User talk:Jitse Niesen

Jitse Niesen

Current talk page

Archive 1, Archive 2

Thanks

Well, I'll try to make some edits (I am working on bijection), but watch my English - is faaaar from perfect :-(. Wojciech Świderski 03:38, 13 July 2008 (CDT)

Don't worry about your English. I think it's good enough, and if not, it will be corrected. I will watch the bijection article and see if I can improve on what you write. -- Jitse Niesen 16:18, 13 July 2008 (CDT)

Definition of a mathematical category

Thanks for the adjustment to the definition of a mathematical category. I'm working on an illustrated example. Peter Lyall Easthope 14:42, 13 July 2008 (CDT)

Wikimedia, copyright, etc.

Hi Jitse, when I needed a picture I always asked Stephen Ewen, but apparently he is on holiday, because he doesn't react to my messages. I like to have one picture of Hans Christian Oersted and perhaps two of James Clerk Maxwell. Wikimedia commons has plenty of those, but since I never bothered about copyright, I don't know if I can grab them. Do you know?--Paul Wormer 10:12, 4 August 2008 (CDT)

From your friendly neighbourhood mistress of ceremonies

I signed you in at The August Party Do join us on Wednesday September 2nd for what I hope will be a very active party with music, music, music. Theme: "My Favourite Band" (or, 'ensemble' or 'group' or 'orchestra' or 'singer' or 'recording' or...? Aleta Curry 23:28, 7 August 2008 (CDT)

Proposals results

Hi. Some months ago two proposals were presented, one concerning an "Internationalisation sandbox" [1] and another about translation of approved articles [2]. I went to the Proposals main page and to its associated subpages to find the result of those proposals (it says that they were assigned to the Executive Committee), but nothing. Is it possible that I missed the page were the results of those proposals were posted or they still haven't been analysed by the Executive Committee? --José Leonardo Andrade 13:15, 16 August 2008 (CDT)

These proposals have not yet been discussed by the Executive Council. I don't know what's happening. Your best chance is to ask the proposal driver (Pierre-Alain Gouanvic and Jens Mildner, respectively). I'm supposed to check that the proposals do not get stuck but I'm afraid I have been slack recently. -- Jitse Niesen 07:10, 18 August 2008 (CDT)

Thank you for the information. The drivers of those proposals haven't been particularly active on Citizendium lately, I've checked their contributions. It worries me that it takes so long to make a decision, the proposal looses momentum and perhaps even people loose interest. I'll see if I can contact those users. --José Leonardo Andrade 13:31, 18 August 2008 (CDT)

Link to an image

Jitse, in the bibliography of the Rene Descartes article I tried to add a link to the scan Descartes_Geometrie_matieres.png but the link is not visible. Please tell me what is wrong. Thanks, Peter Lyall Easthope 17:21, 1 September 2008 (CDT)

Hi Peter. I had a look and the link was visible, so I'm not sure what you mean. Perhaps you intended to include the actual image in the article? If so, you need to use Image: instead of Media:. Have a look at the edit I did just now (diff). If that's not what you want, then just revert my edit. Cheers, Jitse Niesen 04:39, 4 September 2008 (CDT)

jn>"I had a look and the link was visible, ..."
Yes, the link was visible but led to an empty page! The link should anchor to the image.

jn>"If that's not what you want, ..."
Its ok for me but I would expect others to prefer that the title be a link anchored to the image.

jn>"... then just revert my edit."
I tried it. Not satisfactory as explained above.

