Property talk:P8751

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die axis
measurement of a coin that describes how the obverse and reverse dies were aligned to each other when it was struck, either in degrees (0-360) or hours (12-11)

Represents	coin orientation (Q5141550)
Data type	Quantity
Domain	coin (Q41207)
Allowed values	0 ≤ 𝓧 ≤ 360
Allowed units	clock position (Q5134807) or degree (Q28390)
Example	Musée Saint-Raymond, 2000 15 129 (Q29401431) → 12 clock position Musée Saint-Raymond, 2000 14 51 (Q28822821) → 3 clock position
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 Minimum and maximum Items with highest numeric value Items with lowest numeric value Database reports/Constraint violations/P8751 Map Random list
Proposal discussion	Proposal discussion
Current uses	Total 2,834 Main statement 2,832 >99.9% of uses Qualifier 2 <0.1% of uses

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

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/P8751#Single value, SPARQL

Citation needed: the property must have at least one reference (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/P8751#citation needed

Range from “0” to “360”: values should be in the range from “0” to “360”. (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/P8751#Range

Units: “clock position (Q5134807), degree (Q28390)”: value unit must be one of listed. (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/P8751#Units

Scope is as main value (Q54828448): the property must be used by specified way only (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/P8751#Scope, 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/P8751#Entity types

Type “coin (Q41207)”: item must contain property “instance of (P31)” with classes “coin (Q41207)” 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/P8751#Type Q41207, SPARQL

Question about die axis unit

@ Christelle Molinié, pmt, Ahc84: Thank you for proposing this property! I was just looking at the description of its values and quantities, and am wondering if it would be best to use angles rather than clock position in Wikidata. Technically, in descriptions of the die axis, 12:00 (and not 0:00) represents the starting point, 3:00 then represents 90 degrees, 6:00 represents 180 degrees. In terms of interoperable wikibase quantities, I think it would be best to edit this property so that it only takes the unit of degree, from 0 to 360. For example, if someone wanted to query for coins with a die axis < 60 degrees, it seems to me that a coin with a die axis of 12:00h or 0 degrees should also be returned--but it will only do so if the quantity is clearly sequential. Because wikibase quantities are not always easily comparable, I think it is also best to use the same unit wherever possible. Collections using clock hours can just multiply by 30. Valeriummaximum (talk) 20:17, 27 October 2020 (UTC)

@ Christelle Molinié: I edited the property at the very least so that minimum value is 12 o'clock and maximum value is 11 o'clock. It looks weird (because clock positions are not really a quantity) but 12 o'clock should not be the maximum value for die axis.Valeriummaximum (talk) 20:23, 30 October 2020 (UTC)

Hello @Valeriummaximum:I understand your point and I agree that it is not totally satisfying to have two ways to describe the same thing, but if we consider the American Numismatics Society database as a reference, using hours (direction) seems to be the standard. So if we decide to keep only one unit for a more efficient request, I would prefer hours, to stay as close as possible to academic uses. --Christelle Molinié (talk) 21:02, 7 December 2020 (UTC)

I completely understand your reasons here. My only concern is that the way the property was described, the minimum value was 0 and the maximum was 12 but this wasn't a correct representation of a clock. The issue then is that clock hours isn't really a true quantity type because the clock hand starts at 12 and ends at 11 while the angle measurement starts at 0 and ends at 359. Maybe I am being too picky. I uploaded as angles but I would be happy to change to whatever standard there is consensus on but the constraint values for minimum / maximum values does need fixing Valeriummaximum (talk) 00:29, 8 December 2020 (UTC)