[iaufwg] Call for vote on the new FITS Standard

[William Thompson]

I have done a final reading of the draft FITS standard preparatory to voting on 
it.  I am ready to vote in favor of this draft, except for one small omission 
having to do with the definition of the keyword CRPIXj.  Nowhere does it state 
that CRPIXj runs from 1 to N, instead of from 0 to N-1.  I've found that the 
distinction between these two cases trips up many novice FITS users, and is the 
most common mistake made.

I suggest the following revised wording, incorporating some of the wording from 
version 2.1b:

CRPIXj - [fl oating-point; indexed; default: 0.0]
Coordinate of the reference point along the pixel axis j.  This value is
based upon a counter that runs from 1 to NAXISj with an increment of 1 per 
pixel.  Note that the reference point may lie outside the image.

One might also want to add the phrase "as is the case for the default value", or 
something like it, to the last sentence, since 0.0 is just outside the image.

Bill Thompson

P.S.  There is an extraneous "the" in the first sentence of section 7.3.4 on the 
TDISPn keyword.


-- 
William Thompson
NASA Goddard Space Flight Center
Code 671
Greenbelt, MD  20771
USA

301-286-2040
William.T.Thompson at nasa.gov

(Note changed email address)