VOEvent References

[Rob Seaman]

Matthew, Mike,

What do you guys think?

Rob
--
On Mar 16, 2011, at 10:31 AM, Roy Williams wrote:

> Rick
> 
> On 03/16/2011 2:23 AM, Frederic V. Hessman wrote:
> > Roy's low-level solution is fine as a VOEvent hack,
> 
> Not sure I like the word hack :)
> 
> > practical solution with the possibility of maintaining generality RIGHT
> > NOW is
> > <Reference type="ivoat:lightCurve" ucd="meta.code.url"
> > for which you simply have to check the type to understand very well.
> 
> This is certainly the reasoning behind the <Reference> element.
> 
> > Roy's example means knowing that the name "Light curve chart" is what to
> > look for, whereas looking for "ivoat:lightCurve" is just as easy and
> > perfectly general.
> 
> What does the code look like? Is it comparing the Reference type with known strings:
>    if Reference.type == "ivoat:lightCurve": handle the light curve
> Or is there a web service involved:
>    meaningObject = vocabularyLookup(Reference.type)
> in which case I ask what is in the meaningObject?
> 
> There are a very small number of vocabularies which
> > one could be looking for (here the IVOAT which, while not yet official,
> > DOES exist: see
> > http://www.astro.physik.uni-goettingen.de/~hessman/rdf/IVOAT/dict/L.html
> > and look for lightCurve).
> 
> OK, so we can look up in your vocab, and we find that Light Curve is related to other terms (magnitude ,maximum ,minimum ,period ,phase shift ,phase wave ,variable star ,velocity curve). I suppose we could also find out it is a subclass of Time Series, and maybe we already have a handler for those, so we can process the light curve with that. Is that the right idea?
> 
> > I have added (or? haven't checked the new VOEvent schema) the ucd
> > attribute for VO-compatibility. This could be the way to make the
> > "mime-sh" typing, e.g. by being able to use
> >
> > meta.code.xml
> > meta.code.rtml
> > meta.code.fits
> 
> This is exactly what Skyalert does. If a Param has ucd=meta.code.url, then it is handled differently in the presentation from other Params. The UCD is coerced to hold a mime type.
> 
> > but the other, better solution would be to be able to access
> 
> Why better?
> 
> > type="ivoat:RTML"
> > type="ivoat:FITSimage"
> > ...
> >
> > so that there is just one, simple, uniform means of identifying content.
> 
> But ucd is also "just one, simple, uniform means of identifying content". Isn't it?
> 
> > Roy's solution uses two XML constructs, 10 things to parse and 195
> > characters, mine one XML construct, 8 things to parse, and 174
> > characters (well, one does nominally need a reference to the IVOAT
> > namespace, but I'm sure Roy could hard-wire this one). ;-)
> >
> > Of course, as soon as I get a little bit of input, we can have a VOEvent
> > vocabulary covering everything Roy could possibly dream of needing in as
> > compact a set of terms as possible.
> 
> As I said above, the thinking behind the "type" attribute of the Reference is to make a place for semantic identifiers.
> 
> Roy