108): The plant has many traditional medicinal uses. In Madagascar, the crushed plant is used for skin parasites. In Mauritius, the sap of crushed leaves mixed with salt, or a decoction of plant, is used for scabies and other skin problems. In the Seychelles and Reunion, a root infusion or decoction is taken for asthma, and also to clean the liver and kidneys. When I edit the first or second lines of that, it works correctly, but when I edit the third line, the cursor is way off. I guess it might not reproduce on your system unless your font and browser happen to be the same size... but is anyone else seeing this behavior? —Keenan Pepper 22:56, 30 November 2019 (UTC) Does it happen if you are logged out? What if you try a different browser? – Jonesey95 (talk) 00:23, 1 December 2019 (UTC) No, it doesn't happen when I'm logged out - when I'm logged out, for some reason that line wraps differently (the word "root" is on the 3rd line not the 2nd), and everything works correctly. But logging out and back in doesn't fix it - the issue returns when I log back in. I tried editing some articles in Firefox but I couldn't find any with the problem. The font size is different though, so nothing wraps the same exact way. —Keenan Pepper 21:03, 1 December 2019 (UTC) ## I was referred here: Wikimedia Foundation error My question is- what can I (or somebody at Wiki) do about the "Wikimedia Foundation error" problem I've been encountering on and off, since late November. Details are at: Wikipedia:Help_desk/Archives/2019_November_24#Wikimedia_Foundation_error,_relatively_recent_possible_parameter_change/adverse_effects Pi314m (talk) 03:18, 1 December 2019 (UTC) • update* The most recent attempt/failure as of this moment is: Wikimedia Foundation Error - Our servers are currently under maintenance or experiencing a technical problem. Please try again in a few minutes. See the error message at the bottom of this page for more information. If you report this error to the Wikimedia System Administrators, please include the details below. • Request from 64.24.9.40 via cp1087 frontend, Varnish XID 612331345 • Error: 503, Backend fetch failed at Sun, 01 Dec 2019 03:28:11 GMT Pi314m (talk) 03:31, 1 December 2019 (UTC) THERE may be a related item at Slowdown on WP (start-of-problem time frame seems related) Pi314m (talk) 22:36, 1 December 2019 (UTC) @Pi314m: Please post a link which names the section, don't use edit links, they will fail when the page is next archived. --Redrose64 🌹 (talk) 23:48, 1 December 2019 (UTC) done. Thanks. Pi314m (talk) 09:17, 2 December 2019 (UTC) ## Show Changes and Old Pages How exactly does Show Changes work when editing on old revision of a page? It seems to compare the old revision against the current revision, rather than the previous revision (relative to the old revision). That's rather counterintuitive, isn't it? The tooltip says Show the changes you made to the text, after all. Confused regards, GUYWAN ( t · c ) 14:22, 1 December 2019 (UTC) It always compares to the current revision. See phab:T37067 and phab:T31674 for old MediaWiki requests, User:Js/ajaxPreview#Extra features for a user script I haven't tried. PrimeHunter (talk) 15:41, 1 December 2019 (UTC) I see. Thanks for the info, PrimeHunter. GUYWAN ( t · c ) 19:13, 1 December 2019 (UTC) ## Admin access via the API? I'm writing some code which looks at user editing history, with an eye towards sockpuppet detection. So far, I've been working with publicly available data, but eventually will want to get at things like deleted contributions, and other information only available to admins. How does one get access to that via the API? -- RoySmith (talk) 14:33, 1 December 2019 (UTC) @RoySmith: That is part of the standard API (c.f. mw:API:Deletedrevisions) (e.g. see here). The access you have to the API depends on your session, and may be filtered if using a grant or botpasswords. — xaosflux Talk 14:40, 1 December 2019 (UTC) @Xaosflux: deletedrevisions gives you the deleted revisions for a page. I'm looking for the deleted contributions for a user, i.e. what Special:DeletedContributions/RoySmith-testing would give you -- RoySmith (talk) 02:53, 2 December 2019 (UTC) @RoySmith: Use mw:API:Alldeletedrevisions (e.g. yours (click MakeRequest)). — xaosflux Talk 03:04, 2 December 2019 (UTC) Ah, so in mwclient-land: deleted = site.get('query', list='alldeletedrevisions', adruser='RoySmith-testing')  which of course gets me: mwclient.errors.APIError: ('permissiondenied', "You don't have permission to view deleted comments.", ...  when executed as an anonymous client, which gets me right back to having to set up a bot account and get that account the required permissions. -- RoySmith (talk) 03:33, 2 December 2019 (UTC) @RoySmith: there is no need for a "bot account" to just make a query - you would have the exact same issue you are having right now - you didn't log in. Just like when using the WEBUI, with the API you have to logon, and get an authentication token for future requests. In the WEBUI this is a cookie and your browser handles it for you, in the API you have to handle it yourself. See mw:API:Login and all of its related topics. — xaosflux Talk 13:17, 2 December 2019 (UTC) My apologies, I explained that poorly. I'm looking for a way that will work with an automated process that's running in the tools environment, not as part of a session where I'm logged in. — Preceding unsigned comment added by RoySmith-Mobile (talkcontribs) 16:36, 1 December 2019 (UTC) it is the exact same