Talk:Cis (mathematics)

History

 * Moved from List of trigonometric identities revision 2008-03-18T23:47:50 to here: https://en.wikipedia.org/w/index.php?title=List_of_trigonometric_identities&type=revision&diff=199204017&oldid=198448876
 * Move discussion: http://en.wikipedia.org/wiki/Talk:List_of_trigonometric_identities/Archive_1#New_section:_why_.22cis.22.3F
 * Most of the material was originally added to List of trigonometric identities by User:Michael Hardy with these edits:
 * 2006-11-22T01:14:47: http://en.wikipedia.org/w/index.php?title=List_of_trigonometric_identities&type=revision&diff=89339147&oldid=89334117
 * 2003-03-10T01:36:16 http://en.wikipedia.org/w/index.php?title=List_of_trigonometric_identities&type=revision&diff=735718&oldid=735712

Change back to a redirect
I'd prefer the article was changed back to a redirect rather than completely deleted. I agree it reads like someone's essay. At the very minimum a good citation needs to be found to make it anyway worth keeping the content. Dmcq (talk) 10:15, 6 January 2016 (UTC)
 * I have added a citation and some more history. Andrew D. (talk) 18:36, 8 January 2016 (UTC)
 * Too little to justify an article - they could go into Euler's function. And the whole of the rest is just just someone's own thoughts not a summary of secondary sources - it is an essay or original research. Dmcq (talk) 15:12, 9 January 2016 (UTC)
 * I agree, this should be a redirect to the Euler formula. There is nothing of substance this page adds and the notation is not in common use (I know of places where it is used, but it really shouldn't, as it is redundant to e^ix). Euler formula page could have a comment that cis is a rarely used and commonly deprecated notation. The "advantages" (Mathematical identities) aren't really any advantages but mere re-statements of the corresponding formulas for the exponential function. Having a standardised mathematical language is a blessing and having this this article stand on its own puts too much weight onto a notation that most mathematicians disapprove of. --Hxe8w5Lu01puY 01:46, 21 March 2016 (UTC) — Preceding unsigned comment added by Hxe8w5Lu01puY (talk • contribs)


 * I too think a redirect makes sense. The mathematical content is covered elsewhere; the other content is unsourced opinion (the history) or OR/trivia (the various examples of usage). Better to keep the mathematics in one place and eliminate the non-encylopaedic content.-- JohnBlackburne wordsdeeds 02:02, 21 March 2016 (UTC)

Reminded of it by the post below, and with no objections above, I have gone ahead and turned it into a redirect. Euler's formula mentions cis in the lead, and the mathematical content is covered in the article, so there is nothing to merge that I can see.-- JohnBlackburne wordsdeeds 01:01, 18 April 2016 (UTC)


 * No objections, huh? There are clearly objections against deleting the article, but they don't need to be repeated all over again as this has been discussed at length previously already. There is no consensus to delete the article, and although you were trying to suggest otherwise you clearly know about that, since your previous (meanwhile three!  ) attempts to get the article deleted all resulted in that it should not be deleted. This thread was finished and superseded by your deletion discussion (which you initiated on 2016-01-09) and it is meanwhile completely outdated (the article was in a much weaker state back then, with much less contents and without the reliable references it has now, and still there was no consensus to delete it). This thread should have been marked as closed when the deletion discussion was closed on 2016-01-17.


 * IMO, trying to get rid of an article about a notable topic three times in a row indicates that someone is following a personal agenda. Actively trying to suppress information not liked for what reasons ever is pushing a POV rather than maintaining neutrality as is required here. I find such behaviour annoying and it is wasting the time and energy of contributing editors.


 * While the cis function and Euler's formula are related, they are both notable topics by themselves, and covering both in a single article would only confuse readers (of course, there should be cross-links between the two articles). The interesting history of the cis function would be out of scope in the Euler article, just as the history of Euler's formula is not in the scope of the cis article. Also, they are typically used in different contexts.


