Property talk:P7235
Documentation
any symbol used in the defining formula (P2534)
List of violations of this constraint: Database reports/Constraint violations/P7235#Item P2534, SPARQL
List of violations of this constraint: Database reports/Constraint violations/P7235#Scope, SPARQL
List of violations of this constraint: Database reports/Constraint violations/P7235#Entity types
List of violations of this constraint: Database reports/Constraint violations/P7235#allowed qualifiers, SPARQL
List of violations of this constraint: Database reports/Constraint violations/P7235#mandatory qualifier, SPARQL
Relationship to has-part
[edit]From the propoerty creation discussion:
- To bo honest, I do not really understand the proposal. How does it compare to the has part annotations that are used for example in https://www.wikidata.org/wiki/Q35875?--Physikerwelt (talk) 17:29, 3 June 2019 (UTC)
- I'm not sure. Use of has part(s) (P527) on items with defining formula (P2534) seems pretty random. There are currently 97 items on [1]: they don't appear to be structured. It might work on one or the other item when reading the statement 1-by-1 and knowing in advance what to look for. Also, the proposal might not be suitable for every item about physics. --- Jura 11:30, 6 June 2019 (UTC)
- It is still uncelar to me. Should I abandon using has-part Annotations Like in https://www.wikidata.org/wiki/Q35875 I think the has-part form is easyer to query and will be availible for annotations in Wikipedia soon https://phabricator.wikimedia.org/T208758. --Physikerwelt (talk) 13:17, 1 September 2019 (UTC)
Label
[edit]Using 'symbol' in labels is a better option. When I first saw this property, I didn't know what it was about. Wostr (talk) 14:27, 26 April 2020 (UTC)
- Support I also like more "symbol in defining formula". One might argue that "short is good", but in this case clarity might help. Toni 001 (talk) 18:14, 26 April 2020 (UTC)
- I don't think the property is meaningful without defining formula (P2534), especially, it shouldn't be used without a P2534 being present.
- At some point we should be able to do a complex constraint that ensures the value of this property is present in P2534 (e.g. "words" at Q91798342#Q91798342$8ae98ac0-4309-6712-81f7-74c4b584cb1b in Q91798342#P2534).
- If there are no parts of P2534-values that aren't covered by the proposed change, please go ahead. --- Jura 07:51, 27 April 2020 (UTC)
- e.g. at Poisson's ratio (Q190453) we need to make sure that this property isn't confused with quantity symbol (LaTeX) (P7973) also present there. --- Jura 08:00, 27 April 2020 (UTC)
- Yes. For new users we could state somewhere prominently that:
- quantity symbol (LaTeX) (P7973) contains any symbol typically used for a given quantity
- in defining formula (P7235) contains exactly one symbol, namely, the one used in the defining formula (P2534)
- (This should be clear from the current label and description, but new users could miss this fine distinction.) Toni 001 (talk) 09:43, 27 April 2020 (UTC)
- I added some usage instructions. Toni 001 (talk) 09:55, 27 April 2020 (UTC)
- I wouldn't really count on people reading that. It was meant for a feature that was never implemented. In the meantime, property descriptions can be used. For properties, there is a risk that people already don't read that. --- Jura 05:38, 28 April 2020 (UTC)
- Thanks for the hint about the non-implemented feature. I had noticed the mention of it in the description of Wikidata usage instructions (P2559) and was wondering what it meant. (By the way, I'm not too worried about "people not reading the instructions". This might happen for some casual user passing by, but once they start seriously contributing they'll need and find that information and be happy that it's there.) Toni 001 (talk) 08:42, 28 April 2020 (UTC)
- I wouldn't really count on people reading that. It was meant for a feature that was never implemented. In the meantime, property descriptions can be used. For properties, there is a risk that people already don't read that. --- Jura 05:38, 28 April 2020 (UTC)
- I added some usage instructions. Toni 001 (talk) 09:55, 27 April 2020 (UTC)
- Yes. For new users we could state somewhere prominently that:
Tighter constraints and symbol represents (P9758)-migration
[edit]I've been migrating the explanation of variables according to https://www.wikidata.org/wiki/Property_talk:P2534#How_to_explain_variables over the past weeks. While there is still a lot to do, I took the liberty of tightening the constraints on this property (in defining formula (P7235)) so that finding cases which need a migration can more easily be discovered and other editors be nudged into the right direction. Toni 001 (talk) 08:50, 8 September 2021 (UTC)
