Re: String representations of numeric values

From: Francois Ochsenbein <francois-at-vizir.u-strasbg.fr>
Date: Fri, 21 Apr 2006 15:00:22 +0200

Dear VOTablers,

Thanks for all the comments -- the IVOA meeting is coming soon and this point of time/angle representations in VOTable could be one of the subjects if wished.

I would agree that the sexagesimal representation should be avoided in VOTable -- sexagesimal as well as iso dates would better be written as decimal degrees or MJD's, isn't it ?

As Clive mentioned, the VizieR output can display the coordinates in sexagesimal, e.g. from
http://vizier.u-strasbg.fr/viz-bin/votable?-source=USNO-B1&-c=0-90&-oc.form=sexa&-out.add=_RAJ,_DEJ

The conventions that are used there correspond to Mark's P2 suggestion:

>    P2. Modify the definition of the "units" attribute so that it is

> permitted to contain either a catstd-format unit string as at
> present, or a special representation string as in P1.
> We could possibly say that for numeric-valued columns it works
> as at present, but for string-valued columns it has the new sense.
> However one could conceive of a case where you want both
> representation and units (though I can't think of any actual
> examples), which would be problematic for this scheme.
and such units are "quoted" as "h:m:s" or "d:m:s", i.e. the FIELD definition contains unit="&quot;h:m:s&quot;" . In fact the "quoted" units were originally introduced to accept any non-standard unit. ================================================================================ Francois Ochsenbein ------ Observatoire Astronomique de Strasbourg 11, rue de l'Universite F-67000 STRASBOURG Phone: +33-(0)390 24 24 29 Email: francois-at-astro.u-strasbg.fr (France) Fax: +33-(0)390 24 24 32 ================================================================================
Received on 2006-04-21Z14:59:40