 * You may not personally like or use the cis function, but others did and continue to do so when they find it convenient. The fact that it exists (and for some 150 years!) and is notable (as is established by more than enough sources - and more could be given) is already enough to warrant the article. As previous discussions have shown there are readers who do want to learn about cis specifically.
 * Further, in Wikipedia we have an obligation to describe things from a neutral point of view and without bias, so issuing suggestions to use one expression and not another is inappropriate.
 * --Matthiaspaul (talk) 19:01, 24 April 2016 (UTC)


 * We had one deletion discussion, started because someone objected to the PROD. But the outcome was no consensus, with the closer commenting that there was no clear ("not so much") consensus about whether to keep, merge or redirect. So the discussion over that was started here. Three editors supported redirecting, and after the discussion had been up for three months and stale for over a month with no-one objecting I [re]created the redirect. Even with you now objecting there is still consensus here that it should be a redirect.-- JohnBlackburne wordsdeeds 10:28, 28 April 2016 (UTC)

Deprecation notice
I think the use of CIS should be discouraged. Clearly, this is my personal point of view, but I do also think the majority agrees. As long the article has not been changed back to a redirect yet (see above), the deprecation should somehow be stated in the text. I am very open for suggestions that are not expressions of personal opinion. --Hxe8w5Lu01puY 22:48, 17 April 2016 (UTC) — Preceding unsigned comment added by Hxe8w5Lu01puY (talk • contribs)
 * I removed your statement for three reasons:
 * a) It does not maintain a neutral point of view and pushes a personal opinion. I am not aware of any authority who would have "declared" cis as "deprecated", so your assertion was likely not true. In either case, it was unsourced, and you will have to provide a reliable source if you want it to be considered for inclusion.
 * b) Even when reworded, such kind of information does not really belong into a lede. If true, it should be discussed further below, and the article already covers the fact, that it is not in mainstream use, so you were unnecessarily adding redundant information.
 * c) It was badly formatted (but if the other two reasons would not exist, this would be fixable, and you can be sure I would have fixed it for you).


 * As pointed out already, in Wikipedia we have an obligation to describe things from a neutral point of view and without bias, so recommending one expression over another (as is implied by terms like "deprecated") is inappropriate.
 * To give you an example, it is okay to state that cis is not in mainsteam use - nobody would seriously argue about that. It is, however, not okay to state, that it would be deprecated, as this implies that it should not be used. Who are we to push this down on our readers? This would not be a neutral statement, but an expression of a particular point of view, and as such it generally has no place in Wikipedia. There's one exception: If you find a reliable source actually stating that cis is deprecated by some named authority, we could add exactly that by citing that authority. However, I doubt, you will find a reliable source for this, because I have already made some efforts trying to find such authorative statements (in either direction). Quite in contrast to this, others have pointed out that cis is sometimes used as a convenient "vehicle" in math education in school. Further, I know for a fact, that cis is also taught in some engineering courses (not math!) at university (as a sometimes convenient abbreviation). This still does not indicate mainstream use (but we don't claim this in the article), but it indicates, that it isn't deprecated, so we can't include such a statement.
 * I hope this helps you understand some of our working principles at Wikipedia and why your assertion must be removed.
 * --Matthiaspaul (talk) 19:45, 24 April 2016 (UTC)

cjs function for electrical and computer engineers who already use i for a current function?
The i symbol is used in electrical engineering mathematics to represent a current, so it is standard to use j instead of i to represent sqrt(-1).

I can't seem to find (google search) any discussion comparing the words "cjs" and "cis" in the context of complex number trig. Does anyone except me use a cjs(theta) function?

Unrelated tangent discussion:

In my field, we also mix (radians + degrees) as a parameter for the sin function. (no, I'm not suggesting sjn function). Therefore, it is important for the cjs function to accept dimension-bearing parameters in any planar angle unit (e.g. (50 kiloturns), (1000 rpm * 1 hour)). AnotherNeko (talk) 10:45, 1 December 2022 (UTC)