Dear Charlie I think it's fine to permit the new types, and thanks for the proposed text. I would not be in favour of removing the valid_* attributes, because this is not their sole use. It would be a backwards-incompatible change - I don't think we have so far done that - and doesn't seem necessary to me. But perhaps you mean to keep the attributes but deprecate their use to indicate whether a data type is unsigned? That would be fine.
Best wishes Jonathan ----- Forwarded message from Charlie Zender <[email protected]> ----- > Date: Tue, 26 Sep 2017 13:39:38 -0700 > From: Charlie Zender <[email protected]> > To: CF Metadata Mail List <[email protected]> > Subject: Re: [CF-metadata] Add new integer types to CF? > User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:52.0) > Gecko/20100101 Thunderbird/52.3.0 > > If there is strong opposition to replacing the valid_* method in > CF <= 1.7 with the _Unsigned method in CF 1.8 then please speak-up. > People seem to prefer _Unsigned (as described in NUG) to the > previous CF standard method (valid_*) as way to allow CDF1, CDF2, > and netCDF4-classic to indicate unsigned integers in CF 1.8. > New datasets could still use the valid_* method but that would > restrict their CF-compliance to <= 1.7. CDF1 and CDF2 and > netCDF4-classic datasets intended for CF 1.8 compliance would have > to use _Unsigned instead of valid_*. > > This plan could be enacted with wording like this: > > "The netCDF data types char, byte, unsigned byte, short, unsigned > short, int, unsigned int, int64, unsigned int64, float or real, > and double are all acceptable. The char type is not intended for > numeric data. One byte numeric data should be stored using the byte > or unsigned byte data type. Unsigned types should be used for unsigned > data if possible. If the underlying file format does not support > unsigned types, integer or byte variables that are to be interpreted > as unsigned must have the attribute _Unsigned = "true". The convention > explicitly distinguishes between signed and unsigned integer types > only where necessary. Unless otherwise noted, int is interchangeable > with unsigned int, int64, and unsigned int64 in this convention, > including examples and appendices. Similarly short is interchangable > with unsigned short, and byte with unsigned byte." > > Comments welcome... > -- > Charlie Zender, Earth System Sci. & Computer Sci. > University of California, Irvine 949-891-2429 )'( > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata ----- End forwarded message ----- _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
