Re: The Napkin Representation

From: Silvia Dalla <s.dalla-at-manchester.ac.uk>
Date: Tue, 3 Jul 2007 13:52:47 +0100 (BST)

Hi,

a few questions regarding the proposed new representation for time series.

1. Is this representation aimed at Time/Flux time series only, or should it be catering for time series of other quantities too? (orbits of objects have been mentioned by others earlier).
2. The simplest time series table consists of 2 columns only: one giving the time and one giving the observable that is varying in time. Is the new representation aimed only at this very simple time series? Or can the representation describe more complicated time series tables that have a time column and several columns for different observables?
3. Brad said:
   > (of course, I still don't see why a VOTable wouldn't work, but that was my
   > chief objection at the HTN/VOEvent meeting where The Napkin was wrote upon,
   > blessing us all with The Napkin Representation, but hey... :-) )
   

For those that were not at the HTN meeting it would be useful to know what are the objections against using a VOtable representation. I can see that in a VOtable a time column is somewhat anonymous and needs to be identified by UCD and unit (as discussed in Victoria). On the other hand there are several VOtable parsers that work and applications that know how to deal with VOTables.

I am not necessarily against a new representation but it would be useful have the use cases, applicability and advantages of it clearly spelled out.

best wishes,
Silvia

---

Silvia Dalla
School of Physics and Astronomy
University of Manchester
PO Box 88
Manchester M60 1QD
UK

Tel +44-161-306 8705
Fax +44-161-306 3922
------------------------------------

On Mon, 2 Jul 2007, Brad Cavanagh wrote:

> On Mon, 2 Jul 2007, Alasdair Allan wrote:
>
> > or alternatively like this,
> >
> > <TimeSeries type="delta_t">
> > <Meta>
> > <Param name="first" value="2007-07-01T21:44:00+0000" ucd="time.epoch;"
> > units="iso8601" />
> > </Meta>
> > <Data>
> > <Row number="1">
> > <Time units="s" uncertainty="0.5">0/Time>
> > <Flux type="mag" band="R" uncertainty="0.01">13.2</Flux>
> > </Row>
> > <Row number="2">
> > <Time units="s" uncertainty="0.5">35/Time>
> > <Flux type="mag" band="R" uncertainty="0.01">13.3</Flux>
> > </Row>
> > .
> > .
> > .
> > </Data>
> > </TimeSeries>
>
> Would a more compact version like this work?
>
> <TimeSeries type="delta_t">
> <Meta>
> <Param name="first" value="2007-07-01T21:44:00+0000" ucd="time.epoch;"
> units="iso8601" />
> <Time units="s" uncertainty="0.5" />
> <Flux type="mag" band="R" uncertainty="0.01" />
> </Meta>
> <Data>
> <Row number="1">
> <Time>0</Time>
> <Flux>13.2</Flux>
> </Row>
> <Row number="2">
> <Time>1</Time>
> <Flux>13.3</Flux>
> </Row>
> .
> .
> .
> </Data>
> </TimeSeries>
>
> ...i.e. set up default Time/Flux metainfo that would apply to all Time/Flux
> values in the Data section, allowing them to be overridden through explicit
> values in the Time/Flux sections in Al's quoted example?
>
> (of course, I still don't see why a VOTable wouldn't work, but that was my
> chief objection at the HTN/VOEvent meeting where The Napkin was wrote upon,
> blessing us all with The Napkin Representation, but hey... :-) )
>
> Cheers,
> Brad.
>
>
Received on 2007-07-03Z14:45:59