Talk:Q172937

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Autodescription — polyhedron (Q172937)

description: solid in three dimensions with flat faces
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Classification of the class polyhedron (Q172937)  View with Reasonator View with SQID
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polyhedron⟩ on wikidata tree visualisation (external tool)(depth=1)
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Mathematical definition?

[edit]

This page does not agree with the definition commonly used in the mathematical community, where there is no requirement on the dimension.

Look for example at Ziegler's book "Lectures on polytopes", where "polyhedron" is defined as "H-polyhedron" and "V-polyhedron", and then it is shown that these actually are two descriptions of the same term. A "polytope" then is the bounded variant of a "polyhedron".

Is there some way for me to proceed here? Can I just change this entry? It is similarly "wrong" in wikipedia. Lmkastner (talk) 14:44, 29 November 2022 (UTC)[reply]

You can describe this in detail in any Wikipedia article you want. But here it is quite defined entity (specifically, 3D) and better not to change it. The matter of (English or other) label and description is secondary and not so relevant. So if you insist, you can change label/description accordingly. --Infovarius (talk) 07:52, 30 November 2022 (UTC)[reply]
I haven't yet decided, how to resolve this. In general the idea is to add links to wikidata for the the data formats of polymake (and later other computer algebra systems). In general, do you think it make sense to open a Project chat page? 158.181.76.206 11:01, 2 December 2022 (UTC)[reply]
Sorry, forgot to log in. Lmkastner (talk) 11:02, 2 December 2022 (UTC)[reply]
There are Q172937 and Q747980, please say what problem do you see between them? "polymake", whatever it is, seem to be narrow use of quite general notion... P.S. More useful would be to discuss at Wikidata:WikiProject Mathematics than general chat. --Infovarius (talk) 23:03, 3 December 2022 (UTC)[reply]
There are several different definitions of polyhedron, depending on the field. We should leave the existing items polyhedron (Q172937) and polytope (Q747980) with the definitions they currently have. I made a new polyhedron (Q115693864) item for polyhedron in any number of dimensions. For bounded polyhedra, use convex polytope (Q4129097). — The Erinaceous One 🦔 09:07, 14 December 2022 (UTC)[reply]
What's the difference of polyhedron (Q115693864) from polytope (Q747980) (or convex polytope (Q4129097))? --Infovarius (talk) 22:52, 15 December 2022 (UTC)[reply]
A polyhedron (Q115693864) can be unbounded whereas a convex polytope (Q4129097) must be bounded. For instance, a half-space (Q644719) is a polyhedron (Q115693864) but not a convex polytope (Q4129097).
polytope (Q747980) is the most general and includes any shape with flat sides, such as a square, cube, or star (which is not convex).
Examples of polytope (Q747980).
It's not clear whether disconnected shapes are considered a polytope (Q747980). — The Erinaceous One 🦔 02:26, 16 December 2022 (UTC)[reply]
So polyhedron (Q115693864) should be convex? And polytope (Q747980) can be unbounded? --Infovarius (talk) 20:37, 17 December 2022 (UTC)[reply]
Yes, that's right. — The Erinaceous One 🦔 21:06, 18 December 2022 (UTC)[reply]