[kepler-dev] EML Unit information in Kepler

Dan Higgins higgins at nceas.ucsb.edu
Thu Sep 28 09:46:10 PDT 2006


Edward,

    Thanks for the reminder about the Ptolemy unit systems. The specific 
problem we were having is getting the unit from a Kepler-specific EML 
data source. If we can figure out how to automatically get the unit from 
this source, then using one the Ptolemy unit systems would appear to be 
a good option!

Dan

Edward A. Lee wrote:
>
> Dan,
>
> There are two unit systems in Ptolemy II, one that is dynamically
> checked and one that is statically checked. Conversions are automatic.
> Are you using one of these?
>
> Edward
>
> At 09:48 AM 9/27/2006, Dan Higgins wrote:
>> 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
>>
>> -- 
>> *******************************************************************
>> 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
>> *******************************************************************
>>
>>
>> _______________________________________________
>> Kepler-dev mailing list
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>
> ------------
> Edward A. Lee
> Professor, Chair of EECS
> 231 Cory Hall, UC Berkeley, Berkeley, CA 94720-1770
> phone: 510-642-0253 or 510-642-0455, fax: 510-642-2845
> eal at eecs.Berkeley.EDU, http://ptolemy.eecs.berkeley.edu/~eal 
>


-- 
*******************************************************************
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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