- It seems you changed some that can actually use "calculated from". Please clean up the incorrect changes. --- Jura 10:18, 7 November 2021 (UTC)
- There's been a long discussion before the creation of symbol represents (P9758), with the intent to move away from both "has part" and "calculated from". Please do not undo that work. Toni 001 (talk) 10:33, 7 November 2021 (UTC)
- Apparently that was proposed for cases where "calculated from" isn't possible and there is no consensus to undo our work with "calculated from". --- Jura 10:50, 7 November 2021 (UTC)
- The motivation for symbol represents (P9758) was to unify the different ways in which formula variables are explained. Toni 001 (talk) 18:08, 7 November 2021 (UTC)
- Apparently that was proposed for cases where "calculated from" isn't possible and there is no consensus to undo our work with "calculated from". --- Jura 10:50, 7 November 2021 (UTC)
- There's been a long discussion before the creation of symbol represents (P9758), with the intent to move away from both "has part" and "calculated from". Please do not undo that work. Toni 001 (talk) 10:33, 7 November 2021 (UTC)
- As @Infovarius: mentioned in the discussion, this moves the main information from statement values to qualifiers. I agree with him that this doesn't make much sense or at least seems counterintuitive. Maybe the new "P9758" could be used as main value in cases where "calculated from" isn't possible (labeled, e.g. "composed from"). This could solve the problems with "part of" while mostly maintaining the structure we built before.
- The approach attempted at Q604008#P7235 would mean that Wikidata would drop its usual way of modeling merely because of the presence of a defining formula.
- Similar we wouldn't re-organize an item around sub-images because someone added a image (P18) to it.
- Alternatives could be to host the defining formulas in separate items (either on Wikidata itself or elsewhere), given the technical problems around the datatype don't seem to be resolved. Commons now allows to annotate images directly.
- @Arbnos: you didn't comment on either aspect in the discussion. Would you be ok with the use of "calculated from" and P9758 as main value? --- Jura 14:26, 7 November 2021 (UTC)
Inverse : when a math property has a distinct item, and the object it is about its own
[edit]Notified participants of WikiProject Mathematics
In the example Jensen's inequality (Q518131) I think it’s OK to link to the kind of function it is true for real-valued function of a real variable (Q3075263) with has quality Search
The statement would be a perfect place to link the variable described … however
in defining formula (P7235) ⟨ f ⟩
this is not enough to not trigger the constraint that a formula must have a symbol for the object defined.
What could we do ? author TomT0m / talk page 16:36, 12 March 2022 (UTC)
- The variables should be explained on the same item on which the formula is stated. Toni 001 (talk) 10:05, 13 March 2022 (UTC)
- @Toni 001 That’s my point, actually, there is no way right now to explain the variable in the formula item. author TomT0m / talk page 19:22, 15 March 2022 (UTC)
- I'm not sure I follow: The item with the formula is Jensen's inequality (Q518131), and it could have a statement like this:
- Jensen's inequality (Q518131)in defining formula (P7235)f
symbol represents (P9758)convex function (Q319913) - Side note: I find the use of has characteristic (P1552) problematic, at least from the examples I've seen so far. It seems to be used in ways which would be better handled by a dedicated (and properly discussed) property. Toni 001 (talk) 08:39, 16 March 2022 (UTC)
- @Toni 001 That’s my point, actually, there is no way right now to explain the variable in the formula item. author TomT0m / talk page 19:22, 15 March 2022 (UTC)
What about a qualifier to express the origin of the symbol?
[edit]In statements about the symbols used in a formula, we so far express what they stand for, via symbol represents (P9758). We could also express where the symbol comes from, e.g. the in the in defining formula (P7235) statement for chemical affinity (Q382783) is derived from Μ (Q9902) and B (Q9705). Is this something we should be doing? If so, is there some recommended way of doing it? Thanks for any pointers. Daniel Mietchen (talk) 11:43, 7 September 2023 (UTC)