API as for non-admins, just additional items that will return once you authenticate. Help:Creating a bot may be a good place to start learning. — xaosflux Talk 00:26, 2 December 2019 (UTC) Ah, OK, this is starting to make sense. Looks like what I'll want to do is create a bot account, and then get that bot admin rights. I'll never be making any edits, so I'm thinking maybe indef block it, as a precaution against accidental edits due to programming errors? I had associated bots with, "things that make edits", in my mind, which led me to think a bot wasn't what I wanted. I've got plenty of work I can do with the anonymous API access I'm using now, but at least now I know where this is heading. Thanks for the help. -- RoySmith (talk) 01:47, 2 December 2019 (UTC) "BotPasswords" is a somewhat misleading name --- the feature is in no way tied to bot accounts. * Pppery * it has begun... 01:51, 2 December 2019 (UTC) You don't need a "bot account" to use the api - just that many bots use the API and your question is really seems to be more of a "how do I learn about the API" type then a specific function call issue. — xaosflux Talk 02:05, 2 December 2019 (UTC) @RoySmith: also take a look at mw:API, WP:EXEMPTBOT and WP:BOTDICT#Bot flag. If your bot doesn't do any edits, and doesn't need access to higher limits (both admin privileges and advanced API options), then you likely you wouldn't even need a bot account. However, if you want the bot to have admin privileges, you'll need to comply with WP:ADMINBOT. Headbomb {t · c · p · b} 02:18, 2 December 2019 (UTC) ## archive.today Sorry if this has been raised before, but is archive.today actually working at the moment? I can't get https://archive.today/ or any of the links to work. This is a problem, because I have archived various cites with it.--♦IanMacM♦ (talk to me) 11:11, 2 December 2019 (UTC) It's working now, but seems to have had quite an extensive outage in the last 24 hours.--♦IanMacM♦ (talk to me) 11:28, 2 December 2019 (UTC) ## Cross-post notice: WMF Fundraising on en.wiki Seddon (WMF) (talk) 14:02, 2 December 2019 (UTC) ## Tech News: 2019-49 16:57, 2 December 2019 (UTC) ## Weird bytecount in page history Please see User:JIP's notes at Wikipedia:Help desk#Weird bytecount in page history - there are two consecutive edits in User talk:PaxEquilibrium, one adding a section on 30 November, the next one adding a reply on 2 December. The first one has apparent size of ZERO bytes (even though it obviously ADDED a section), the other one has size apparently equal the net change made by both edits together. Anybody able to explain the phenomenon? --CiaPan (talk) 21:37, 2 December 2019 (UTC) Even weirder, the API says the revisions have the same SHA1, which is impossible. Maybe something went wrong during the rename from Geolodus to Glades12? Suffusion of Yellow (talk) 21:52, 2 December 2019 (UTC) As you can see in the thread at HelpDesk, the effect was observed before the user's rename. --CiaPan (talk) 21:57, 2 December 2019 (UTC) Thanks, misread the timestamps. Suffusion of Yellow (talk) 22:00, 2 December 2019 (UTC) No need to study timestamps, just note that User:JIP uses the old name of the other User when referring at WP:HD to their edit. :) --CiaPan (talk) 22:16, 2 December 2019 (UTC) Well, it is well possible for two different packets of data to have the same hash value. It's just rare in random data and very hard to achieve intentionally - but not impossible. And if the Wiki software used the hash value as a key for indexing a database, then such two edits would be indistinguishable, and that would could explain why two revisions return the same page length, resulting in a ZERO increment... --CiaPan (talk) 22:12, 2 December 2019 (UTC) SHA1 is a 160-bit hash, so the probability of that is about 10-48. But, just checking anyway: $ curl -s 'https://en.wikipedia.org/w/index.php?title=User_talk:PaxEquilibrium&oldid=928894386&action=raw' |sha1sum
d2a13183ec9fd859a8cc10164f4e2fbf58fc2d00  -
$curl -s 'https://en.wikipedia.org/w/index.php?title=User_talk:PaxEquilibrium&oldid=928622565&action=raw' |sha1sum a7e7aad391df4fc2132413e730d9007d1927078f -$ curl -s 'https://en.wikipedia.org/w/index.php?title=User_talk:PaxEquilibrium&oldid=928364063&action=raw' |sha1sum
30c6157b4f443428196a56bfe1e06876a18a9dd0  -
The other revisions have the correct hash; just not Geolodus/Glades12's. Suffusion of Yellow (talk) 22:36, 2 December 2019 (UTC)
I do not discuss how small or how big the probability of collision is. I just pointed out it is greater than zero, hence the event is possible. --CiaPan (talk) 07:38, 3 December 2019 (UTC)
Infinite monkey theorem discusses how a "possible" event is in fact not going to happen, as Suffusion of Yellow accurately pointed out. Using the ordinary meaning of the word impossible, it is impossible for two different pages at Wikipedia to have the same hash. Johnuniq (talk) 09:47, 3 December 2019 (UTC)
@Johnuniq: Possibly monkey theorem discusses how it is impossible. And Internet demonstrates how it is possible: SHAttered, The Register, ZDNet; more at Google. The ordinary meaning of 'impossible' is not relevant if we talk about guaranteed uniqueness. Anyway, the whole question on im/possibility is not relevant to this discussion — as long as it is not proven the hash was erroneously calculated or erroneously assigned to one of the page revisions, the logs above ARE an example the collision is possible. And monkeys may go type Hamlet. --CiaPan (talk) 10:31, 3 December 2019 (UTC)

