[fitsbits] 64-bit integers

[William Pence]

Thierry Forveille wrote:
> 
> William Pence writes:
>  > The question I would like to raise is, should a proposal to support 64-bit
>  > integers in FITS now be drafted and submitted to the 3 regional FITS
>  > committees for their consideration?  Are there any compelling reasons not to
>  > do this now?
>  >
> Could you come up with a few practical examples that actually demand the
> dynamics of 64-bit integers?

Yes.  With the help of some of my colleagues here I've tried to assemble the
arguments in favor of adding 64-bit integers to FITS into a document that is
available in html or postscript format at:

http://heasarc.gsfc.nasa.gov/docs/heasarc/fits/64bit/64bit.html 
http://heasarc.gsfc.nasa.gov/docs/heasarc/fits/64bit/64bit.ps

This is still a draft document, so any comments or suggestion are welcome.

In brief, the document lists the cases we could think of that might require
using 64-bit integers.  Please let me know if you think of other cases.

The document also discusses the potential cost of retrofitting existing
software systems to support the new data type, and lists some reasons why
this effort may not be as large as some would fear.

-Bill Pence
-- 
____________________________________________________________________
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)