Wikipedia:Articles for deletion/Digon


 * The following discussion is an archived debate of the proposed deletion of the article below. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review).  No further edits should be made to this page.

The result was keep. (non-admin closure)  Onel 5969  TT me 16:22, 24 December 2015 (UTC)

Digon

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This article had the history of Degenerate polygon before it was moved on January 13, 2015 by Double sharp to Improper regular polygon and then by Steelpillow on September 6, 2015 to Degenerate polygon. It is now redundant to there. GeoffreyT2000 (talk) 23:17, 10 December 2015 (UTC)
 * Note: This debate has been included in the list of Mathematics-related deletion discussions. Shawn in Montreal (talk) 04:25, 11 December 2015 (UTC)
 * Comment I am no longer completely sure about merging monogons and digons, as the latter are far more legitimate - they make sense as abstract polytopes. The monogon does not as it has two 1-sections that are not line segments. (It doesn't have any 1-polytopes as elements, for a 1-polytope must have two endpoints - a 0-sphere - and the single "edge" of the monogon has but one.) It seems like they may be better separated. Double sharp (talk) 07:35, 11 December 2015 (UTC)
 * Strong keep - and comment: It is actually the degenerate polygon article that should be AfD-ed. That article fails WP:NOTABILITY - there is no mathematical literature devoted to the degeneracy of polygons, it is just a rag-bag of cases which get passing mention in the literature. For the same reason, wikipedia doesn't have articles on degenerate graphs or degenerate elephants either. On the other hand the digon itself is most useful when it is not degenerate, such as in spherical geometry, graph theory, abstract polytope theory, etc. and its properties are discussed in sufficient depth in sufficient sources to establish its notability. &mdash; Cheers, Steelpillow (Talk) 11:02, 11 December 2015 (UTC)

 Relisted to generate a more thorough discussion and clearer consensus.
 * Strong keep for the reasons spelled out by Steelpillow; a digon emphatically is an important geometric shape in non-euclidean geometries, and seemingly also in other fields I'm less familiar with. -Bryanrutherford0 (talk) 03:27, 13 December 2015 (UTC)

Please add new comments below this notice. Thanks, North America1000 13:38, 17 December 2015 (UTC)
 * Speedy keep -- a moment's web searching confirms that "digon" is a term frequently used in the mathematical literature, with a specific meaning that is separate from some general conception of degenerate polygons. Degenerate polygon smushed this, and the monogon into a single article in a way that did not improve the coverage of either. Accordingly, I have also rescued monogon, and made degenerate polygon into a redirect to a subsection of degeneracy (mathematics), where any specifics that are not already covered by monogon or digon can be mentioned. -- The Anome (talk) 14:26, 20 December 2015 (UTC)
 * Keep. Digon is a standard term in geometry for a line segment with multiplicity two.  This way, one gets all cyclic groups as rotation symmetries of polygons.  I've also seen digon used to refer to a lune of the sphere, but I think that is probably best kept completely separate.   S ławomir  Biały  14:39, 20 December 2015 (UTC) Although, I am sorely tempted to vote delete, for the sake of using the pun: "Let digons be bygones."
 * Comment:' yes, I've seen that too. I've created digon (disambiguation) to deal with that, and added otheruses to the top of the digon article. -- The Anome (talk) 14:46, 20 December 2015 (UTC)
 * The spherical lune is in fact an example of a regular digon: Coxeter provides a rock-solid reference in Regular Polytopes. The two articles need to acknowledge each other, as their subjects overlap although they are distinct (not all digons are lunes, while treating the circular lune as an irregular digon would not be sensible). &mdash; Cheers, Steelpillow (Talk) 15:16, 20 December 2015 (UTC)
 * To add to that, digon (disambiguation) is therefore misconceived and should be deleted. &mdash; Cheers, Steelpillow (Talk) 15:25, 20 December 2015 (UTC)
 * P.S. The digon has also been called the "bigon" in our culture's habitual mashing up of Latin prefixes with Greek suffixes. That has pretty much fallen out of use nowadays so we can truly say "let bigons be byegons" without fear of deletion. &mdash; Cheers, Steelpillow (Talk) 15:21, 20 December 2015 (UTC)
 * Keep or Merge - It might be merged and redirected into Lune_(geometry), although you might also argue the spherical lune section be merged here, and focus the lune article on the 2D cases. Mathworld splits into 2 article Lune and SphericalLune, and a third "degenerate" digon. Tom Ruen (talk) 15:58, 20 December 2015 (UTC)
 * Comment: it should definitely not be merged into the lune article, as that's only one special case of a digon. There are two concepts here: the abstract concept of a digon, without regard to being embedded in any space, which needs its own standalone article, and one possible realization of a digon, embedded within a spherical surface, which should be mentioned in both the digon and lune articles. -- The Anome (talk) 13:08, 21 December 2015 (UTC)


 * The above discussion is preserved as an archive of the debate. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review). No further edits should be made to this page.