I confirmed Suffusion of Yellow's findings by checking that the most recent items in the history at User talk:PaxEquilibrium have the oldid values and sha1 hashes shown. The size of the downloaded file is shown in the following table.

timestamp oldid sha1 bytes
2019-12-02T09:51:18Z 928894386 d2a13183ec9fd859a8cc10164f4e2fbf58fc2d00 185,074
2019-11-28T16:22:52Z 928364063 30c6157b4f443428196a56bfe1e06876a18a9dd0 183,755

The history shows "09:51, 2 December 2019 ... (+1,319)". That byte difference is 185074 − 183755 = 1319.

The history for the above three items shows:

 09:51, 2 December 2019 JIP 185,074 bytes (+1,319) Archiving needed: reply to Geolodus 15:26, 30 November 2019 Glades12 183,755 bytes (0) Archiving needed: new section 16:22, 28 November 2019 JIP 183,755 bytes (+8) Thanks: added closing ...

Johnuniq (talk) 03:47, 3 December 2019 (UTC)

## Weird number of pages in a category

Please see User:JIP's notes at Wikipedia:Help desk#Weird bytecount in page history - Category:Online entertainment says its subcategory Category:Entertainment websites contains MINUS SIX pages!

Anybody able to explain....? --CiaPan (talk) 21:43, 2 December 2019 (UTC)

@CiaPan: "pages in a category" is notoriously unreliable (c.f. phab:T18036). — xaosflux Talk 01:10, 3 December 2019 (UTC)
@Xaosflux: I didn't know. Thank you for info. --CiaPan (talk) 07:44, 3 December 2019 (UTC)

## Equation \operatorname macros?

For writing ${\displaystyle \operatorname {E} [X]}$ is there a standard way to use \DeclareMathOperator or \newcommand to avoid typing \operatorname{E} all the time? Wqwt (talk) 22:10, 2 December 2019 (UTC)

@Wqwt: Even if you could, it would only be effective within the same [itex]...</math> tags. Each block is parsed separately, there's no way for state to be preserved between them. Easiest thing might be to copy it into your local clipboard, so you can "type" it repeatedly with just Ctrl+v. Or you can look into clipboard managers or macro tools for your local browser/OS... -- FeRDNYC (talk) 07:20, 3 December 2019 (UTC)
@FeRDNYC: I see. It seems MathJax on its own (for example used in math.stackexchange.com) supports it. Wqwt (talk) 20:01, 3 December 2019 (UTC)
@Wqwt: I secretly wish for some mechanism to add a standard header that gets added to the beginning of any [itex]...</math> blocks, possibly separate ones: one global, and then the ability to add per-page ones for unusual things. However, I have no idea how expensive such a feature would be, or even if it would make more sense for anything like this to be stricter and more behind the scenes. –Deacon Vorbis (carbon • videos) 20:31, 3 December 2019 (UTC)

## Difficulty connecting

A reader ticket:2019120210008574 is having difficulty connecting to Wikipedia. The message they received says: "You tried to connect wikipedia.org, but the server presented an expired certificate."

Normally, I'd ask them to visit this forum but by definition they cannot. Any thoughts?S Philbrick(Talk) 22:27, 2 December 2019 (UTC)

Sphilbrick, Possible that their computer's date is wrong? The cert expires 11/22/2020. SQLQuery me! 22:34, 2 December 2019 (UTC)
SQL, Interesting possibility; I'll check. S Philbrick(Talk) 00:55, 3 December 2019 (UTC)
Also, ask what their browser and browser version is, see if it is a "modern" browser. — xaosflux Talk 01:05, 3 December 2019 (UTC)

## Table display

I have had problems with the display of a table, and realise that it displays as intended when I'm logged out, but not when I'm logged in. The table is here and the rendering when I'm logged in is at File:Table logged in.jpg and when logged out is at File:Table logged out.jpg. Can anyone please explain what may be wrong with my settings to cause this? --David Biddulph (talk) 08:37, 3 December 2019 (UTC)

I am seeing the same thing as you, logged in and logged out. – Ammarpad (talk) 09:22, 3 December 2019 (UTC)
Looks like a problem with spanning – note how the middle row cells get into the separating space between the 'Host' column and the 'Final' group and between the 'Final' and the 'Third place play-off' group. --CiaPan (talk) 11:34, 3 December 2019 (UTC)
I tested available skins, but that didn't help. However, the problem seems to have something to do with testing gadget options – when I went to preferences/gadgets and unchecked the 'Make sure that headers of tables remain in view as long as the table is in view (requires Firefox v59 or Safari)' in the 'Testing and development' section, the problem disappeared (I'm using Google Chrome at the moment). I suppose this option is not available for logged-off users, hence logged-off can see the table correctly.
Try using a browser compatible with the option or try switching the option off. --CiaPan (talk) 11:50, 3 December 2019 (UTC)
I can confirm it's that option. If I turn it on, I see the malformed table (both on Chrome 78 and Firefox 70). The problem is that with the StickyTableHeaders gadget turned on, the table is split into a
 and
 element, which apparently causes the rowspan to break. I don't know if that's a bug in the rendering engine, or in the MediaWiki parser, or somewhere else, but it's certainly a bug. rchard2scout (talk) 12:02, 3 December 2019 (UTC)
So we can get rid of the problem by removing rowspan=4, or at least reducing it to rowspan=2, and filling rows 3. and 4. with empty cells (at the cost of displaying unnecessary cells' borders). --CiaPan (talk) 12:15, 3 December 2019 (UTC)
@David Biddulph, Ammarpad, and Rchard2scout: I implemented a fix described above, by truncating the gap fillers in the header area from 4 to 2 rows and adding 2-rows-high gap fillers in the data area: Special:Diff/929064299.
Please verify how it works in your browsers: Special:Permalink/929064299#Results of Nations League Finals. --CiaPan (talk) 12:36, 3 December 2019 (UTC)
I am using Chrome. Yeah, it's fixed. But I think the one by Jts1882 below is even better. I notice it eliminated the superfluous incomplete shading of the two empty demarcation columns. – Ammarpad (talk) 21:50, 3 December 2019 (UTC)
It's a known limitation in the gadget when there are header cells with rowspan. See MediaWiki talk:Gadget-StickyTableHeaders.css#Bug: rowspan in headers does not propagate into table. PrimeHunter (talk) 12:42, 3 December 2019 (UTC)
Besides the above, I've tweaked the table to make it a better simple data table. It's generally more interoperable and better represents what you are trying to display. --Izno (talk) 14:02, 3 December 2019 (UTC)
Following the suggestion in the bug report, just changing the rowspan header cell to a regular td cell gives the following:
Season Host Final Third place play-off Winner Score Runner-up 2018–19Details Portugal Portugal 1–0 Netherlands England 0–0 (a.e.t.)(6–5 p) Switzerland 2020–21Details TBD
This seems to work with the gadget. 14:11, 3 December 2019 (UTC)

## Consecutive edits merged by editor on history page

Is there a script (or option) to see consecutive edits by the same editor merged into a single entry in articles' history page? — Preceding unsigned comment added by Guarapiranga (talkcontribs) 22:46, 3 December 2019 (UTC)

Check out User:Alex Smotrov/histcomb. User has long since stopped editing, but it should be working. ~ Amory (utc) 02:17, 4 December 2019 (UTC)
Fantastic! Precisely what I wanted, Amorymeltzer. Here's my vote to make it a standard feature/gadget on preferences. Guarapiranga (talk) 04:15, 4 December 2019 (UTC)
No wonder I didn't know about it; it wasn't on WP:USL. Now it is. Guarapiranga (talk) 04:42, 4 December 2019 (UTC)

## 'Redirects from' template?

Is there a template (or magic word) that will return the name of the template a given template name redirects to? (e.g. {{redirects from|Brazil}} → BRA). Guarapiranga (talk) 05:23, 4 December 2019 (UTC)

