[fitswcs] coordinates by table lookup

[William Pence]

Peter Teuben wrote:
> 
> On Mon, 28 Oct 2002, William Pence wrote:
> 
> > Mark Calabretta wrote:
> > >
> > > On Fri 2002/10/25 15:29:00 -0400, William Pence wrote
> > > in a message to: fitswcs at NRAO.EDU
> > >
> > > > PS1_3 = 'wcsfile.fits'                    - in the same directory
> > > > PS1_3 = 'subdir1/subdir2/wcsfile.fits'    - in a subdirectory
> > > > PS1_3 = '/local/user/wcsfile.fits'        - absolute path
> > > > PS1_3 = 'ftp://nrao.edu/pub/wcsfile.fits' - URL
> > >
> 
> equally so, what about that other operating system that work
> backwards
> 
>         c:\subdir\wcsfile.fit
> 
> or any future OS.  Should one use a more generic URL-only syntax,
> since that is presumably more portable

One should use the URL 'forward slash' syntax on all platforms.  This is the
same syntax that is used in the Jennings et al. Hierarchical Grouping
Convention (http://adfwww.gsfc.nasa.gov/other/convert/group.html).  In
particular, see the discussion of the MEMBER_LOCATION field in that
document.  Also see Appendix 'I' where a syntax is suggested for specifying
the file name, extension type, extension name, and extension version all in
one string.

Bill
-- 
____________________________________________________________________
Dr. William Pence                          pence at tetra.gsfc.nasa.gov
NASA/GSFC Code 662         HEASARC         +1-301-286-4599 (voice)     
Greenbelt MD 20771                         +1-301-286-1684 (fax)