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[Support #DOV-245654]: case of unit names

Hi Jonathan,

> I was surprised to find that the cf-checker accepted DAYS as a valid unit, but
> I understand from Ros and the udunits guide that in udunits-2 the names of
> units (not the symbols) are case-insensitive. I am pretty sure that it is
> quite often stated that units names (at least SI) are lower case. For 
> instance,
> it is "joule", not "Joule", despite its being named after a person. The
> detailed NIST guide, which udunits follows, also appears to uphold this in
> sect 9.1 of http://physics.nist.gov/Pubs/SP811/sec09.html
> "When spelled out in full, unit names are treated like ordinary English 
> nouns. Thus the names of all units start with a lower-case letter, except at 
> the beginning of a sentence or in capitalized material such as a title."
> Could udunits-2 be made to follow this rule?

Good question!

The UDUNITS-2 package could be made to follow this rule but I'd recommend 
against it. There's a general principle in programming that says "Be generous 
in what you take-in but very particular in what you give-out. In this situation 
it means that the UDUNITS package should be generous in what it accepts for 
unit strings and finicky in what it prints for a unit. I know for a fact that 
there are scientific and engineering systems out there that spell their unit 
names in all capital letters; ergo, the UDUNITS package accepts that. As you 
know, this is not the case for unit symbols because there, unlike unit names, 
capitalization can change the meaning of a symbol.

> Best wishes
> Jonathan

Steve Emmerson

Ticket Details
Ticket ID: DOV-245654
Department: Support UDUNITS
Priority: Normal
Status: Closed