[iaufwg] Call for vote on the new FITS Standard
Steve Allen
sla at ucolick.org
Tue May 6 19:20:26 EDT 2008
On Tue 2008-05-06T16:11:22 -0700, Dick Shaw hath writ:
> While it may be possible to find ways to improve the wording still further in
> the 3.0 draft, IMHO the time for that has come and gone, save for serious
> technical flaws. In any case, the suggested change is not correct in the
> general case: the index in question, j, runs from 1 to WCSAXES.
True for the value of j
The array index referred to by CRPIXja runs from 1 to NAXISj - 1.
This subtlety of array index numbering was a significant point of
argument during the development of WCS papers 1 and 2. Those
discussions resulted in that explanatory paragraph and the inclusion
of footnote 1 in WCS 1. (Alas that the string CRPIX did not get
included within that paragraph to make the hunting easier.)
If such words are not in the 3.0c draft then the only way for someone
to know the numbering is to find WCS 1 or the original Wells paper.
I support William Thompson's suggestion that this is important enough
to fix.
--
Steve Allen <sla at ucolick.org> WGS-84 (GPS)
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