[fitsbits] start of Public Comment Period on the INHERIT convention

[Arnold Rots]

I am returning to Bill's sentiment - it saves me from rehashing the
arguments
(hm, this might be considered a form of inheriting these comments:-)

I think INHERIT is a bad idea, in short, because of the complications when
interpreting, modifying, and copying HDUs. As the standard currently stands,
each HDU is self-contained and I think that is a good thing.

As an aside, I wonder how many of the multi-image FITS files could be
combined
into an image cube.

Cheers,

  - Arnold

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Arnold H. Rots                                          Chandra X-ray
Science Center
Smithsonian Astrophysical Observatory                   tel:  +1 617 496
7701
60 Garden Street, MS 67                                      fax:  +1 617
495 7356
Cambridge, MA 02138
arots at cfa.harvard.edu
USA
http://hea-www.harvard.edu/~arots/
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On Tue, Jun 23, 2015 at 2:56 PM, William Pence <William.Pence at nasa.gov>
wrote:

> I share many of the concerns that others have expressed here about
> promoting the INHERIT convention into the FITS Standard.
>
> It seems to me that the motivation for using the INHERIT convention to
> save what typically amounts to less than a few 100K bytes of disk space per
> file is now greatly diminished from when it was first developed back in
> 1995, since the cost of disk storage has dropped so dramatically. Also,
> data providers are now much more comfortable with more efficient ways of
> packing multiple data arrays into a single binary table (which were only
> officially approved the year before in 1994), instead of writing each array
> as a separate image extension. Thus, I think it is questionable whether
> this convention continues to serve a useful purpose.
>
> Implementing this convention in FITS reading and writing software also
> seems to me to be a rather complex and somewhat ambiguous task.  It is not
> exactly clear what action should be taken with regard to preserving the
> inherited keywords during complex data processing operations where the
> values of some of the inherited keywords may be modified, or when copying
> an HDU which uses the INHERIT convention into another FITS file.  Because
> of these complexities, I have never attempted to support the INHERIT
> convention in the CFITSIO library.
>
> So far, all the comments about the INHERIT convention have been quite
> negative.  Does anyone want to offer any positive comments in support of
> incorporating this convention into the FITS standard?
>
> -Bill
>
>
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