Phucnt.nii

Si conversion

Hi Phucnt.nii,

For conversion to metric units, please help us by ensure that all convertable units have conversion to SI unit (P2370) pointing to their base unit. This allows to do conversions between them and makes conversion to standard unit (P2442) statements among them unneeded. Some units can't be converted to SI units and for these P2442 can be helpful.
--- Jura 15:22, 11 September 2017 (UTC)

Re: SI Conversion

Hi Jura1, Thank you for your suggestion. I will try to add the P2370 SI conversion in each unit of measurement.

So, I have one question related to the unit conversion. For formula cases such as Q25267 (degree Celcius), the P2370 is not a factor, see the defining formula. How can we define a formula for such cases? It seems that Sandbox-String can help in conversion. Why do we put this formula to P2370?

Best, Phucnt.nii (talk) 23:57, 11 September 2017 (UTC)

It's still an open question: the Sandbox-strings for Kelvin was just a sample for Phabricator:T174353. If it's actually being used, maybe we would need to create a separate property or use "defining formula".

At some point, P2370 values were retrieved and used as a configuration for normalized quantity values available on https://query.wikidata.org . The "Units" queries on property talk pages for properties with quantity datatype list them as well, e.g. on Property talk:P2102 (upper right corner).
--- Jura 09:43, 12 September 2017 (UTC)

I have started a discussion that is relevant to your edit to year (Q577) Jc3s5h (talk) 18:28, 19 September 2017 (UTC)

edits on unit items

@Phucnt.nii: I've reverted your removal of "SI derived unit" on a number of unit items, as it is helpful to know whether a unit is based on SI or something else, I don't see the benefit in your removing these P31 statements. You also removed some "unit used for this property" statements but I think you need to be careful - those were added for a reason and have UI and constraint impacts. On what basis do you think that metre (Q11573) cannot be used for personal best (P2415) (what about high jump heights or ski jump distances, for example)? In addition, some of your other edits look a bit dubious - while "pascal second" is a unit in which you can measure dynamic viscosity, I don't think it is legitimate to call it an instance of "dynamic viscosity" in itself. You could call it an instance of "unit of dynamic viscosity" but I don't think we have such an item right now. I suggest you look at how other things have been modeled in wikidata before making extensive edits like this. "What links here" is a good tool to browse around and see how things have been done. ArthurPSmith (talk) 14:59, 15 December 2017 (UTC)