[fitsbits] structurally compliant FITS

[Mark Calabretta]

On Mon, 29 Jun 2015 10:44:49 +0000
<patrick.wallace at stfc.ac.uk> wrote:

> In my view the distinction between standard FITS and optional
> conventions is so crucial that there should be separate documents
> (or perhaps "should have been" if it is now too late).

Conventions have been kept separate from the standard and documented
at http://fits.gsfc.nasa.gov/fits_registry.html

> The standard should contain what FITS readers/writers *must*
> implement;  the other document, perhaps called a "style guide",
> would set out and name the various well-established conventions
> that implementors may or may not provide for.

An excellent operational definition, though some qualification is
needed.

In practice, no single software package implements the whole of the
FITS 3.0 standard.  So, whereas cfitsio does all of the i/o aspects,
WCSLIB does all of the WCS.

Particular data reduction or analysis packages may implement only
so much of the standard as pertains to their particular data type
(images, spectra, visibility data, pixel lists, etc.) and still
claim conformance.

Regards,
Mark Calabretta