In any case, the image is now visible. Thanks, Peter Lyall Easthope 19:45, 10 September 2008 (CDT)

Discussion page for Category Th. article

There is also an issue on the discussion page for the Category Th. article. ...Peter Lyall Easthope 19:50, 10 September 2008 (CDT)

I finally got around to replying. This has proved to be a rather busy month. I copied your question from Talk:Category theory/Related Articles to Talk:Category theory. I think it's best not to use talk pages of subpages; it's just too easy to lose discussions and questions that way. -- Jitse Niesen 06:10, 21 September 2008 (CDT)

diff(approved, draft)

Jitse, there should be a one-click diff of a draft from the approved article. An editor needs to see quickly any suggested improvement and a contributor should also see the differences. Perhaps this exists and I haven't found it. Thanks, Peter Lyall Easthope 10:08, 29 September 2008 (CDT)

Yes, there should be. I believe there even used to be a button for that, but it stopped working after a software update. I'll think about it. -- Jitse Niesen 09:32, 30 September 2008 (CDT)

Correct, there used to be such a button. I don't know what changed but that method no longer works. I have not seen any other way of doing it, except the obvious and laborious cut/paste/compare route. Chris Day 09:35, 30 September 2008 (CDT)

P.S. I'll track down the old method and show you how it was done. Possibly that will give you a clue to a fix. And thanks for the {{localurl: idea. It works prefectly. Chris Day 09:39, 30 September 2008 (CDT)

Naming proposals for wars

Is the proposal process indeed the right format when I do not have a specific recommendation? In other words, I want to get some consensus on this, or at least the acceptance that the originator can come up with the name he or she thinks is most appropriate, and it's an accepted procedure that other names can be used, but they will become redirects in the interest of efficiency.

This is something that could and should be a matter for a group of Military Workgroup editors, but, as far as I know, I'm the only one. There have been several examples of problems: I referred to a U.S. operation by its code name, in the all-caps format that the U.S. uses, and got an enormous number of complaints. There was much arguing about whether Vietnam War was proper going back to 1959, 1954, 1945, 1937, or earlier.

There is merit to spending time on the argument if there are serious questions about the time periods, and if they should have different names. In cleaning up what was an impossibly large Vietnam War article, I kept that as a main article but spawned links to a number of somewhat arbitrary subarticles.

In other words, let's either have a policy, or accept the first author's working title (unless it is offensive) and put in redirects for every other proposal. Howard C. Berkowitz 17:38, 1 October 2008 (CDT)

The proposal process is not for brainstorming. You must have a reasonable definite proposal in your head before you start (or you may have two possibilities in your head), but not just a vague idea. If you have only a vague idea, then it's probably best if you conduct a couple of discussions first and that should give you an idea on what's the best.

The rule "originator chooses name" is a definite proposal, so you could try that. Whether it will be accepted is of course another thing. It seems to be in contradiction with CZ:Naming Conventions.

If something concerns only the Military Workgroup, and you're the only editor, then I think you can do whatever you like. The all-caps format is possibly an example of this. Just start a style guide for military articles, and write that U.S. code names should be all-caps. I can understand that many will dislike it, but I think within your discretion, as long as you're the only editor. Listen to the arguments, give them serious consideration, but in the end, the editors of the Military Workgroup decide. The only body who can overrule you is the Editorial Council, and if there are enough opponents they will probably petition it. Of course, it's another matter whether it's wise to do something that may alienate other authors and that may be overturned (personally, I think all-caps is odd, but I haven't followed the discussion and if this is the convention in the military and academics studying the military, that's a very strong argument).

The Vietnam War is rightly is also in the History Workgroup, so you will have to work with history editors on the scope of our article Vietnam War. -- Jitse Niesen 14:43, 14 October 2008 (UTC)

It's a little worrisome that I am the only active editor for Military. I did start a draft of a style guide for Computers on the Workgroup page. Is that, in general, where such should go, or perhaps a subpage (or equivalent) of the main workgroup page?

I'll propose some rules, once I know where to put them. I do have some specific things in mind, more where there are several ways to do it and I have no preference, and others where something is needed but I don't know what it is. In other words, for the latter two, I actively want discussion.

