Spectral DM VOTable serializaiton issues

[Doug Tody]

Hi Alberto -

On Fri, 9 Mar 2007 amicol at sciops.esa.int wrote:
>
> That spread sheet is indeed very useful to data providers and SSAP
> developers.  Just one question about the many missing UCDs. Obviously,
> it would be very useful to complete such a list, but I guess that this
> requires the intervention of the Semantics WG.  I'm just curious to
> know what your comments are on this issue.

I would love to see the list of UCDs filled out as well.  We might be
able to make some headway on this ourselves, but if the Semantics WG
folks could help that would be even better.

We talked about doing just this back at the ADASS, but nothing ever came
of it.  Maybe those glaring empty spaces in my spreadsheet will motivate
someone to work on this.

BTW, I use this spreadsheet representation of the spectral data models
to autogenerate things like keyword dictionaries in my DALServer
code.  Others could do the same.  Any changes flow directly to the
implementation, and this approach ensures that when the same information
appears in multiple places it stays in sync.  Hence in a way, expressing
a data model in a form such as this can be definitive (and a lot simpler
than, e.g., UML based code generation) Note though, that elements of the
spreadsheet, such as suggested ID tags, are not part of the formal data
model and could be different in a different implementation.

	- Doug



> Quoting Doug Tody <dtody at nrao.edu>:
>
> > Hi Igor -
> >
> > This is not a direct response to your comments, but one thing I did
> > recently with SSAP (which I think has largely gone unnoticed) is enter
> > both the SSAP and Spectrum data models into a spreadsheet.  This makes
> > it much easier to get a uniform view of things like UTYPEs, UCDs, units,
> > what is provided and what is missing, etc., than trying to work all
> > this out from the documents.  You can find this at
> >
> >    https://webtest.aoc.nrao.edu/ivoa-dal/ssap-keywords.xls
> >
> > The spreadsheet should display in either Excel or OpenOffice.
> >
> > In doing this I found some cases where things like the UTYPEs were
> > inconsistent in the Spectrum document; these cases should be fixed in the
> > spreadsheet, but may not yet have been resolved in the specification.
> > Also, there are detailed examples of suggested UTYPE usage (both in
> > queries and in spectrum datasets) in the output that comes back from
> > the SSAP reference services.  Some of the details of how this is done
> > probably need further discussion.
> >
> > I still need to go back and note any differences from our current
> > specifications, but in considering further changes to Spectrum I suggest
> > we try to reference both the specification and the spreadsheet.
> >
> > 	- Doug
> >
>
>
>
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