Module:Redirect can do part of this, but I haven't found a template that does exactly what you need. {{#invoke:redirect|main|Template:Brazil}} → Template:BRA -- John of Reading (talk) 12:57, 4 December 2019 (UTC)
The problem here is that any given page can have more than one redirect - it's a many-to-one relationship, consider this list. Incidentally, BRA is not there because it is not a redirect but a dab page. --Redrose64 🌹 (talk) 18:08, 4 December 2019 (UTC)
Redrose64, what I'm looking for is the mapping in the opposite direction: what does a redirect page redirect to? From that list, it would, for instance, return Brazil when called over Republic of Brazil: {{redirects from|Republic of Brazil}} → Brazil. Guarapiranga (talk) 20:39, 4 December 2019 (UTC)
Thanks, John of Reading! Just created {{redirects from}} as a wrapper over it, to be used as an alias. I'm not sure it'll work for what I wanted—subst'ing country names with their ISO codes, without invoking Lua (which requires 2 subst's and always times out on long lists of countries)—but I'll try. Cheers. Guarapiranga (talk) 20:51, 4 December 2019 (UTC)

## Ill-formatted maintenance category

I discovered that Leeds is currently placed in the non-existent (and non-hidden) category Category:Articles with disputed statements from November 2,019. It seems like it came about from {{doubtful|date=November 2019}} (that is, I can remove the category by removing the templates), but I can't figure out why the output is formatted incorrectly. kennethaw88talk 08:52, 4 December 2019 (UTC)

Something in {{Infobox settlement}} is cleverly formatting numbers for the population_metro parameter (and some others). For example, if you edit the line to read |population_metro=2638127 and preview it, you will see the population shown as 2,638,127. That is, something inserts the commas. The category includes 2019 and the clever code is inserting commas in that as well. A quick looks suggests it is {{formatnum:{{{population_metro}}}}}. The doubtful tag probably should be in the population_metro_footnotes parameter. Johnuniq (talk) 09:22, 4 December 2019 (UTC)
Yes, use |population_metro_footnotes=. This matter is covered by the first bullet of Template:Infobox settlement#Usage, although not obviously so. --Redrose64 🌹 (talk) 18:05, 4 December 2019 (UTC)
Fixed it. I didn't really pay enough attention to where in the text the tag was being used, although I wouldn't have been able to figure out the formatnum code, anyway. Thanks. kennethaw88talk 20:36, 4 December 2019 (UTC)

## Diagnosing bad preview image on Page Preview card

When I hover on the link Statue of Liberty the preview image is File:USA New York City location map.svg, a generic map of New York City (which doesn't even have the location of the statue marked! The pin is overlaid in the infobox using some template magic). I think it would be much more appropriate to show an image of the statue itself. mw:Page Previews/Functionality#Article image: suggests that the "first image that appears in [the] infobox" should be chosen. However, in this case, the first image in the infobox is File:Lady Liberty under a blue sky (cropped).jpg. Is there some undocumented rule that images with very tall aspect ratios are ignored? Is this just a bug? Colin M (talk) 16:18, 4 December 2019 (UTC)

Is there some undocumented rule that images with very tall aspect ratios are ignored? Yes, actually, certain aspect ratios are ignored. You might try searching the archives to see what those are. --Izno (talk) 16:48, 4 December 2019 (UTC)
Resolved-ish
Oof, looks like it's actually worse than that. Candidate images are scored by some (fairly opaque, presumably subject-to-change-at-any-time) algorithm, and the highest-scoring image is used. The main infobox image on that page isn't so skinny that it's completely ruled out as a preview image, but its point boost for being the first image is less than the bonus the map gets for having a squarish aspect ratio. I've corrected the docs at mw:Page Previews/Functionality#Article image: for now. It would be nice if there were a way to give the algorithm a hint without changing the appearance of the article (short of globally blacklisting the unwanted image from previews), but I'm not holding my breath. Colin M (talk) 17:49, 4 December 2019 (UTC)
I am fairly certain there was a task in Phabricator to add a "hey, don't use that one" but a brief search yields little. --Izno (talk) 22:32, 4 December 2019 (UTC)

## Can this happen automatically or only manually?

At the top of this talk page edit, the revision time shows as "Revision as of 00:54, 31 October 2019”. But the time stamp in each edit segment of that edit shows as "00:30, 31 October 2019 (UTC)”. It looks like it was done manually by copying the preview of a draft done at 00:30 and pasting into an edit published at 00:54. I'm considering correcting the 00:30 time stamps to avoid confusion, but want to make sure there was no way this could have arisen automatically. Thoughts? Humanengr (talk) 18:26, 4 December 2019 (UTC)

none that I'm aware of, but I don't think you should change anyone else's text timestamps. The "actual" timestamp for anything we would care about is what is in the revision timestamp. This possibly came from an edit conflict, going back, copy-pasting like you suggested, etc. — xaosflux Talk 18:29, 4 December 2019 (UTC)
It looks like they just didn't know how to sign so they manually mimicked signatures. User talk:Samp4ngeles#Signing comments supports this. Just ignore it. PrimeHunter (talk) 21:56, 4 December 2019 (UTC)

## BLP noticeboard not search engine indexed, but many archives are

I noticed that, while WP:BLPN is not indexed on search engines (and to my mind, certainly shouldn't be), many of its archives are: [4]. Those often include discussion of potentially sensitive BLP matters. After a discussion with Xaosflux, it seems that, while the robots.txt exclusion file is set up properly, being transcluded or linked elsewhere still might lead search engines to crawl these, even when they're intended not to be. On Xaosflux' advice, I'd like to get a few opinions about the best way to handle this so that these will be reliably excluded from search engines, and I'm not fully conversant with exactly how Mediawiki handles that. Any expertise in that would be much appreciated. If there is a solution to ensure newly created archives are also not indexed, that would be even better. Seraphimblade Talk to me 19:14, 4 December 2019 (UTC)