Objections to the all-caps conventions (and I have never said it should be used for everything) have been strong "I don't like it", as opposed to "the reason for not doing is..." For example, if I put Operation Barbarossa in all caps, someone could quite properly correct me because the WWII Germans did not use all caps. The current British do not, which is why Operation Granby (they didn't have sub-operations) goes with DESERT STORM/SHIELD/SABRE. It's a judgment call to use the English "operation" rather than the German "Aktion". Perhaps there should be a redirect of "Aktion Barbarossa". Howard C. Berkowitz 15:06, 14 October 2008 (UTC)

I can well imagine that it worries you to be the only active editor. Some guidance for style guides can be found in CZ:Proposals/Create workgroup style guides. It points to CZ:Chemistry style guide as an example. I think David E. Volk is the person to ask questions about workgroup style guides. As long as the style guide for the Computer Workgroup is very short, you can keep it on the main workgroup page, but once it grows a bit (which will surely happen), it's probably better to put it on a page by itself. -- Jitse Niesen 13:53, 22 October 2008 (UTC)

Belated Happy B'day!

Many happy returns of the day! Supten Sarbadhikari 00:26, 13 October 2008 (UTC)

Admissibility of an Article

I am interested to know whether an article about my grandfather's marine engine business would be admissible. Easthopes were the most numerous small marine engines on the west coast of Canada during the first half of the twentieth century. An article on Vivian Marine Engine Works is also possible. Vivian built larger diesel engines used in tugboats, ferries, small freighters and other workboats.

I've had a brief look for rules of admissibility and not found any.

Thanks, Peter Lyall Easthope 16:49, 27 October 2008 (UTC)

If the motors were fairly widely used in a broad area, sure, why not? Go for it! Hayford Peirce 17:10, 27 October 2008 (UTC)

I agree. For future reference, the rules are in CZ:Maintainability, but it is not clear (at least to me) how to apply them. -- Jitse Niesen 12:40, 28 October 2008 (UTC)

Next step for disambiguation proposal

Hi, I'm trying to figure out what the next step is for my disambiguation proposal. I gather that I need to make a resolution in the EC that it be adopted - is that correct? Thanks... J. Noel Chiappa 14:37, 28 October 2008 (UTC)

That's correct. I believe you're a member of the Council yourself, so you can propose the resolution yourself. -- Jitse Niesen 12:20, 29 October 2008 (UTC)

Yes, nice feature, that! ;-) I'll go read up on the resolution stuff, and put one in the queue. Thanks! J. Noel Chiappa 13:30, 29 October 2008 (UTC)

About Logarithm

Jitse, I am thinking of adding another section to Logarithm entitled "Numerical examples". It would include an example of multiplication of two numbers (say 135.683 times 2.5787) and an example of finding a cube root (say of 738.532). I realize that calculators are used for that now ... but I still think that the article should include examples to show how such calculations were done before we had calculators. Do you think that such a section would enhance the article? Please let me know. Milton Beychok 19:13, 28 October 2008 (UTC)

I think it would make a very nice addition. You could also write a bit about slide rules. At the moment, the article doesn't really explain why we should care about logarithms. -- Jitse Niesen 12:33, 29 October 2008 (UTC)

Thanks for your comments, Jitse. However, a Mathematics editor (named Dimitrii Kouznetzov) has now re-written the lead-in section and re-located the graph without any discussion or rationale on the Talk page. The net result is that the lead-in section which was easily understood before is now way above my head. Too much higher mathematics terminology. So I have decided to bow out rather than do any further work on the article. Milton Beychok 23:42, 30 October 2008 (UTC)

I'm looking at it. -- Jitse Niesen 13:06, 31 October 2008 (UTC)

Milton, that's exactly when people like yourself should be commenting. If you, an informed scientist, don't understand it what chance do others have? I'd argue that while editors are great for checking accuracy they are not so great a judging the correct level for a lay reader. I admit I have the same failings in biology. Chris Day 13:11, 31 October 2008 (UTC)

I agree very much with Chris's comment. Milton, you can be useful in flagging things that are too complicated. As you may have seen, I also agree that the introduction that Dimitrii wrote is at too high a level. As for moving the graph, surely that can be discussed? My own opinion is that this is only a small detail. -- Jitse Niesen 14:00, 31 October 2008 (UTC)

Chris and Jitse, I will take your words to heart. Next time, I won't "give up" so easily. Thanks, Milton Beychok 15:49, 31 October 2008 (UTC)

