[CF-metadata] Pre-proposal for "charset"

From: Jonathan Gregory <j.m.gregory>
Date: Thu, 23 Feb 2017 16:22:52 +0000

Dear Bob

> CF section 9.5 says: "The variable carrying the cf_role attribute may
> have any data type."
> And that makes sense, because some profile_id might be an integer and
> theoretically could be a single char.
>
>> Yes, I agree that on the basis of netCDF
>> alone
>> you can't tell whether it's a string or a 10-char array. However, the
>> cf_role
>> is a string-valued attribute, according to the CF convention, so it must
>> be a
>> string. I expect that for contents of netCDF files that follow the CF con-
>> vention this ambiguity shouldn't arise - but if there are cases where it
>> does
>> we should consider them.

Sorry. Being in a hurry, because you mentioned cf_role, I assumed you were
referring to the attribute, rather than the variable which has that attribute.

Looking again at the example you sent, I'd say that this file is not a proper
CF DSG file; it contains a number of variables which could be individual
timeseries, but they haven't been combined into a single data variable so
there is no element (or "station") dimension. The "timeseries" variable which
you asked about isn't referred to by any of the data variables. I agree that
its function is unclear, but I would say it's not CF-compliant anyway, so CF
doesn't need to provide an answer to this ambiguity. The file should look
like Example H3, H6 or H7 of the CF document.

Best wishes

Jonathan
Received on Thu Feb 23 2017 - 09:22:52 GMT