[fitsbits] Bintable proposals

[Mark Calabretta]

On Wed 2001/11/21 13:44:39 CDT, William Pence wrote
in a message to: Mark Calabretta <Mark.Calabretta at atnf.CSIRO.AU>
and copied to: fitsbits <fitsbits at NRAO.EDU>

Dear Bill,

>very compelling case to do so.  In the case you cite, wouldn't it be much
>simpler to fix the files by substituting the correct value for NAXIS2 at the
>time the original file on tape is copied to another tape or to disk for
>distribution to general users?

Yes, this is the plan.

>  This seems like a much simpler solution than
>modifying the standard and all existing FITS readers to support files with
>NAXIS2 = -1.

In a sense this is a non-issue.

Firstly, there are few generic FITS interpreters, most are specific to the
data they're meant to analyse.  In particular, there's little chance that
any existing FITS interpreter will know what to do with raw pulsar pulse
profile data other than display it and that's probably not feasible anyway.
This is exacerbated by the limited standardization of header keywords/values,
so utilities like fv which can display and plot generic FITS data can't
interpret it fully.  Think of DSS data as a concrete example.

Secondly, special-purpose applications may use a generic IO library.  The
only one I know of is cfitsio but this can't handle tapes.  To use cfitsio
the file would have to be copied to disk and in the process it could be
fixed.

>It may be opening a can of worms to even bring this up, but there are many
>other requirements in the FITS Standard that seem rather artificial and
>could probably be relaxed with little or no effect on users and applications
>programs that read the files.  Some examples are:

These requirements may be annoying but they're not limiting (with the
possible exception of the 8-char keyword).

Cheers, Mark