Categories

Thanks for the follow up on Dmitrii's page. Now I think about it do we have a CZ: page on categories? I don't recall seeing one. If not I might take that section from Dmitrii's talk page and rework it into a short FAQ section on categories at citizendium. Chris Day 13:13, 31 October 2008 (UTC)

The only thing I know of is CZ:Article Mechanics Complete#Categories, which is hard to find and I think my explanation is a bit better. Oh, and there is also a paragraph at the pages about how we differ from WP: CZ:Introduction to CZ for Wikipedians and CZ:How to convert Wikipedia articles to Citizendium articles. -- Jitse Niesen 14:00, 31 October 2008 (UTC)

I'll try and collate it. Chris Day 14:24, 31 October 2008 (UTC)

Sinus en cosinus

Hallo Jitse, ik heb dit geschreven: sine and cosine. Ik heb geprobeerd dit op VWO niveau te schrijven. Maar voor mij is VWO bijna 50 jaar geleden (of eigenlijk bestond het toen nog niet) en ik bezit ook geen VWO boek(en). Met andere woorden, ik heb de didaktiek zelf verzonnen. Mijn plan is om dit in het stuk van Dmitrii te schuiven, maar voordat ik dat doe wil ik graag dat iemand anders er naar kijkt. Zou jij dat willen doen? Als je geen tijd hebt zal ik het Milton vragen. Groetjes, --Paul Wormer 15:56, 3 November 2008 (UTC)

Dat is inderdaad hoe ik het zou doen. Eerst via een rechthoekige driehoek en dan via de cirkel. Op details heb ik wel wat opmerkingen. Ik zou in het tweede stukje geen vectoren gebruiken, maar alles uitdrukken in de coördinaten van een punt op de cirkel. En ik denk dat je bij het bewijs van de somformules een beetje te snel bent in hoe rotaties m.b.v. de (co)sinus uitgedrukt kunnen worden. Maar het is beter geschikt voor een algemene encyclopedie dan de tegenwoordige versie (ik heb de aanpak in het huidige artikel trouwens wel eens eerder gezien). -- Jitse Niesen 16:36, 3 November 2008 (UTC)

Jitse, ik heb het bewijs van de somformules uitgebreid, kan je nog 's kijken? Ik zou niet goed weten hoe ik dat bewijs zonder (eenheids)vectoren zou moeten doen, dus ik heb in de definitie voorlopig ook de vectoren maar laten staan. Misschien kan je iets specifieker uitleggen waarom je daar geen vectoren maar punten wil? Je (d.w.z. men) moet natuurlijk hoeken definieren, dus minimaal moet je lijnsegmenten invoeren, en het verschil met vectoren wordt dan nog slechts een kwestie van semantiek.--Paul Wormer 14:18, 4 November 2008 (UTC)

Ik heb inmiddels mijn meetkundige stuk in sine ingevoegd. Dus als je commentaar wil geven (of nog beter, zelf dingen wil veranderen) dan kijk s.v.p. naar sine. --Paul Wormer 10:23, 7 November 2008 (UTC)

Your testimony

Please let us have it! --Larry Sanger 21:05, 3 November 2008 (UTC)

Driver

Hi Jitse, good to see you active again. I have signed up as driver for two of the proposals. What is the next step on my behalf? I think we might want to get some more feedback on the proposals since they have been sitting a while and there are new people here now. I can then clean them up with to refelct the community input.

A third one I am driving, the subgroup proposal, is pretty much ready to go for a vote (that one is currently in the new proposal section. Chris Day 22:59, 23 February 2009 (UTC)

CZ Governance

Hi Jitse, thanks for restarting the proposals. But before I sign up as a driver again, I'd just like to know whether the CZ governance is dead or not. As a member of the Executive Committee you should know whether there's activity or not. It's just that I don't see any point in driving a proposal that's never decided upon. Jens Mildner 21:16, 24 February 2009 (UTC)

Advice on numerical problem needed

Hi Jitse, David Volk started Vector rotation and based himself on a paper in J. Graph. Tools (see Talk:Vector rotation#Paper on internet for a link to the full text of the paper). It seems to me that the paper contains an oddity/flaw, see talk page. Could you have a look at it and give your considered opinion? Thanks, --Paul Wormer 01:09, 9 April 2009 (UTC)

Bot for category creation?