• One difference is that for the archives our only directive not in use is in robots.txt, on the main page we are asserting a noindex on the page itself. — xaosflux Talk 19:24, 4 December 2019 (UTC)
The <meta name="robots" content="noindex,follow"/> directive is in the page source, due to the NOINDEX magic word in Wikipedia:Biographies of living persons/Noticeboard/Header. — xaosflux Talk 19:28, 4 December 2019 (UTC)
On archive pages of other boards such as WP:ANI the NOINDEX is in an archive box that is also present on the archive pages - so that is one way to do it. — xaosflux Talk 19:31, 4 December 2019 (UTC)
The archives currently don't have NOINDEX - no Category:Noindexed pages - and the entry on robots.txt is formatted in such a way that it won't cover subpages if my understanding of the syntax is correct. I dunno if the correct solution would be to edit MediaWiki:Robots.txt or a Phab level solution is needed (or a bot directed addition of NOINDEX to each archive). Jo-Jo Eumerus (talk) 19:30, 4 December 2019 (UTC)
We could easily have a bot add something to those pages for now, but getting the future archives to auto-have it like how ANI's do may be better. — xaosflux Talk 19:32, 4 December 2019 (UTC)
For what it's worth, ANI archives are NOINDEXed through Template:Administrators' noticeboard navbox all, which the archive bots add to each archive as they are directed by the {{{archiveheader}}} parameter in {{User:MiszaBot/config}}. So one way to do NOINDEX for all BLPN archives created in the future would be to append {{NOINDEX}} to the same parameter at WP:BLPN. Of course, one would have to update all the past archives as well. Jo-Jo Eumerus (talk) 19:53, 4 December 2019 (UTC)
That's an easy enough bot run if this will be the "fix". — xaosflux Talk 20:19, 4 December 2019 (UTC)
(also see note above) - robots.txt matching should be midstring greedy and match those pages - but if you see a specific syntax error with it please let me know! — xaosflux Talk 19:31, 4 December 2019 (UTC)
Many of the archives are indexed because of url variations with percent-encoding. For example, https://en.wikipedia.org/wiki/Wikipedia%3ABiographies_of_living_persons%2FNoticeboard%2FArchive165 is indexed by Google while the canonical url https://en.wikipedia.org/wiki/Wikipedia:Biographies_of_living_persons/Noticeboard/Archive165 is blocked by https://en.wikipedia.org/robots.txt. %3A instead of colon is covered by an extra entry in robots.txt but %2F instead of slash is not. I see five potential ways to fix or reduce such problems:
1. Add __NOINDEX__ to the wikitext, typically via a template adding {{NOINDEX}}. This will place noindex in the html of any url variation (except some external mirrors).
2. Add more url variations to robots.txt (or cut url's off before characters with url variations).
3. Find out where search engines see the url variations. If the origin is under our control then replace them with the canonical url's.
4. Get MediaWiki to automatically noindex non-canonical url's.
5. Get MediaWiki to automatically redirect non-canonical url's to the canonical url which is covered by robots.txt.
Option 4 and 5 would be Phabricator requests and cannot be done locally. PrimeHunter (talk) 01:04, 5 December 2019 (UTC)
are you confident about the %2F problem - it is hard to think it has never come up before? — xaosflux Talk 01:22, 5 December 2019 (UTC)
It came up at MediaWiki talk:Robots.txt#Google thinks it's cute, we need to blacklist Wikipedia%3AArticles_for_deletion%2F. I don't see another explanation. Consider Archive165 site:en.wikipedia.org. If I click the little green triangle and then "Cached" at the entry for "Wikipedia:Biographies of living persons/Noticeboard/Archive165" then I get "This is Google's cache of https://en.wikipedia.org/wiki/Wikipedia%3ABiographies_of_living_persons%2FNoticeboard%2FArchive165". If I do the same for "Wikipedia:Teahouse/Questions/Archive 164" (which is allowed by robots.txt) then I get "This is Google's cache of https://en.wikipedia.org/wiki/Wikipedia:Teahouse/Questions/Archive_164". https://de.wikipedia.org/robots.txt has some entries from de:MediaWiki:Robots.txt with all four combinations of %3A versus colon and %2F versus slash. PrimeHunter (talk) 02:00, 5 December 2019 (UTC)
thanks for the update.
• I've added the %2F version to the robots file, this will take a bit to propagate. I think the NOINDEX options are better for this use case though, if someone wants to get it fixed for future archives we can run a bot after the old ones very easily. — xaosflux Talk 03:35, 5 December 2019 (UTC)
If a bot's going to do that, then maybe it should NOINDEX all the Talk: archives of BLPs as well. There are probably tens of thousands of BLP talk pages with archives, and most are more poorly watched than BLP/N. Suffusion of Yellow (talk) 03:49, 5 December 2019 (UTC)
a bot run to put a future-standard template on ~200 pages is one thing, dealing with a huge number of talk pages is another - I'd be more supportive of a phab change to make "Talk namespace subpages" be NOINDEX by default. — xaosflux Talk 04:00, 5 December 2019 (UTC)
• I think this should fix it so far as future pages [5], though please check to make sure I didn't do anything dumb. If we can do the old pages by bot, hopefully that should take care of it? Seraphimblade Talk to me 05:04, 5 December 2019 (UTC)

## Whitelines before and after template

Why are there whitelines before and after the {{Schneersohn family tree}} template, see e.g. Schneersohn. Debresser (talk) 23:48, 4 December 2019 (UTC)

Well, it's happening because when there is no |align= specified, the template sets a style of margin: 1em auto;. Why, I do not yet know, but I'll look further at the history. —[AlanM1(talk)]— 00:20, 5 December 2019 (UTC)
At this edit, the behavior was changed so that, if |align= is not specified, the style margin: 1em auto; is set. Previously, it looks like the style was a margin of 0, which is typical for a navbox. The current version produces a 1em empty space above and below. I'll also note that it has a white background by default, instead of the usual purple-ish used for navboxes. I'm inclined to remove the margin style or put it back to being an unconditional 0, as it was before the edit. Also, I think the background color should default to that of other navboxes, as it's kind of ugly when the margin is removed IMO. I'm concerned that I don't have the time at the moment to research how it's used everywhere. Would someone more familiar with navboxes handle this and/or comment? —[AlanM1(talk)]— 00:45, 5 December 2019 (UTC)
Thank you for your comments. I removed the culprit.[6] Can somebody please make the edit to add the blue color, in line with other navboxes? Debresser (talk) 19:21, 5 December 2019 (UTC)

## Table totals and total percentages

Is there a way of making 2-step calculations in tables without running into node-count errors?

