jmandel
commented
9 years ago If you haven't seen the UCUM specification (of which this library is an implementation) you probably want to check out: http://unitsofmeasure.org/ucum.html
(I didn't design this library to handle units "in general" -- just as an implementation of the UCUM spec. So the kinds of design questions you've raised didn't really come up for me.)
Re: JS numerics, it would probably make sense to use an arbitrary precision numerics library (e.g. https://github.com/MikeMcl/big.js/) rather than JS's built-in numeric types. I just haven't gotten around to incorporating this into ucum.js.
govpack
Noticed you are doing a rusty version too, do you have the spec as a csv? i saw the xml spec, maybe i should parse that into json? or is there something else?
What do you think about the departures from SI units: grams instead of kg seems fine, Kelvin instead of Celsius (as SI has it) seems a choice only for scientists, and dropping the mol? The good thing about doing an implementation is that you can add extensions that work exactly as you like.
And that the whole idea is to use any/all units, and whichever ones you want, so to have a set of preferred ones: systemX, systemY, BobsPreferredUnits, etc which could be configured as to how the units show up in different places.
Units:
and to instantly remix and re-display values+units based on configurable preferences, in a dynamic MVC sort of a situation.
Conversions of "like to like" would be the first thing [as ucum.js does at the moment]
Is anything being done with the algebraics of -- or equations with units in JS? (I will avoid that at the moment, but once you have the units, one will want to have the mathematical operators as well)
How about mapping to the SI symbols in unicode, or outputs that support such?
㍱ ㍲ ㍳ ㍴ ㍵ ㍶ ㍷ ㍸ ㍹ ㍺ ㍻ ㍼ ㍽ ㍾ ㍿ ㎀ ㎁ ㎂ ㎃ ㎄ ㎅ ㎆ ㎇ ㎈ ㎉ ㎊ ㎋ ㎌ ㎍ ㎎ ㎏ ㎐ ㎑ ㎒ ㎓ ㎔ ㎕ ㎖ ㎗ ㎘ ㎙ ㎚ ㎛ ㎜ ㎝ ㎞ ㎟ ㎠ ㎡ ㎢ ㎣ ㎤ ㎥ ㎦ ㎧ ㎨ ㎩ ㎪ ㎫ ㎬ ㎭ ㎮ ㎯ ㎰ ㎱ ㎲ ㎳ ㎴ ㎵ ㎶ ㎷ ㎸ ㎹ ㎺ ㎻ ㎼ ㎽ ㎾ ㎿ ㏀ ㏁ ㏂ ㏃ ㏄ ㏅ ㏆ ㏇ ㏈ ㏉ ㏊ ㏋ ㏌ ㏍ ㏎ ㏏ ㏐ ㏑ ㏒ ㏓ ㏔ ㏕ ㏖ ㏗ ㏘ ㏙ ㏚ ㏛ ㏜ ㏝ ㏞ ㏟
I mainly just want to just pull out the table of conversion factors, the short ascii notation for each, as an enumerated list for each base unit (starting from 1, being the system default), and then generate or have functions to parse, convert or serialize, and add in any extras for js-dates, prices, pixels and on screen dimensions currency (with some way to go slide thru time or go historical, because those conversion factors change, as do some of the universal constants, but i'll leave that sort of precision to the actual scientists). I want to do the currency values high (like 1e6==$1, or 1e6=1g of silver for the commodities) and keep them as integers, to avoid rounding errors, ie to move any possible significant figures to the left of the decimal point, mainly because JS lacks a good decimal type, and that's where we're at, at the moment. .