[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Re: ANN: a portable data component -- length
> On 10/04/2011 06:23, Toby Considine wrote: >> Interesting question, and one that goes to the heart of some of my >> current >> obsessions... >> >> Is there a standard XSD of SI units for inclusion somewhere on the >> web >> Is there a standard XSD of SI scale ( peta / tera / giga / mega/ >> ...) for >> inclusion anywhere on the web? You are probably aware of the W3C note "Units in MathML" http://www.w3.org/TR/mathml-units/ This takes the route of assigning URLs to all the concepts. The publishing industry (and perhaps other printing/manufacturing industries) have two particular requirements that may not be obvious. These are: 1) Most people use metric, some quaint countries use imperial, and some other countries may have their own native measures (such as the Japanese Q?). So rather than issues of absolute precision in measurements, it is needed to have some system of units in which allows exact inter-conversions: i.e. converting between inches and cm repeatedly will cause any accumulated round-off errors. (TeX, Adobe and Microsoft all have their own versions of these. These are standardized in ISO PDF and ISO OOXML, and I think ISO ODF uses Adobe's system.) 2) Some interfaces allow users to enter numbers like 1/3". So the metrical base described above has to cope with exact representations of these as well. i.e. what base is required so that integer multiples yield 1", 1cm, 1/8"i, 1/8cm, i/3", 1/3cm precisely? If you are wanting an exhaustive list of metrical units, include 2 different kinds of cubits, ISO10744 HyTime had such a thing. This standard is no longer current, but still may be a good reference. Cheers Rick Jelliffe
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] |
PURCHASE STYLUS STUDIO ONLINE TODAY!Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced! Download The World's Best XML IDE!Accelerate XML development with our award-winning XML IDE - Download a free trial today! Subscribe in XML format
|