[CF-metadata] physical vs dimensional units

From: Hattersley, Richard <richard.hattersley>
Date: Thu, 14 Apr 2011 16:43:15 -0000

Hi John,

> A "physical quantities" library separate from udunits could
> provide some assistance in detecting when two quantities can
> be added with unit convertsion, eg "add m and feet" but not
> "add mol/mol and m3/m3".
> > The udunits Unix command doesn't accept garbage garbage-1
> as a valid
> > unit, and nor should the Java version, I think.
>
> Thats good. I think the java library might be my fault,
> because I asked Steve to allow "unknown units" as a half step
> towards a "physical quantities" library. in retrospect, best
> to separate the two.

It's interesting you've toyed with "unknown units". Our group has been
through a similar process before deciding to make our unit handling more
strict. Arguably one should also get rid of "angle" as a unit (since
it's just: m/m = 1), but with the proviso that the "physical quantity"
information is still stored *somewhere*.

Which leads into ...

I'm curious how far you, or anyone else, has gone with the concept of a
"physical quantities" library. It seems strongly bound to the kind of
content provided by Roy Lowry's SKOS server.


Richard Hattersley AVD Expert Software Developer
Met Office FitzRoy Road Exeter Devon EX1 3PB United Kingdom
Tel: +44 (0)1392 885702 Fax: +44 (0)1392 885681
Email: richard.hattersley at metoffice.gov.uk Website:
www.metoffice.gov.uk
 
Received on Thu Apr 14 2011 - 10:43:15 BST