[kepler-dev] EML Unit information in Kepler

[Dan Higgins]

Hi Matt,

    During my recent discussions with Akiko Ogawa, a limitation in the 
current EML2 dataSource actor came up. The basic problem is that with 
the current implementation, there is no way to programatically  get the 
units of attributes! The ports are automatically created and type 
information (e.g. ints, doubles, etc) assigned, but Akiko wanted to have 
the units of each attribute available so that unit conversion could 
automatically take place. [The hope was to have actual unit info and 
desired unit info available as inputs to an actor that could convert the 
actual units to the desired unit for output to some model. This would 
involve reading the actual unit from EML and having the actor figure out 
how to convert it to the desired unit and then apply that conversion to 
all of the data referred to be the EML attribute.]

    Clearly this unit question is similar to that for any type of 
metadata. How do we do automatic conversion? Units are iust a obvious 
case. Unfortunately, our EML2 DataSource actor does not provide any of 
the unit information.

    I am not at all sure how we should/could provide this unit 
information. Will it come with the semantic annotations tied to 
measurement ontologies, or is it a special case that we could handle 
some other way (especially for EML2 actors where the information is 
already in the EML metadata). I think it is a feature that Akiko would 
like to see in Kepler as soon as possible, so I a am suggesting that we 
give it some consideration in the near future.

Dan

-- 
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Dan Higgins                                  higgins at nceas.ucsb.edu
http://www.nceas.ucsb.edu/    Ph: 805-893-5127
National Center for Ecological Analysis and Synthesis (NCEAS) Marine Science Building - Room 3405
Santa Barbara, CA 93195
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