Vocabularising dataproduct_type

[Laurent Michel]

Markus

Le 10/03/2020 à 15:01, Markus Demleitner a écrit :
> Hi Laurent,
> 
> On Tue, Mar 10, 2020 at 02:07:48PM +0100, Laurent Michel wrote:
>>> So... what do you suggest to fix this?  The definition I'm currently
>>> proposing is
>>
>> I propose :
>> measurements: A set of derived measurements obtained from a particular
>> original dataset or a catalog of sources compiled from various progenitors.
> 
> I've put that in in rev. 5741 (but I've not uploaded it to
> ivoa.net/rdf yet), but very frankly I'm not thrilled by "a
> catalog of sources compiled from various progenitors" because that's
> a *very* wide definition.  In particular, I'm always getting a bit
> queasy when things get as close to tautologies as "derived from <one
> or more> progenitors" -- I'd argue that isn't a restriction on
> "catalog" at all.
> 
> If you follow that objection, then what's left of the definition is
> 
>    A set of derived measurements obtained from a particular original
>    dataset or a catalog of sources.

This is fine to, as long you do not assume that catalog is something "extracted from one image".
Catalog products are part of the things that are not clearly defined but that all of us use everyday though.
> 
> Hm.  I suspect that's not quite what people wanted, was it?
> 
> Perhaps it's time to take a step back and ask ourselves what the
> concept actually is, i.e., what is the set of things this term should
> address, perhaps as a list of files that is a "measuremen" and,
> equally importantly, a list of files that is not?
> 
> Since I'd still like to make this reflect obscore usage: was there a
> collection of use cases back when this term was added to the list of
> allowed dataproduct_type values?
> 
> And talking about obscore usage, I've just run a global obscore query
> for
> 
>    SELECT TOP 1000
>    access_url
>    FROM ivoa.obscore
>    WHERE dataproduct_type='measurement'
> 
> [2] and got back zero rows[1].
> 
> This would perhaps indicate that the term isn't all that required and
> could be left out for now?

I would really prefer the list of dataproduct_type to ensur an ascending compatibility with Obscore. I believe it is worth to 
keep as fas as possible a consistance betwenn standards. This might help in many cases to map things from one context to another.
If someone need to implement something matching "Measurement" and if that word is not in the vocabulary but is in Obscore; then 
he/she will turn toward something inapropriate but available.

Laurent

> 
>             -- Markus
> 
> 
> [1] Disclaimer: I ^C-ed out of CSIRO ASKAP and IAPS TAP because I
> lost patience with them; so, if they have measurement-typed rows, I'd
> have missed them.
> 
> [2] In case you'd like to experiment with global obscore queries,
> here's the pyvo program I've used:
> 
> import pyvo
> 
> QUERY = """
> SELECT TOP 1000
>    access_url
> FROM ivoa.obscore
> WHERE dataproduct_type='measurement'
> """
> 
> 
> def query_obscore():
>      results = []
>      for svc_rec in pyvo.registry.search(datamodel="obscore"):
>          print("Querying {}".format(svc_rec.res_title))
>          try:
>              svc = pyvo.dal.TAPService(svc_rec.access_url)
>              results.append(
>                  svc.run_sync(QUERY))
>          except KeyboardInterrupt:
>              # someone lost their patience with a service.  Query next.
>              pass
>          except Exception as msg:
>              # some service is broken; you *should* complain, but
>              # then let's be lazy here
>              print("  Broken: {} ({})\n".format(
>                  svc_rec.access_url, msg))
>          
>      return table.vstack(results)
> 
> 
> def main():
>      tab = query_obscore()
>      print(tab)
>      
> 	
> if __name__=="__main__":
>      main()
> 

-- 
jesuischarlie/Tunis/Paris/Bruxelles/Berlin

Laurent Michel
SSC XMM-Newton
Tél : +33 (0)3 68 85 24 37
Fax : +33 (0)3 )3 68 85 24 32
Université de Strasbourg <http://www.unistra.fr>
Observatoire Astronomique
11 Rue de l'Université
F - 67200 Strasbourg