[iaufwg] approval of the "column limits" convention

[William Pence]

Dear IAU FITS Working Group members,

The public comment period on the first convention to be submitted to our 
"Registry of FITS conventions" has now ended (see copy of message below). 
This is a simple convention for specifying the minimum and maximum values in 
a table column.   According to the rules that we established (see 
http://fits.gsfc.nasa.gov/fits_registry_rules.html) this convention will be 
automatically entered into the registry unless any FWG member raises an 
objection within the next 3 weeks.  A formal vote will only be taken if 
there are any objections; in that case a simple majority of votes will be 
required to accept the convention into the Registry.

For the record, I received 2 comments during the comment period:

1.  Richard McMahon wrote: "It might be worth specifying whether these 
limits can be floating point or not.".

In response, I added this sentence to the description of this convention: 
"These keywords should have the same data type as the physical values in the 
associated column (either an integer or a floating point number)."

2.  Tim Pearson pointed out an apparent semantic inconsistency in that (and 
I am paraphrasing here) the TLMINn and TLMAXn keyword define the "legal 
range" of values, yet it is permissible (and hence, "not illegal") to have 
values in the column that are outside this range.

I responded that while I see his point, I think the meaning of the term 
"legal" in this case will be understood by users and is not too confusing. 
In any case, the letter 'L' in the TLMINn and TLMAXn keyword stands for 
"legal", and has already been in widespread use for more than 10 years, so 
it is too late to change this wording now.


Unless I hear any further comments or objections from any of you, this 
convention will be officially entered into the Registry in 3 weeks, on 4 
October.

On a related note, please consider writing up a description of other FITS 
conventions and submitting them to the Registry.   Let me know if I can be 
of any assistance in preparing the documents or sample FITS files.  There is 
already one other convention in the pipeline (A "Foreign File Encapsulation" 
convention, submitted by Rob Seaman) that will be starting it's public 
comment period soon.

regards,
Bill


William Pence wrote:
> This is a reminder that the public comment period on the FITS "Column 
> Limits" keyword convention will close on Monday, Sept 11.  This is the first 
> convention to be submitted to the new Registry of FITS Conventions that has 
> been established by the IAU FITS Working Group.  Further information about 
> this convention, and the FITS Registry, are contained in the original 
> announcement which is copied below.
> 
> Bill Pence
> 
> -------- Original Message --------
> Subject: [fitsbits] Start of "column limits" public comment period
> Date: Fri, 14 Jul 2006 13:43:28 -0400
> From: William Pence <pence at milkyway.gsfc.nasa.gov>
> Organization: HEASARC
> To: FITSBITS <fitsbits at nrao.edu>
> 
> This is to announce the start of the Public Comment Period on the FITS
> "Column Limits" keyword convention that has been submitted for inclusion in
> the "Registry of FITS Conventions" maintained by the IAU FITS Working Group.
>    A document describing this convention, and a sample FITS file that uses
> it, are available for public review and comment from the FITS registry web
> page at
> 
> http://fits.gsfc.nasa.gov/fits_registry.html
> 
> This is a fairly simple convention that defines 4 keywords that can be used
> to specify the allowed minimum and maximum values in a table column (TLMINn
> and TLMAXn) and the actual minimum and maximum values in the column (TDMINn,
> and TDMAXn).
> 
> The Public Comment Period normally lasts 30 days, but since this is a
> vacation period for many, the comment period will remain open until
> mid-September.  Any major comments should be posted here on the FITSBITS
> mail exploder.  Minor or typographical issues can be sent directly to the
> person that submitted the convention to the registry (myself in this case).
> 
> Because this is the first convention to be submitted to the Registry, it may
> be useful to summarize the purpose of the registry and the public comment
> period.  The IAU FITS Working Group set up the registry to provide a central
> and authoritative place for documenting the many FITS conventions that have
> been developed by various groups over the past 25 years.  Many conventions
> are now in use in FITS files, yet it can be difficult to find documentation
> on how to use and interpret them.  Anyone may submit a convention to the
> registry; all that is needed is a brief document that describes the
> convention and a sample FITS file that uses it.
> 
> The submitted material is made available for public comment on the FITSBIT
> email list (and the associated sci.astro.fits newsgroup). The main purpose
> of this public comment period is to consider whether the submitted material
> is as clear and complete as possible.  Comments about the actual
> implementation of the convention or suggestions on ways to improve it are
> also welcome, but if the convention is already in wide-spread use it may not
> be possible to change the implementation of the convention.
> 
> Bill Pence
> (on behalf of the IAU FITS Working Group)


-- 
____________________________________________________________________
Dr. William Pence                       pence at milkyway.gsfc.nasa.gov
NASA/GSFC Code 662       HEASARC        +1-301-286-4599 (voice)
Greenbelt MD 20771                      +1-301-286-1684 (fax)