I've for instance fully automated this article, converting what previously were pasted numbers into the formulas that calculate them and pulling the input info from a single main source, but, for the life of me, can't figure out how to calculate percentages from totals without running into node-count errors. Best I could do was use a pasted running total onto the page and hide it in a span tag. I looked into doing that with subst, but couldn't figure out how. I stared at this code for half an hour, and couldn't see how it could help either. Guarapiranga (talk) 20:18, 5 December 2019 (UTC)


text:
zbMATH — the first resource for mathematics

Homogenization of parabolic equations with a continuum of space and time scales. (English) Zbl 1170.34037
The authors consider a linear parabolic equation in divergence form defined via a uniformly elliptic and symmetric matrix $$a$$, with the aim to give some numerical approximation of the solution. In spite of the title the paper is not a paper about some result in homogenization, but deals with numerical approximation of a fixed operator which is defined via a matrix whose coefficients $$a_{ij}$$ belong to $$L^{\infty}(\Omega)$$, $$\Omega \subset {\mathbb R}^n$$ (possibly oscillating and not regular).
The natural space in which a solution of the equation $$u_t-\text{div}(a\cdot\nabla u)=g$$, $$g\in L^2(\Omega\times (0,T))$$, with $$u=0$$ in $$\partial\Omega\times (0,T)$$ lives is $$\{u\in L^2(0,T; H^1_0(\Omega))\mid u_t\in L^2(0,T; H^{-1}(\Omega))\}$$.
The authors consider a change of variables, called caloric coordinates, defined as the solutions
\begin{alignedat}{2}{\partial_t F_i} - \text{div}(a\cdot\nabla F_i)&= 0 &\quad &\text{in }\Omega \times(0,T),\\ F_i&= x_i &\quad &\text{on }\partial\Omega\times(0,T),\\ \text{div}(a\cdot \nabla F_i)&= 0 &\quad &\text{in }\Omega\times\{0\},\end{alignedat} $$i=1,\dots n$$. The authors prove that, if $$\Omega$$ is convex and under some assumption on the trace of $$\langle a \cdot \nabla F, \nabla F \rangle$$, the function $$\tilde u := u \circ F^{-1}$$ belong to the space $${\mathcal Z}= \{v\in L^2(0,T; H^2(\Omega))\mid v_t\in L^2(0,T; L^2(\Omega)) \}$$ and give some estimate in this space depending (only) on the data. Defining finite dimensional spaces of functions of the type $$\varphi \circ F$$ the authors prove several results of convergence of the approximated solutions to the solution of the original problem.

MSC:
 34D10 Perturbations of ordinary differential equations 35B27 Homogenization in context of PDEs; PDEs in media with periodic structure 68P30 Coding and information theory (compaction, compression, models of communication, encoding schemes, etc.) (aspects in computer science) 60F05 Central limit and other weak theorems 35B05 Oscillation, zeros of solutions, mean value theorems, etc. in context of PDEs 35K20 Initial-boundary value problems for second-order parabolic equations 35A35 Theoretical approximation in context of PDEs
Full Text:

format: plain


text:
Journal of Prime Research in Mathematics

# Exact wiener indices of the strong product of graphs

K. Pattabiraman
Department of Mathematics, Faculty of Engineering and Technology, Annamalai University, Annamalainagar, India.

$$^{1}$$Corresponding Author: pramank@gmail.com

### Abstract

The Wiener index, denoted by $$W(G)$$, of a connected graph $$G$$ is the sum of all pairwise distances of vertices of the graph, that is, $$W(G) = \frac{1}{2} \sum_{u,v∈V (G)}d(u, v)$$. In this paper, we obtain the Wiener index of the strong product of a path and a cycle and strong product of two cycles.

#### Keywords:

Strong product, Wiener index


text:
# Routing in RORB

I’ve been reviewing some of the background that explains the way RORB works, particularly Appendix A in the RORB manual and the 1974 paper by Mein, Laurenson and McMahon Simple Nonlinear Model for Flood Estimation.

The key mathematical aspects of RORB are the continuity equation and a relationship between storage and discharge.

For any storage, the continuity equation can be written as: “inflow in a time period, minus outflow in that time period equals change in storage”.

Or as used in RORB:

$\frac{I_t+I_{t+1}}{2}-\frac{Q_t+Q_{t+1}}{2} = \frac{S_{t+1}-S_t}{\Delta t}$        (1)

Where $I$ is inflow, $Q$ is outflow, $S$ is storage and $\Delta t$ is the time step, $t$ is one time period and $t+1$ is the next time period.

The relationship between storage and discharge used in RORB is:

$S = kQ^m$        (2)

This is justified in Appendix A of the RORB manual and in Mein et al. (1974).

Substituting equation (2) into (1):

$\frac{I_t+I_{t+1}}{2} + \frac{Q_t+Q_{t+1}}{2} = \frac{kQ_{t+1}^m-kQ_t^m}{\Delta t}$        (3)

In the general case, we are solving for the outflow $Q_{t+1}$ and know all the other parameters i.e. the inflow ($I_t$ and $I_{t+1}$), the outflow at the previous time step $Q_t$, along with $m$ and $k$ which are properties of a catchment and/or a waterway.

Equation (3) can be rearranged as follows

$Q_t + Q_{t+1} - I_t - I_{t+1} + \frac{2k}{\Delta t} \left( Q_{t+1}^m-Q_t^m \right) = 0$        (4)

I’ve written that equation (4) is equal to zero, but this will only be the case if we have the correct value of $Q_{t+1}$.

This opens the possibility of a numerical solution; guess a value of $Q_{t+1}$ and plug it into equation (4), if that doesn’t equal zero,  guess again. In applied mathematics, this is referred to as root finding i.e. finding where a function equals zero. There are a number of procedures to do this efficiently (see for example, Numerical Recipes).

Let’s start with the Newton-Raphson procedure which the method discussed in Mein et al. (1974)

Think of equation (4) as a function of $Q_{t+1}$ i.e.

