Hi David, that is true. My question was whether there should be, as Jonathan proposes, a restriction on the dimensions that "where type1" can be associated with,
cheers, Martin ________________________________ From: David Hassell [david.hass...@ncas.ac.uk] Sent: 20 May 2016 13:03 To: Juckes, Martin (STFC,RAL,RALSP) Cc: cf-metadata@cgd.ucar.edu Subject: Re: [CF-metadata] weighted time mean vs. conditional time mean. Hi Martin, I think that the compliance document and 7.3.3 consistently force the "type1" in "where type1" must come from the area_types controlled vocabulary (http://cfconventions.org/Data/area-type-table/current/build/area-type-table.html), or be the name of a coordinate with area_types as it values: "The valid values for type1 are the name of a string-valued auxiliary or scalar coordinate variable with a standard_name of area_type, or any string value allowed for a variable of standard_name of area_type" I've just noticed that the area-types table linked above, updated 3 days ago, includes some of the things you're interested in: "cloud", "clear_sky", "dust_aerosol" - I don't know when these got added, or how they are defined, but if they're alright, then I see no reason why "where can not be used. All the best, David On 20 May 2016 at 12:09, <martin.juc...@stfc.ac.uk<mailto:martin.juc...@stfc.ac.uk>> wrote: Hello Jonathan, Jim, Just picking up the thread again. There is an issue, it appears, about the use of the "where" modifier for cell_methods elements other than "area:". Jonathan believes "where" should only apply for area on the basis that this where the motivation comes from in the first paragraph of section 7.3.3. The subsequent paragraphs in section 7.3.3. describe the use of "where" with a generic element "name: ....". The compliance document clearly states that "where" can be used with any string. The specific use case is to specify how the mean should be taken when there is a temporarily varying area_type. Jonathan has suggesed using a suitably formulated free-text comment in brackets ("time: mean (when cloud present)") but I would prefer a formulation with an explicit conventional meaning: "time: mean where cloud". So there are two questions: (1) Can "where" be used, as stated by the convention, with any coordinate? (2) If there is a clear consensus that "where ...." can only be used for "area", then can we update the convention, conformance requirements and CF checker to be consistent with this? regards, Martin _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu<mailto:CF-metadata@cgd.ucar.edu> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata -- David Hassell National Centre for Atmospheric Science Department of Meteorology, University of Reading, Earley Gate, PO Box 243, Reading RG6 6BB Tel: +44 118 378 5613 http://www.met.reading.ac.uk/ _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
