From: Robert Muetzelfeldt <r.muetzelfeldt@ed.ac.uk>

Date: Mon, 10 Nov 2008 14:13:26 +0000

Message-ID: <49184186.7070803@ed.ac.uk>

To: www-math@w3.org

Date: Mon, 10 Nov 2008 14:13:26 +0000

Message-ID: <49184186.7070803@ed.ac.uk>

To: www-math@w3.org

Helo, I am in touch with a group (CF-metadata) [1] that is responsible for defining "standard names" [2] for variables in models and datasets within the climate change modelling community. The goal is to improve shareability of data between groups by associating standard metadata with the variables in each dataset. A standard name, such as "air_temperature_at_sea_level", is a text string generally composed from basic terms according to some rather informal guidelines. I am exploring the development of a markup language to capture the structure of such terms, in a way analogous to the relationship between plain-text mathematical expressions and MathML. As it happens, some of the terms that can be used to construct standard names are mathematical, e.g.: ratio_of_X_to_Y log10_of_X derivative_of_X_wrt_Y where X and Y are themselves standard names. So potentially a standard name could be ratio_of_pressure_to_log10_of_derivative_of_temperature_wrt_time which could be directly represented in Content MathML. The problem is that the variables are frequently complex terms: e.g. temperature_at_sea_level, or at least should be represented as such (to avoid a huge proliferation of terms in a controlled vocabulary, and to capture the inherent structure of the term). Therefore, rather than using a simple <ci> element for a term <ci>temperature_at_sea_level</ci> the ideal approach is something like: <ci> <standard_name xmlns="..."> <base_quantity>temperature</base_quantity> <location>sea_level</location> </standard_name> </ci> As I understand it, this is not legal in MathML. So the alternative seems to be to use the <semantics> element: <semantics> <ci>xxxx</ci> [Could be 'temperature_at_sea_level', but no real point, so use dummy content.] <annotation-xml encoding="Variable Markup Language"> <standard_name xmlns="..."> <base_quantity>temperature</base_quantity> <location>sea_level</location> </standard_name> </annotation-xml> </semantics> Not very pretty, but is this the best solution to the problem? Thanks! Robert Muetzelfeldt [1] http://cf-pcmdi.llnl.gov/ [2] http://cf-pcmdi.llnl.gov/documents/cf-standard-names -- The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.Received on Monday, 10 November 2008 14:14:22 GMT

*
This archive was generated by hypermail 2.2.0+W3C-0.50
: Saturday, 20 February 2010 06:13:02 GMT
*