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Request for: each #275

Open anisa123457 opened 11 months ago

anisa123457 commented 11 months ago

Please provide the following a literature reference (or attachment) which provides a scientific definition. A scientific definition is a quantitative one, not just words "unit for the amount of XYZ." A scientific definition will also give some way of converting or inferencing something with the values expressed using that unit. You can include document URLs or drag/drop attachments to accompany your request.

Note the scope of UCUM is science, healthcare, engineering, and business (not including currencies). Units outside this context are discouraged.

Be certain to include the unit in the issue title above.

incansvl commented 9 months ago

At first glance the idea of an "each" unit seems to be just another example of a countable entity. Indeed it could be one synonym of the general concept of a coutable entity, alongside other potential names like thing item entity etc. However it seems less natural to use in practice that any of those other synonyms (none of which exist at the moment BTW).

For example, imagine having a UCUM unit called beast with the value 1 (unity). This would be convenient for farmers who could write expressions like-

Mean carcass weight of prime beef cattle: 346.1 kg/beast Animals in shipment: 12 beast

The lack of the plural "s" in the X beast expression is a little awkward but it sort-of works.

By comparison, if we rewrite those in terms of each:

Mean carcass weight of prime beef cattle: 346.1 kg/each Animals in shipment: 12 each

IMHO the division by an each makes some sense, intuitively. However multiplying by an each, while a no-op in semantic terms, is actively confusing when it comes to understanding what the expression is aiming to convey.

In general terms, as noted at the outset this seems to be yet another example of the (infinitely large) set of "named countable things" discussed in other issues including #224

incansvl commented 9 months ago

Note for Owner/Moderator

BTW in case the repo owner is wondering "who the heck is this incansvl character?", earlier comments in the repo were made under my UK NHS github id colin-e-hscic however as I have now retired from the NHS I no longer have access to that id, so I must use a personal login id. I hope that doesn't cause any upset.