Thanks, Ros. I had a feeling the CF checker was being precise, I just
couldn't figure out why it wasn't happy. Mystery solved!
Does anyone know if there is any reason why Appendix A limits comments
to non-coordinate variables? That seems ... unusual. I don't recall any
threads discussing this, but I might have missed it.
Is there a better way to describe how coordinate values were determined?
For
example, I'd really like to convey the fact that there are N meters of
assorted
hardware between an instrument and the surface, when the depth value is not
a measured variable, or that the X,Y values are not true points, when we
have
only the position of the anchor on a surface mooring. I'm also supplying a
watch circle radius, but that's not part of any standard.
Cheers - Nan
On 4/23/12 10:51 AM, r.s.hatcher at reading.ac.uk wrote:
> Hi Nan,
>
> The CF checker is producing the INFO message because according to
> Appendix A the "comment" attribute can be attached to either a
> (G)lobal variable or a (D)ata variable containing non-coordinate data.
>
> This is just an informational message alerting you to the fact that
> you may be using the attribute incorrectly. As far as I am aware there
> is nothing to stop you using the comment attribute on a coordinate
> variable (hence the INFO message not WARNING or ERROR) - it just isn't
> a standard use of it.
>
> Regards,
> Ros.
>
>
> On Apr 23 2012, Nan Galbraith wrote:
>
>> Hi all -
>>
>> I've got a question about the correct use of comments in CF.
>>
>> In chapter 2 of the spec (actually, 2.6.2. Description of file
>> contents) the term comment is defined this way: "Miscellaneous
>> information about the data or methods used to produce it."
>>
>> I'm using comments to describe some of my coordinate variables:
>> DEPTH:comment = "approximate instrument depth" ;
>> LATITUDE:comment = "surveyed anchor position" ;
>> LONGITUDE:comment = "surveyed anchor position" ;
>>
>> This SEEMS like what this attribute is meant to do; it gives an idea
>> of the coordinates' accuracy, or lack thereof, which can't really
>> be quantified.
>>
>> These produce a warning from the NCAS-CMS (NERC) CF checker:
>> ' INFO: attribute 'comment' is being used in a non-standard way.'
>>
>> Isn't this the correct use of the comment field? Is there some
>> prohibition
>> against this, or is there another use of the comment attribute, that
>> restricts its 'normal' use? I've pored over the spec, and can't figure
>> out why this could be considered 'non-standard'. Any ideas? Am
>> I missing something?
>>
>> Thanks -
>>
>> Nan
>>
>>
>
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>
--
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* Nan Galbraith Information Systems Specailist *
* Upper Ocean Processes Group Mail Stop 29 *
* Woods Hole Oceanographic Institution *
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Received on Mon Apr 23 2012 - 09:19:53 BST
