Property talk:P4020

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ISQ dimension
property of an observable physical quantity being a product of the ISQ base quantities (length, mass, time, etc.)

Represents	quantity dimension (Q19110), International System of Quantities (Q16203461)
Has quality	observer (Q28973077), symbol (Q80071)
Data type	Mathematical expression
Domain	According to this template: physical quantity (Q107715) According to statements in the property: individual quantity (Q71550118) When possible, data should only be stored as statements
Allowed values	L^aM^bT^cI^dΘ^eN^fJ^g (note: this should be moved to the property statements)
Example	entropy (Q45003) → ${\mathsf {L}}^{2}{\mathsf {M}}{\mathsf {T}}^{-2}{\mathsf {\Theta }}^{-1}$ world population (Q11188) → $1$ torque (Q48103) → ${\mathsf {L}}^{2}{\mathsf {M}}{\mathsf {T}}^{-2}$
Tracking: usage	Category:Pages using Wikidata property P4020 (Q106836046)
Lists	Items with the most statements of this property Count of items by number of statements (chart) Items with the most statements Items with the fewest statements Count of items by number of sitelinks (chart) Items with the most sitelinks Items with the most sitelinks, but no link to one Wikipedia (sample: Welsh Wikipedia, cywiki) Items with the fewest sitelinks Most linked wikis Items with the most identifier properties Items with no other statements Most recently created items Items with novalue claims Items with unknown value claims Usage history (total) Usage history (main statement) Chart by item creation date Database reports/Constraint violations/P4020 Map Random list
Proposal discussion	Proposal discussion
Current uses	Total 1,970 Main statement 1,967 99.8% of uses Qualifier 3 0.2% of uses

[create Create a translatable help page (preferably in English) for this property to be included here]

Type “individual quantity (Q71550118)”: item must contain property “instance of (P31), subclass of (P279)” with classes “individual quantity (Q71550118)” or their subclasses (defined using subclass of (P279)). (Help)

Exceptions are possible as rare values may exist. Exceptions can be specified using exception to constraint (P2303).
List of violations of this constraint: Database reports/Constraint violations/P4020#Type Q71550118, SPARQL

Scope is as main value (Q54828448): the property must be used by specified way only (Help)

List of violations of this constraint: Database reports/Constraint violations/P4020#Scope, hourly updated report, SPARQL

Single value: this property generally contains a single value. (Help)

Exceptions are possible as rare values may exist. Exceptions can be specified using exception to constraint (P2303).
List of violations of this constraint: Database reports/Constraint violations/P4020#Single value, SPARQL

Allowed entity types are Wikibase item (Q29934200): the property may only be used on a certain entity type (Help)

Exceptions are possible as rare values may exist. Exceptions can be specified using exception to constraint (P2303).
List of violations of this constraint: Database reports/Constraint violations/P4020#Entity types

This property is being used by: en:Template:Infobox physical quantity sl:Predloga:Infopolje Fizikalna količina bh:टेम्पलेट:Infobox physical quantity ml:ഫലകം:Infobox physical quantity eu:Txantiloi:Magnitude infotaula be-tarask:Шаблён:Фізычная велічыня Please notify projects that use this property before big changes (renaming, deletion, merge with another property, etc.)

Font style: should be Roman (upright), not italics

The font style should be Roman (upright), not italics. That is the seven symbols: LMTIΘNJ. For example torque (Q48103),

not ${\displaystyle L^{2}MT^{-2}}$

but ${{\mathsf {L}}^{2}{\mathsf {M}}{\mathsf {T}}^{-2}}$

The seven symbols are not those of a physical quantity (Q107715) (which generally are in italics), but of a quantity dimension (Q19110). See also Wikidata:Property proposal/dimension. -DePiep (talk) 09:56, 11 January 2018 (UTC)

This a reference that supports DePiep's comment - in particular the dimension symbols specifically should be "symbolically represented by a single sans serif roman capital letter". Since this property has a "mathematical expression" value the default representation is in the italic form. I believe the underlying "mathematical expression" display just uses LaTeX (or the mediawiki version of it) to handle things, so do we want to replace these values with something that presents them consistently according to the BIPM recommendation in upright sans serif? I'm not even sure how you do that in LaTeX. ArthurPSmith (talk) 20:13, 18 January 2018 (UTC)

Ah - I fixed DePiep's example - the letters could be coded as {\mathsf X}. Do we want to apply this generally? ArthurPSmith (talk) 20:18, 18 January 2018 (UTC)

Why at all do you question my request while you yourself provided an extra source for it? What at all is wrong with this WD attitude? Really. I still have to meet a normal discussion here. -DePiep (talk) 01:09, 19 January 2018 (UTC)

The choice of LaTeX vs string data type seems to be inconsistent in general. With the same argument all quantity symbol (string) (P416) should use italic font. Apart from italic font I also do not know how to make subscripts for things like $\varepsilon _{\mathrm {r} }$ relative permittivity (Q4027242). I have seen some photometric quantities using [1] but can things like $\varepsilon _{\mathrm {r} }$ also be done with unicode letters? apparently yes: 𝜀ᵣ but depending on the font settings the result looks wrong. Also: Why apply mathsf to each letter seperately? I would simply write ${\mathsf {L^{2}MT^{-2}}}$.Ok, I forgot that it also affects the exponents.--Debenben (talk) 15:18, 22 January 2018 (UTC)

• Why has this not been fixed? - DePiep (talk) 23:29, 1 April 2018 (UTC)
  • @DePiep: and what is the proposed solution for that problem? Is it some changes in MediaWiki LaTeX extension, use \mathsf in this property in every case or switching this property datatype from mathematical expression to string? Wostr (talk) 00:43, 2 April 2018 (UTC)

@Wostr: Someone change the LaTeX code. In the OP here I did a demo, but I am not familiar enough with editing this in the property. - DePiep (talk) 09:56, 2 April 2018 (UTC)

Hmm, but the Artur's proposition to use \mathsf is that someone should manually change this property in every item and add \mathsf, am I right ArthurPSmith? Maybe it is possible to do it using a regexp and file a bot request for this? And of course use Wikidata usage instructions (P2559) in this property to indicate that \mathsf should be used in every case. Wostr (talk) 13:59, 2 April 2018 (UTC)

I fixed all values by using \mathsf. Toni 001 (talk) 14:08, 19 December 2019 (UTC)

Relative values

wikidata says this field is mandatory... what should I enter in case of relative properties, like noise figure (usually expressed in decibels) or total harmonic distortion (usually expressed in percentage) -? Retired electrician (talk) 07:14, 13 February 2023 (UTC)