$f \left( Q_{t+1}\right) = Q_t + Q_{t+1} - I_t - I_{t+1} + \frac{2k}{\Delta t} \left( Q_{t+1}^m-Q_t^m \right)$      (5)

We guess a value of $Q_{t+1}$ say $Q_{t+1.1}$ and would like to calculate a better guess that brings $f \left( Q_{t+1}\right)$ closer to zero. Consider the derivative of $f \left( Q_{t+1}\right)$ at our initial guess, this is just the slope of the tangent at $Q_{t+1.1}$ as shown in the figure below which hits the axes at a point closer to the required root so would be a good next guess.  Call this point$Q_{t+1.2}$ .

The slope is rise/run so in this case.

$f' \left( Q_{t+1}\right) = \frac{ f \left( Q_{t+1}\right)}{Q_{t+1.1} - Q_{t+1.2}}$        (6)

Now, rearrange (6) to give an expression for $Q_{t+1.2}$

$Q_{t+1.2} = Q_{t+1.1} - \frac{f \left( Q_{t+1}\right)}{f' \left( Q_{t+1}\right)}$      (7)

Next we need the derivative of equation (5) with respect to $Q_{t+1}$

$f' = 1 + \frac{2km}{\Delta t}Q^{m-1}_{t+1}$       (8)

Using this approach to find Q_{t+1.2}, substitute (8) and (5) into (7) to give.

$Q_{t+1.2} = Q_{t+1.1} - \frac{\Delta t \left(Q_{t+1.1} + Q_t - I_{t+1} - I_t \right) +2k \left( Q^m_{t+1.1} - Q^m_t \right)}{\Delta t + 2kmQ^{m-1}_{t+1.1}}$      (9)

Equation (9) is the same as equation (8) in Mein et al. (1974).

The iterative solution proceeds as follows.

1. Select an initial value of $Q$ for the first timestep $Q _{t}$,
2. Guess $Q _{t+1.1}$ (Mein et al. use $(I_{t+1} + Q_t)/2$
3. Use equation (9) to calculate $Q_{t+1.2}$
4. Set $Q_{t+1.1} = Q_{t+1.2}$
5. Calculate a new $Q_{t+1.2}$
6. Repeat steps 3 to 5 until $Q_{t+1.2}$ has a similar value to $Q_{t+1.1}$ or, equivalently, until equation (4) does in fact equal zero (or is nearly equal to zero).
7. Go to the next timestep
8. Set $Q _{t}$ (current timestep) equal to  $Q_{t+1}$ (from the previous timestep)
9. Repeat steps 2 to 8 for all time steps

This sounds straightforward but there can be numerical issues.  The initial guess needs to be quite close to the answer or the next guess provided by equation (9) could be a negative flow.  Putting this back into equation (5) will cause an error because it requires raising a negative number to a fractional power. Another challenge is that the derivative (equation 8) is undefined when $Q^m_{t+1}$ is zero if $m < 1$.

When reading the RORB manual, section 2.2.5 there is a comment that: “The Regular Falsi convergence algorithm was used”.  There is a good description of this root finding approach in Wikipedia.  The upshot is that RORB does not use Newton-Raphson as was discussed in Mein et al. 1974.

In R, the uniroot function provides a reliable way of root finding without the numerical issues of the Newton-Raphson procedure. uniroot is based on a C function zeroin as documented here.

A simple routing function, in R, is below.

Routing <- function(Ihydrograph, k, m, T, dt = 1, plotit = TRUE, return.values = FALSE){

# Ihydrograph is a function that describes the inflow hydrograph
# k and m are the routing parameters
# dt is the time step

I <- rep(0, T+1) # Initialise input vector
Q <- rep(0, T+1) # Initialise output vector
S <- rep(0, T+1) # Initialise storage vector

I[1] <- Ihydrograph(1) # initialise inflow

# Continuity equation that we seek to set to zero to determine Q at the next time step

myF <- function(Qip1, Qi, Ii, Iip1, k, m, dt){

Qip1 + Qi - Iip1 - Ii + (2*k/dt)*(Qip1^m - Qi^m)

}

for(i in 1:100){
I[i+1] <- Ihydrograph(i+1)
Q[i+1] <- uniroot(myF, interval = c(0,10), Qi = Q[i], Ii = I[i], Iip1 = I[i+1], k, m, dt)\$root
S[i+1] <- k*Q[i+1]^m

}

if(plotit){
plot(I, type = 'l', col = 'blue', las = 1, ylab = 'flow', xlab = 'Time step') # Inflow hydrograph
lines(Q) # outflow hydrograph
legend('topright', legend = c('Inflow', 'Outflow'), lty = 1, col = c('blue', 'black'), bty = 'n' )
}

if(return.values) return(Q)

}

Let’s test it using a hydrograph as a function (see this blog for details).

What about the influence of k and m on routing?

Influence of the m parameter on routing

Influence of the k parameter on routing

RORB starts with a rainfall excess hyetograph (the rainfall that is left over after losses have been subtracted) and then routes this through a series of elements to produce flow at the catchment outlet.  Here I’ve modelled a single element but that gives an indication of how the program works.

Code for the routing function and to produce these figures (also available as a gist).

Code to produce these figures.
# Specify an inflow hydrograph as a function

my.Qmin <- 0
my.Qmax <- 1
my.beta <- 10
my.t.peak <- 20

Hydro <- function(tt, t.peak = 3, Qmin = 1, Qmax = 2, beta = 5) {
Qmin + (Qmax - Qmin)*( (tt/t.peak) * (exp(1 - tt/t.peak)))^beta

}
# Initialise the inflow
Ihydrograph <- function(tt){
Hydro(tt, t.peak = my.t.peak, Qmin = my.Qmin, Qmax = my.Qmax, beta = my.beta)
}

# Routing
Routing(Ihydrograph, k = 20, m = 1, T = 100, plotit = TRUE, return.values = FALSE)
# Step function hydrograph (or possibly based on measured inflows)

inflow <- c(0,0, 1,1,1,1,1, rep(0, times = 94))
Ihydrograph <- approxfun(1:101, inflow)
Routing(Ihydrograph, k = 20, m = 1, T = 100, plotit = TRUE, return.values = FALSE)

