[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

gerritbot added a comment. Change 319401 abandoned by Smalyshev: Tools for creating unit conversion config Reason: we can do it without backporting https://gerrit.wikimedia.org/r/319401TASK DETAILhttps://phabricator.wikimedia.org/T117032EMAIL

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

gerritbot added a comment. Change 298407 merged by jenkins-bot: Tools for creating unit conversion config https://gerrit.wikimedia.org/r/298407TASK DETAILhttps://phabricator.wikimedia.org/T117032EMAIL PREFERENCEShttps://phabricator.wikimedia.org/settings/panel/emailpreferences/To: Smalyshev,

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

Stashbot added a comment. Mentioned in SAL (#wikimedia-operations) [2016-10-06T21:53:06Z] Synchronized wmf-config/Wikibase-production.php: SWAT: [[gerrit:311206|Add config for units on Wikidata (T117032)]] PART II (duration: 00m 50s)TASK

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

Stashbot added a comment. Mentioned in SAL (#wikimedia-operations) [2016-10-06T21:51:28Z] Synchronized wmf-config/unitConversionConfig.json: SWAT: [[gerrit:311206|Add config for units on Wikidata (T117032)]] PART I (duration: 00m 48s)TASK

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

Smalyshev added a comment. If there's no conversion to SI units or no SI units, we shouldn't use P2370. We should use P2442 instead. SI is well-defined system and we should only use SI properties to signify SI units. But we do plan to support other units, just a bit later after we see how the

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

daniel added a comment. @Smalyshev @Esc3300: When extracting conversion factors from statements on Wikidata, we should only use factory that are marked +/- 0. +/-0 indicates that the factory applies per definition, which is what we want for conversion. For things like calendar year, month, or

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

Esc3300 added a comment. Initially https://www.wikidata.org/wiki/Property:P2370 (conversion to SI units) wasn't used for units that don't have a reliable conversion to these (e.g. calendar year, month, historic units). What is the plan for these? Should we leave P2370 or use something else? TASK

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

gerritbot added a comment. Change 311206 had a related patch set uploaded (by Smalyshev): Add config for units on Wikidata https://gerrit.wikimedia.org/r/311206TASK DETAILhttps://phabricator.wikimedia.org/T117032EMAIL

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

Smalyshev added a comment. More mismatches: DIFF: [congius(Q3646719)->cubic metre]: GNU 0.0034806123936, ours 0.00323 DIFF: [sextarius(Q14333713)->cubic metre]: GNU 0.0005801020656, ours 0.000546 DIFF: [choinix(Q15794456)->cubic metre]: GNU 0.00108, ours 0.001087 DIFF: [amphora(Q2844434)->cubic

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

Smalyshev added a comment. So I checked our data against GNU units data and found these mismatches, among used units: DIFF: [stadion(Q1645966)->metre]: GNU 189.738, ours 186 DIFF: [plethron(Q2099374)->metre]: GNU 31.623, ours 29.55 DIFF: [scruple(Q1573593)->kilogram]: GNU 0.0012959782, ours

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

Smalyshev added a comment. We need then a solution to introduce new unit conversions into dataset. Currently the only way it full reload, but in theory we can add new conversions incrementally. Not change though, change is more complex.TASK DETAILhttps://phabricator.wikimedia.org/T117032EMAIL

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

Lydia_Pintscher added a comment. I'd prefer starting small and then extending on-demand.TASK DETAILhttps://phabricator.wikimedia.org/T117032EMAIL PREFERENCEShttps://phabricator.wikimedia.org/settings/panel/emailpreferences/To: Lydia_PintscherCc: Lydia_Pintscher, TomT0m, gerritbot, Smalyshev,

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

daniel added a comment. To use GNU units, we'll at least need a mapping between item IDs and GNU unit symbols. Anyway @Smalyshev do you think it makes sense to start small, with a manually written config of maybe 100 units, or do you think we should try to cover as much as possible right

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

Smalyshev added a comment. BTW, if we really wanted to use GNU units, I think it won't be hard to create UnitStorage driver that uses it, or generate JSON config from it, but I am not sure it's better than having one generated from Wikidata.TASK DETAILhttps://phabricator.wikimedia.org/T117032EMAIL

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

Smalyshev added a comment. True, these are the issues. This is why I propose the two-stage scheme, where units config file is generated from Wikidata statements, but this should be done very rarely once initial version is created. Mostly updates will be only new unit additions, and changing

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

daniel added a comment. In T117032#2609531, @TomT0m wrote: Maybe instead of this configuration we can make the mechanism more flexible by just specifying such a property on the database. The set of unit supported by the export could then be extended with no privilege at all. The problem is that

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

Smalyshev added a comment. @TomT0m yes, we plan to use "conversion to SI unit".TASK DETAILhttps://phabricator.wikimedia.org/T117032EMAIL PREFERENCEShttps://phabricator.wikimedia.org/settings/panel/emailpreferences/To: SmalyshevCc: TomT0m, gerritbot, Smalyshev, Aklapper, daniel, aude, mschwarzer,

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

TomT0m added a comment. Hi, maybe I come after the battle, but if you're not aware of this, Wikidata has now a "conversion to SI unit" that could come valuable for this as it stores the value of the configuration file. Maybe instead of this configuration we can make the mechanism more flexible by

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

gerritbot added a comment. Change 298407 had a related patch set uploaded (by Smalyshev): Tools for creating unit conversion config https://gerrit.wikimedia.org/r/298407TASK DETAILhttps://phabricator.wikimedia.org/T117032EMAIL

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

Smalyshev added a comment. One more concern - to actually do the calculations, we may need arbitrary precision arithmetics... And we need a fast one if we want to do it inside dump. We can maybe require bcmath/gmp to calculate normalized values. But some of those will be big, like:

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

Smalyshev added a comment. Makes sense, thanks @daniel. TASK DETAIL https://phabricator.wikimedia.org/T117032 EMAIL PREFERENCES https://phabricator.wikimedia.org/settings/panel/emailpreferences/ To: Smalyshev Cc: Smalyshev, Aklapper, daniel, aude, debt, jkroll, Wikidata-bugs, Jdouglas,

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

Smalyshev added a comment. Note that we have https://www.wikidata.org/wiki/Property:P2370 now, so I wonder how the two should be interplaying. TASK DETAIL https://phabricator.wikimedia.org/T117032 EMAIL PREFERENCES https://phabricator.wikimedia.org/settings/panel/emailpreferences/ To:

[Wikidata-bugs] [Maniphest] [Commented On] T117032: Create configuration for specifying units conversions

daniel added a comment. In addition to the multiplier, we need at least an optional offset (for °F to °C conversion) and perhaps also an exponent (for reciprocal conversions like miles/gallon to liter/100km). Both can come from GNU Units. TASK DETAIL