[CF-metadata] Coordinate System nomenclature in netcdf-java-2.2 / CDM:

[John Caron]

Brian Eaton wrote:

>Hi John (and Russ),
>
>To me "axis" has strong connotations of 1D and straight lines.  I searched
>through the online Oxford English Dictionary entry for "axis" and found the
>string "straight line" matched 8 times.  Using "coordinate variable" for
>the 1D object, and "coordinate axis" for the multi-dimensional objects is
>backwards from the meanings I would expect.
>
>Earlier in the draft stages of CF I tried using "coordinate axis" for 1D
>coordinate variables, and "coordinate variable" as the generalization.  But
>it was awkward to be constantly explaining "it's a coordinate varible, but
>not a netCDF coordinate variable".  In the end consistency with the NetCDF
>User's Guide usage won the day.
>
>If there's any chance that the NetCDF-4 User's Guide usage could change,
>please consider starting from scratch with the meaning of "coordinate
>variable".
>
>Thanks,
>Brian
>
>  
>
yeah, i agree, but we decided we couldnt hijack "coordinate variable" 
and make it mean something new.

i think "coordinate axis" is not as counter-intuitive as you might, uh, 
intuit ;^)

even though it may have a multidimensional domain, its range is always 
scalar, ie its a function f : D -> R, where R = real numbers. Its the 
range thats constitutes the axis, eg "latitude" or  "height above msl".