The Unidata recommendations at (http://www.unidata.ucar.edu/software/netcdf/conventions.html) made sense to me:
If your conventions are hierarchical (general followed by more specialized) use the '/'. or If your conventions are not hierarchical, use the ',' (or space). But I suppose you are right that it doesn't really matter. Software that only works with UGRID-0.9 I'm sure will be happy if it finds UGRID-0.9 somewhere in the Conventions string. On Fri, Mar 13, 2015 at 2:28 PM, Nan Galbraith <[email protected]> wrote: > Hmmm, interesting point, Rich. The ACDD and OceanSITES conventions both > extend > CF, and both recommend a comma separated list in the Conventions attribute. > > There doesn't seem to be an explicit prohibition in the document against > using commas > for extensions of other conventions. It seems to me that the '/' in > conventions.html > refers to the old disk directory and URL scheme, where the documentation for > XXX > would be located at /pub/netcdf/Conventions/XXX and the Time_series > extension > would be at /pub/netcdf/Conventions/XXX/Time_series. > > Does the / convey any useful information? As long as both CF and UGRID are > listed, > isn't that enough? > > I can't see any reason why unidata chooses to promote 2 versions of this, > except maybe > for profiles, in which some of the requirements of a convention are dropped, > or assumed > to have default values, and not required by the profile. > > Cheers - Nan > > > > > On 3/13/15 1:59 PM, Signell, Richard wrote: >> >> David, >> >> I looked at this a bit and I'm not sure that >> http://cf-trac.llnl.gov/trac/ticket/76 actually captures this need, as >> UGRID is intended to *extend* CF, rather than a stand-alone >> alternative. >> >> For situations like CF and UGRID, which *extends* CF, it would appear >> from this guidance >> (http://www.unidata.ucar.edu/software/netcdf/conventions.html) >> that the foward slash separator should be used: >> >> Conventions = "CF-1.6/UGRID-0.9" >> >> This is discussed more in github issue >> >> (https://github.com/ugrid-conventions/ugrid-conventions/issues/11#issuecomment-79157891) >> >> -Rich >> >> P.S. Chris also points out that the current CF-1.6 document >> >> http://cfconventions.org/Data/cf-conventions/cf-conventions-1.6/build/cf-conventions.html >> there is an unfortunate error/typo that says the convention should look >> like >> >> Conventions = " CF-1.6 " (e.g. with spaces on either side of the quotes) >> >> Happily, this is gone in the 1.7 version at: >> >> http://cfconventions.org/Data/cf-conventions/cf-conventions-1.7/build/cf-conventions.html >> >> But perhaps it would be good to edit the CF-1.6 doc if that is indeed a >> typo. >> >> On Fri, Mar 6, 2015 at 7:21 AM, David Hassell <[email protected]> >> wrote: >>> >>> Hello Martin, >>> >>> Good news - this is covered by trac ticket #76 "More than one name in >>> Conventions attribute" (http://cf-trac.llnl.gov/trac/ticket/76). >>> >>> This has been accepted and should be in 1.7 (if it wasn't already in >>> 1.6?): >>> >>> It is possible for a netCDF file to adhere to more than one set of >>> conventions, even when there is no inheritance relationship among >>> the conventions. In this case, the value of the Conventions >>> attribute may be a single text string containing a list of the >>> convention names separated by blank space (recommended) or commas >>> (if a convention name contains blanks). This is the Unidata >>> recommended syntax from NetCDF Users Guide, Appendix B. If the >>> string contains any commas, it is assumed to be a comma-separated >>> list. >>> >>> For example: >>> >>> :Conventions = "CF-1.6 ACDD-1.0" ; >>> >>> >>> All the best, >>> >>> David >>> >>> ---- Original message from [email protected] (12PM 06 Mar 15) >>> >>>> Date: Fri, 6 Mar 2015 12:02:29 +0000 >>>> From: [email protected] >>>> To: [email protected] >>>> Subject: [CF-metadata] Applying multiple conventions >>>> >>>> Hello, >>>> >>>> There is a proposal floating around to use the UGRID conventions for >>>> unstructured grids in CMIP6 data. One issue is that the CF Convention >>>> specifies a specific string for the "Conventions" and the UGRID convention >>>> specific a different specific string. Is there any chance of modifying CF >>>> to >>>> accept, e.g. Conventions = "CF-1.8, UGRID-0.9"? >>>> >>>> regards, >>>> Martin >>>> >>>> > > > -- > ******************************************************* > * Nan Galbraith Information Systems Specialist * > * Upper Ocean Processes Group Mail Stop 29 * > * Woods Hole Oceanographic Institution * > * Woods Hole, MA 02543 (508) 289-2444 * > ******************************************************* > > > > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata -- Dr. Richard P. Signell (508) 457-2229 USGS, 384 Woods Hole Rd. Woods Hole, MA 02543-1598 _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