Hi Jitse, do you see a simple way to implement a bot script to create all those categories at Special:WantedCategories? --Daniel Mietchen 07:56, 28 April 2009 (UTC)

I did this before, see User talk:Jitse Niesen/Archive 2#Bot request. I just need to know what text there should go on the category pages. If you could give me a list like: "For [[Category:XXX tag]], use the same text as Category:Mathematics tag" then I can do the rest. Alternatively, I can create the category page without any text. -- Jitse Niesen 10:56, 28 April 2009 (UTC)

I have no idea about proper formatting of category pages, just saw that Meg Ireland does it all by hand, which I imagine to be a pain. I told him about your offer but haven't seen a reaction. --Daniel Mietchen 22:13, 1 May 2009 (UTC)

More on bots - what about bot support for approval process?

Hi Jitse, please take a look at http://forum.citizendium.org/index.php/topic,2666.0.html and if you see ways to make the process technically simpler (e.g. by means of a bot or of supplementary name spaces), please let us know. Thanks! --Daniel Mietchen 08:24, 13 May 2009 (UTC)

mathematics approval

Could you have a look at the free statistical software article? Howard Berkowitz nominated it for approval as a computers editor, but we could use a mathematician as well. Thanks much! Joe (Approvals Manager) 18:53, 24 May 2009 (UTC)

I wrote a quick note on the talk page. -- Jitse Niesen 07:41, 30 May 2009 (UTC)

Thanks, Jitse. The article is now officially approved by Howard only, but we recently set a precedent for approving articles after the fact. When you get home and have had a chance to recover from your travels, please go to the metadata template and add your name below Howard's in the "approved' section at the very bottom. Then leave a note on the Approvals Manager talk page and I'll add an appropriate notice to the approval subpage. --Joe (Approvals Manager) 18:32, 30 May 2009 (UTC)

Rotation matrix

Jitse, I wrote a article on the rotation matrix. Its final part contains an almost trivial derivation of eq. (1) of T. Möller and J. F. Hughes (the article that David Volk dug up). I believe that this equation is the quickest way to build a rotation matrix from two vectors. I gave an alternative formula for the case that the equation breaks down. I believe that my alternative formula is a little faster than the Householder formula that David gave in Vector rotation. In doing this derivation I was breaking a CZ rule: I did it myself, I have never seen the equation elsewhere, although anybody, who would sit down for it, could derive it as an exercise.

I'm quite interested in your comments, since so far you always managed to find some (luckily so far non-disastrous) errors in my work. --Paul Wormer 11:40, 27 May 2009 (UTC)

I'm travelling at the moment, so it's a bit hard to find the time. You will probably have to wait till when I return to England in a week's time. -- Jitse Niesen 07:41, 30 May 2009 (UTC)

an additional remark

Jitse, the following remark does not fit on Talk:Aleph-0:
I did not choose "countable set" or "aleph-0" because it is my main interest, or a priority. When I happened to find Citizendium I immediately tripped over some poor articles, incomplete or even mistaken. That is why I registered. It is pure chance that I started with "neighbourhood" and "countable", but one leads to another, and rewriting "countable" made me look on sleph-0, somehow forced me to rewrite aleph-0 (and to start continuum hypothesis) in order to put some system in the topic. Peter Schmitt 00:19, 20 June 2009 (UTC)

Complex number page

The Complex number page still contains what I consider to be a blatant error: "In other words, up to a scaling factor, division by z is just complex conjugation." I think this would be correct if it said, "In other words, up to a scaling factor, division by z is just multiplication by the complex conjugate of z" or if it said "In other words, up to a scaling factor, taking the reciprocal of z is just complex conjugation"; but as it stands (according to the only reasonable interpretation I can see) it's equating two operations which in general involve completely different changes to the angle on the complex plane. As you know, this problem was pointed out on a Wikipedia discussion page in 2007. As a math editor, would you please either ask a constable to correct just this one sentence in the current article, or arrange to have the draft approved? (I haven't looked at the latest draft; I'm just concerned about this particular error.) Thanks. Catherine Woodgold 15:28, 11 July 2009 (UTC)

