UCD stat quantities P/S question

[Mark Taylor]

Mireille,

thank you for this response; but actually the point made by Francois
makes a lot of sense too - if it's a mean/median/min/max of (e.g.)
a magnitude, you can still treat it as a magnitude, but if it's
a stdev/variance that's probably a bad idea.

Now I have two answers I can choose the one I like :-)
For now I will go with what's written in the document and
avoid writing something like phot.bol.mag;stat.stdev.
Cons: I can't mark something as a stdev of a known semantic quantity
Pros: downstream software won't be encouraged to do something inappropriate

Mark

On Thu, 21 Jul 2016, Mireille Louys wrote:

> Hi Mark ,
> 
> Thanks for pointing this error.
> 
> Yes all these terms should be used similarly and have a S status
> 
> explaining the secondary position in the UCD strings.
> 
> Sorry for that.
> 
> Mireille
> 
> 
> Le 20/07/2016 à 13:38, Mark Taylor a écrit :
> > Dear semantics,
> >
> > I have a question about some of the stat.* UCDs.
> >
> > I see in the UCDlist document:
> >
> > S | stat.max
> > S | stat.mean
> > S | stat.median
> > S | stat.min
> >
> > but
> >
> > P | stat.stdev
> > P | stat.variance
> >
> > Why are max/min/mean/median designated as Secondary but
> > stdev and variance as Primary?  I can imagine wanting to use,
> > e.g. both
> >
> >     pos.parallax;stat.mean
> >
> > and
> >
> >     pos.parallax;stat.stdev
> >
> > but the second is apparently not allowed.
> > I was expecting all of these to be marked S or maybe Q.
> >
> > Thanks for enlightenment,
> >
> > Mark
> >
> > --
> > Mark Taylor   Astronomical Programmer   Physics, Bristol University, UK
> > m.b.taylor at bris.ac.uk +44-117-9288776  http://www.star.bris.ac.uk/~mbt/
> 
> 

--
Mark Taylor   Astronomical Programmer   Physics, Bristol University, UK
m.b.taylor at bris.ac.uk +44-117-9288776  http://www.star.bris.ac.uk/~mbt/