This message came from the CF Trac system. Do not reply. Instead, enter your comments in the CF Trac system at https://cf-pcmdi.llnl.gov/trac/.
#74: Allow sharing of ancillary variables among multiple data variables ---------------------------------------+------------------------------------ Reporter: [email protected] | Owner: [email protected] Type: enhancement | Status: new Priority: medium | Milestone: Component: cf-conventions | Version: Resolution: | Keywords: "ancillary data" "standard name modifiers" ---------------------------------------+------------------------------------ Comment (by ngalbraith): Replying to [comment:24 [email protected]]: > "In the case where more than one data variable, each with a standard name, references an ancillary data variable (see Section 3.4, “Ancillary Data”) for the same reason (e.g. status_flag), the standard_name attribute for the ancillary data variable is composed of a blank-separated list of each unique standard name followed by one or more blanks and a standard name modifier." I really seem to be out of step, but honestly I still don't see what we're gaining here. More important, I think we're making assumptions about the role of a standard name in an ancillary variable that may lead to problems sharing data. IMHO, in a file with multiple variables that share one or more ancillary variables, there is no need - and no really reliable method - for the ancillary variables to list '''all''' their parents. This is a one-way connection; a primary variable points to its ancillary variables, using short names. Is there a use case for ancillary variables to identify their primary variables? If we actually need a 2-way system, is there a sense that this method - listing all the primaries' standard names - will work? What happens when there are multiple 'primary' variables with the same standard name in a file? What's wrong with this: {{{ float swt(time,depth,lat,lon); swt:standard_name="sea_water_temperature"; swt:ancillary_variables="swt_nobs"; float swpt(time,depth,lat,lon); swpt:standard_name="sea_water_potential_temperature"; swpt:ancillary_variables="swt_nobs"; int swt_nobs(time,depth); swt_nobs:standard_name="sea_water_temperature number_of_observations"; }}} -- Ticket URL: <https://cf-pcmdi.llnl.gov/trac/ticket/74#comment:25> CF Metadata <http://cf-pcmdi.llnl.gov/> CF Metadata This message came from the CF Trac system. To unsubscribe, without unsubscribing to the regular cf-metadata list, send a message to "[email protected]" with "unsubscribe cf-metadata" in the body of your message.