The formulation may be unfortunate, but it is correct. The "scaling factor" is 1/|z|^2, a real number, and the angles (the argument) of the conjugate and the inverse are the same. Probably it would be better to write "In other words, up to the scaling factor 1/|z|^2, division by z is just complex conjugation." I don't know if in such a case approved version can be corrected. Peter Schmitt 22:07, 11 July 2009 (UTC)

Why don't the two of you, and possibly anyone else you can rope in, work out an *exact* replacement phrase and then put it into this discussion area. If all of you agree that it should replace the Approved version, either I'll change it myself or I'll ask Matt what he things about it. Hayford Peirce 22:30, 11 July 2009 (UTC)

My suggestion:

In other words, up to the scaling factor ${\frac {1}{\left|z\right|^{2}}}$ (a real number), division by z is just complex conjugation.

(Unfortunately, the fraction looks awful in text.) Peter Schmitt 22:57, 11 July 2009 (UTC)

If we use our current approval (and re-approval) rules: since Peter is a mathematics editor, I would suggest that Peter refrain from making any changes to the article and let Jitse or Catherine make the change on the Draft. Then (assuming Peter agrees with the change), he can can re-nominate the draft for approval using the single editor process (since he has not made any content edits to the article)... HELLO CATHERINE! :)

Check with the User:Approvals Manager (Joe) if you want to be sure. D. Matt Innis 23:21, 11 July 2009 (UTC)

Matt's suggestions sound v. feasible to me. Hayford Peirce 23:36, 11 July 2009 (UTC)

As far as I see, the draft differs much from the approved version (a direct comparison seems to be difficult). I thought there is a possibility to edit such things without (re)approval? This is not a correction but only a clarification, and certainly not a change of content. (By the way, I think something is wrong - much too difficult -- if an editor is disqualified to make an approval even after such cosmetic edits. Even some minor edits should be allowed. I think it is simply cheating if suggesting a change is allowed, but doing the same edit is not.) Peter Schmitt 23:41, 11 July 2009 (UTC)

I have put a link on the Approval Manager talk page. Peter Schmitt 23:49, 11 July 2009 (UTC)

I looked at the draft and the approved version, they are completely different on this point. Somebody made some drastic changes. Further, I would say division of c by z is multiplication of c by the complex conjugate of z (and division by the modulus square of modulus of z). In the polar representation of complex numbers the issue is completely trivial, as we will all agree. It is $1/(re^{a})=e^{-a}/r$, which holds for all real and complex $a$. --Paul Wormer 08:09, 12 July 2009 (UTC)

"and division by the square of the modulus". Yes, this would avoid the displayed fraction. Peter Schmitt 09:53, 12 July 2009 (UTC)

If we want to spell it out completely, then with $z=r\exp(i\theta )\;$

$c/z=c/(r\exp(i\theta ))=(c/r)\exp(-i\theta )=(c/r^{2})\;r\exp(-i\theta )=(c/r^{2})\;{\overline {z}}\;$,

--Paul Wormer 11:13, 12 July 2009 (UTC)

It seems that you are saying that replacing the approved version with the draft would add more errors than it would fix. Your choices then would be to 1) fix the errors and use either the individual editor approval or three editor approval method to change the approved version or 2) revert the draft version to the version you like, then make the change that Catherine and Peter are looking to make and then use the individual or three editor approval methods as above. Does anyone see any other choices.

The idea of the approval rules is to make us work together to come up with the most accurate article possible while, at the same time, allowing the article to remain stable while we do. Hopefully, this reduces the workload on our experts. The errors in the draft are an example of why we want to have an approved version that is difficult to change - without editorial input. Changing our rules for something like this that can be managed within the same rules seems only a means to weaken them. However, it is possible, but would require community input from all the workgroups to consider all the ramifications of such a change.

D. Matt Innis 12:33, 12 July 2009 (UTC)