############################################
# Influence of m
# Initialise the inflow

my.Qmin = 0
my.Qmax = 1
my.beta = 10
my.t.peak = 20

Hydro <- function(tt, t.peak = 3, Qmin = 1, Qmax = 2, beta = 5) {
Qmin + (Qmax - Qmin)*( (tt/t.peak) * (exp(1 - tt/t.peak)))^beta

}
Ihydrograph <- function(tt){
Hydro(tt, t.peak = my.t.peak, Qmin = my.Qmin, Qmax = my.Qmax, beta = my.beta)
}

# Wrap Routing as a function of m

Routing_m <- function(m, Ihydrograph, k, T, dt = 1, plotit = TRUE, return.values = FALSE){
Routing(Ihydrograph, k, m, T, dt = 1, plotit = plotit, return.values = return.values )
}
m.seq <- seq(0.3, 1, 0.1)
x <- lapply(m.seq, FUN = Routing_m, Ihydrograph = Ihydrograph, k = 20, T = 100, dt = 1, plotit = FALSE, return.values = TRUE)
x1 <- do.call(cbind, x)

plot(Ihydrograph(1:100), type = 'l', col = 'blue', las = 1, ylab = 'flow', xlab = 'Time step') # Inflow hydrograph
matlines(x1)
legend('topright', legend = m.seq, col = 1:6, lty = 1:5, bty = 'n')

############################################
# Influence of k

# Wrap Routing as a function of k

Routing_k <- function(k, Ihydrograph, m, T, dt = 1, plotit = TRUE, return.values = FALSE){
Routing(Ihydrograph, k, m, T, dt = 1, plotit = plotit, return.values = return.values )
}
k.seq <- c(1, 5, 10, 15, 20, 50)
x <- lapply(k.seq, FUN = Routing_k, Ihydrograph = Ihydrograph, m = 0.8, T = 100, dt = 1, plotit = FALSE, return.values = TRUE)
x1 <- do.call(cbind, x)

plot(Ihydrograph(1:100), type = 'l', col = 'blue', las = 1, ylab = 'flow', xlab = 'Time step') # Inflow hydrograph
matlines(x1)
legend('topright', legend = k.seq, col = 1:6, lty = 1:5, bty = 'n' )

## One thought on “Routing in RORB”

1. Pingback: Routing in RORB – II | tonyladson


text:
# Question #6d237

Nov 22, 2016

$f \left(x\right) = 3 x - 1$ is one to one, and has the inverse ${f}^{- 1} \left(x\right) = \frac{x + 1}{3}$

#### Explanation:

A function $f$ is said to be one to one if for any ${x}_{0} , {x}_{1}$ in the domain of $f$, $f \left({x}_{0}\right) = f \left({x}_{1}\right)$ implies ${x}_{0} = {x}_{1}$. In other words, there is only one element in the domain of $f$ that maps to any given element in the range of $f$.

We will first show that $f \left(x\right) = 3 x - 1$ has this property. Suppose ${x}_{0}$ and ${x}_{1}$ are real numbers such that $f \left({x}_{0}\right) = f \left({x}_{1}\right)$. Then

$3 {x}_{0} - 1 = 3 {x}_{1} - 1$

$\implies 3 {x}_{0} = 3 {x}_{1}$

$\implies {x}_{0} = {x}_{1}$

Thus $f \left(x\right) = 3 x - 1$ is one to one.

As $f \left(x\right)$ is one to one, it has an inverse function ${f}^{- 1} \left(x\right)$ where ${f}^{- 1} \left(f \left(x\right)\right) = f \left({f}^{- 1} \left(x\right)\right) = x$.

One way of finding ${f}^{- 1}$ is to set $y = f \left(x\right) = 3 x - 1$, change all the $x$'s to $y$'s and vice versa, giving $x = f \left(y\right) = 3 y - 1$, and then solve for $y$. This results in an equation of the form $y = {f}^{- 1} \left(x\right)$.

Set $x = f \left(y\right) = 3 y - 1$

$\implies x + 1 = 3 y$

$\implies y = \frac{x + 1}{3} = {f}^{- 1} \left(x\right)$

Notice that given ${f}^{- 1} \left(x\right) = \frac{x + 1}{3}$ we have ${f}^{- 1} \left(f \left(x\right)\right) = f \left({f}^{- 1} \left(x\right)\right) = x$, as desired.


text:
# Which of the following values of an alternating voltage or current represents the real magnitude?

This question was previously asked in
SSC JE EE Previous Paper 11 (Held on: 24 March 2021 Morning)
View all SSC JE EE Papers >
1. RMS value
2. Peak value
3. Average value
4. Instantaneous value

Option 1 : RMS value
Free
CT 1: Basic Concepts
17847
10 Questions 10 Marks 6 Mins

## Detailed Solution

Considered a sinusoidal Alternating wave of voltage and current

From the waveform:

$$v = {V_m}\sin \left( {\omega t} \right)$$

And,

$$i = {I_m}\sin \left( {\omega t + ϕ } \right)$$

Where Vm and Iare the maximum value of instantaneous voltage and current respectively.

v, i is the instantaneous value of voltage and current at any instant t.

ω is the angular frequency in radian/second.

And, ω = 2πf

f is frequency in Hz.

Root-Mean-Square (RMS) Value:

• The RMS value of an alternating current is given by that steady (DC) current which when flowing through a given circuit for a given time produces the same heat as produced by the alternating current when flowing through the same circuit for the same time.
• It is also known as the effective or virtual value of the alternating current, the former term being used more extensively.
• RMS values of an alternating voltage or current represent the real magnitude.

RMS value of the alternating quantity is given as,

$$V_{RMS}=\frac{V_m}{\sqrt2}$$

$$I_{RMS}=\frac{I_m}{\sqrt2}$$

Average Value:

The average value of an alternating current is expressed by that steady current which transfers across any circuit the same charge as is transferred by that alternating current during the same time.

The average value of the alternating quantity is given as,

$$V_{avg}=\frac{2V_m}{\pi}$$

$$I_{avg}=\frac{2I_m}{\pi}$$