Dear Thomas, and colleagues, Thank you for bringing this topic back in the spot lights. I made an attempt to define vectors in CF about 4 years ago. There was a lot of good discussion in here (http://cf-trac.llnl.gov/trac/ticket/79) but we unfortunately never reached a conclusion (although there was some level of consensus at the start). I will gladely participate to this discussion.
T. 2016-10-27 21:23 GMT+02:00 Clune, Thomas L. (GSFC-6101) < [email protected]>: > I could not find any discussion in the specs about how to indicate that > two variables are part of a vector pair such as (u,v). In theory one can > infer the relationship from the long-name, but it would seem to be useful > to have a more direct means to indicate this relationship. > > I see at least 4 different approaches to this: > > > 1. Each variable that is part of a vector has an attribute that names > the partner component. u:vector_partner = “v" There is also an attribute > that specifies the component index: u:vector_index=1 Others may want > vectors with more components, in which case naming the partners becomes > more problematic. And then one would also want an attribute that > specifies the total number of components u:vector_length=2 > 2. Each vector component has an attribute that names the entire vector > rather than the partner. u:vector_name=“u-v”. There would also be an > attribute for specifying the vector component index as in (1) above. This > approach is more scalable for longer vectors, but tools would need to > search through all variables to find the partner components. > 3. Have a separate variable which is a vector of strings. Each string > names the list of component variables with some standard separator. E.g., > “u,v”, “mx, my”, … > 4. Combine components into one variable with an extra vector index > dimension. But this seems to be contrary to CF conventions for naming > variables. It is also not very friendly to the tools that we are > currently using. > > > Thanks in advance, > > - Tom > > > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > > -- ========================================== Thomas Lavergne Norwegian Meteorological Institute P.O.BOX 43, Blindern, NO-0313 OSLO, Norway Phone: (+47) 22963364 <callto:+47%29%2022963364> Skype: thomas.lavergne <callto:+47%29%2022963380> Email: [email protected] OSISAF HL Portal: http://osisaf.met.no ==========================================
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