[AstroPy] fits coordinate system keyword

[Thomas Robitaille]

Hi Paul,

Just out of curiosity, was RADECSYS ever a keyword in the FITS standard,
as opposed to RADESYS? (which is the currently valid keyword). If so, in
what version of the standard?

Cheers,
Tom

Paul Kuin wrote:
> Actually, one of the basic tenets of FITS is to be completely backward
> compatible, so any keyword that was valid in the past is valid now. So
> that warning is also inaccurate. If it was standard, it still is, and
> ever will be.
> 
> 
> 
> On Mon, Oct 5, 2015 at 5:25 PM, Erik Bray <embray at stsci.edu
> <mailto:embray at stsci.edu>> wrote:
> 
>     On 10/05/2015 12:17 PM, Paul Kuin wrote:
> 
> 
> 
>         I am getting very annoyed of the warning that keeps popping up
> 
>         WARNING: FITSFixedWarning: RADECSYS= 'FK5' / default
>         RADECSYS is non-standard, use RADESYSa. [astropy.wcs.wcs]
> 
>         I'm not sure when the FITS standard changed, but MOST legacy
>         fits files (I use)
>         will have the RADECSYS keyword. It works, and I do not see why
>         someone felt the
>         need to keep this warning being popped up all the time.
> 
> 
>     Probably as a warning to remind authors of new files that they
>     shouldn't be using that keyword.  I don't know that it necessarily
>     needs to be displayed every time reading in a WCS except maybe to
>     head off cases of ambiguity.  But I don't know this particular issue
>     well enough to be sure if the warning is appropriate in all cases or
>     not.
> 
>         I think that by default it should be off.
> 
>         Since you all probably think it should be there, I would like to
>         know how to
>         turn it off ?  any suggestion on how to do that?
> 
> 
>     http://docs.astropy.org/en/stable/warnings.html
> 
> 
>     Erik
> 
>     _______________________________________________
>     AstroPy mailing list
>     AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     https://mail.scipy.org/mailman/listinfo/astropy
> 
> 
> 
> 
> -- 
> 
> * * * * * * * * http://www.mssl.ucl.ac.uk/~npmk/ * * * *
> Dr. N.P.M. Kuin      (n.kuin at ucl.ac.uk <mailto:n.kuin at ucl.ac.uk>)      
> phone +44-(0)1483 (prefix) -204927 (work)
> mobile +44(0)7806985366  skype ID: npkuin
> Mullard Space Science Laboratory  – University College London  –
> Holmbury St Mary – Dorking – Surrey RH5 6NT–  U.K.
> 
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> https://mail.scipy.org/mailman/listinfo/astropy