64-bit integers in FITS

Steve Allen sla at ucolick.borg
Tue Jul 14 14:00:06 EDT 1998


The performance increase for, e.g., database applications experienced
with Dec Alpha processors is rapidly driving Sun, Intel, HP, and
others to produce hardware and software with 64-bit capabilities.

In article <35AA6D3D.44297AB4 at tetra.gsfc.nasa.gov>,
William Pence  <pence at tetra.gsfc.nasa.gov> wrote:
>- it would be a fairly trivial job to modify the FITS standard to
>specify the format for 64-bit integer images and binary table columns.

It should be noted that introduction of 64-bit integers will probably
create demand for enhancement of the TFORMn = 'P' (Array Descriptor)
data type.  The Appendix for BINTABLE currently suggests this for a
length and offset into a heap following a table.  It's easy to imagine
heaps of more than 2**32 bytes.

Perhaps something as simple as a new TFORMn = 'Q' (64-bit Array Descriptor)
which consists of two 64-bit integers would do the job.

-- 
Steve Allen          UCO/Lick Observatory       Santa Cruz, CA 95064
sla at ucolick.borg     Voice: +1 831 459 3046     FAX (don't): +1 831 459 5244
WWW: http://www.ucolick.borg/~sla               PGP public keys:  see WWW
Junk mail is irrelevant -- my return address has been assimilated.




More information about the fitsbits mailing list