[AstroPy] Re: HIERARCH

Perry Greenfield perry at stsci.edu
Wed Mar 30 20:09:48 CST 2005


On Mar 30, 2005, at 8:24 PM, Joe Harrington wrote:

>> add (and not in the greatly distant future either).
>
> That's good to hear!
>
>> The primary issue is whether or not to automatically invoke this
>> convention when updating a header that isn't already using it.
>
> I am not intimate with the HIERARCH extension, but I don't think that
> there is any difference between a header that has the extension but
> doesn't happen to have any HIERARCH keywords in it, and one that
> doesn't have the extension.  If that's the case, and a user adds a
> HIERARCH keyword to a non-HIERARCH header, you can assume they know
> what they are doing and enable it without some funky switch (it won't
> happen by accident).  If it's not the case, clearly you don't want to
> write HIERARCH-enabled headers for all files.
>
I'm not so sure. Users can mistakenly write (through typos or use of 
variables) keywords that are longer than 8 characters without realizing 
they doing so. In such cases it is probably a good thing to raise an 
error. Basically you have two different situations, one where users 
want a strict fits header, and expect to be warned when they have 
non-conforming keywords, and the other case where they don't want to be 
bothered when they are writing long keyword names. So this situation is 
murkier from the point of view of what should be done. You know what 
you want, but it isn't necessarily what other users want for default 
behavior.

Perry




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