Wikidata:Property proposal/euler characteristic
Euler characteristic edit
Originally proposed at Wikidata:Property proposal/Natural science
| Description | topological invariant of a space |
|---|---|
| Represents | Euler characteristic (Q852973) |
| Data type | Quantity |
| Domain | topological space (Q179899) |
| Allowed values | natural numbers |
| Allowed units | none (unitless) |
| Example 1 | sphere (Q12507) → 2 |
| Example 2 | small stellated dodecahedron (Q1234054) → -6 |
| Example 3 | torus (Q12510) → 0 |
| Example 4 | real projective plane (Q633815) → 1 |
Motivation edit
I wanted to start entering into wikidata examples of manifolds and their properties (dimension, euler characteristic etc.) it seems that although for elementary particles for instance there are many properties one can enter into an item (electric charge / spin quantum number etc...) there are none of those for manifolds. I think it would be nice if apart from just the definitions related to manifolds wikidata would have some collection of examples with some of their very basic properties listed.Ptypicalht2 (talk) 18:21, 7 January 2019 (UTC)
Discussion edit
Comment @Ptypicalht2: can you try to add a few samples, datatype and a property description? If you are not sure how to format it, just a free text, someone might reformat it afterwards. If the proposal remains empty, it's unlikely to be created. --- Jura 10:56, 27 January 2019 (UTC)- I have fleshed out the proposal a bit. − Pintoch (talk) 09:18, 3 February 2019 (UTC)
Support ArthurPSmith (talk) 16:09, 4 February 2019 (UTC)
@Ptypicalht2, ArthurPSmith, Pintoch, Jura1: 
Done: Euler characteristic (P6438). − Pintoch (talk) 16:57, 4 February 2019 (UTC)