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#79: Handling and formatting of vector quantities in CF -----------------------------+---------------------------------------------- Reporter: lavergne | Owner: [email protected] Type: enhancement | Status: reopened Priority: medium | Milestone: Component: cf-conventions | Version: Resolution: | Keywords: vector -----------------------------+---------------------------------------------- Comment (by lavergne): Replying to [comment:61 ngalbraith]: > Could it be simplified to: > > {{{ > > int drift_vector; > drift_vector:cf_role='vector'; > drift_vector:group_name='sea_ice_drift_vector'; > drift_vector:long_name = "sea ice drift vector" ; > drift_vector: components = "dX, dY, dir" ; > }}} > > The variables dX, dY, and dir would then be responsible for identifying themselves fully as to their role in the vector. I've read through the comments above and I see the i_ and j_component being proposed, but not adopted, and I don't find the rationale behind this. Thank you, we are back where we started, 60 comments ago :) This is exactly what I was advocating for in the text opening this ticket, and later in the implementation I proposed on August 21st (post #33). The reasons why many then advocated for introducing a more detailled listing of the components (like i_component, magnitude, etc...) are mainly: 1) it proves cumbersome to rely on parsing standard names for deciding if a component is a magnitude, a direction, or a x component; 2) standard_names are not mandatory and sometimes "under approval", and vectors could need a way to be defined with "non standard" components; I did not fully buy the first argument, but I must say the second convinced me. I am still puzzled on how we are going to check the validity of a vector variable that defines "sea_ice_x_displacement" as "ij_direction". How will a CF checker handle that? The only way I see is to introduce the link between component attributes and standar names in the standard name table: "sea_ice_x_displacement" can only appear as either a "i_component" or a "j_component", or a "k_component". And if we do that, argument 1) in my list above partly falls. Thomas -- Ticket URL: <https://cf-pcmdi.llnl.gov/trac/ticket/79#comment:62> 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.
