Transf WD Where are the axis

[Laurent MICHEL]

David,

My feeling is, like Gerad said, that the mappings should be more 
explicit in the model. I missed that point on March 10.


Le 02/04/2020 à 16:55, David Berry a écrit :
> I agree maybe we've been a bit too free and easy with the use of the
> word "axis" in the document. I many cases we should probably replace
> "axis" with "mapping input" or "mapping output". 

Would be better but likely not enough (IMO).

 >
The definition of
> which physical quantities are associated with each input and output is
> provided by the TransformSet.
Do you mean TCompound?

I'm may be confused with the scope of the model.
In FITS-WCS there is no explicit binding between e.g. image pixels and 
WCS keywords.
WCS just says that this image has been generated by applying that 
transformation. If the scope of TRANSF is to do the same in VOTables, it 
is fine.
 From another hamd, if the ambition of Transf was to be able to model 
workflows (sequence of transformations), we would have to be able to say 
what kind of input data are expected by a given operation and to which 
data are produced. If we assumed that all transformed things are 
matrices, just specifying the input/output dimensions could do the job 
does it?

Laurent

> 
> David
> 
> 
> On Thu, 2 Apr 2020 at 14:01, Gerard Lemson <glemson1 at jhu.edu> wrote:
>>
>> Hear, hear.
>> See my comments in http://mail.ivoa.net/pipermail/dm/2020-March/005994.html and http://mail.ivoa.net/pipermail/dm/2020-March/006000.html.
>> Though there I propose a domain model view of the effort, I think that including axes explicitly in the model may well simplify it by making relations more explicit.
>> Cheers
>> Gerard
>>
>>> -----Original Message-----
>>> From: dm-bounces at ivoa.net <dm-bounces at ivoa.net> On Behalf Of Laurent
>>> MICHEL
>>> Sent: Thursday, April 2, 2020 8:42
>>> To: dm at ivoa.net
>>> Subject: Transf WD Where are the axis
>>>
>>>
>>> Dear,
>>>
>>> Comment #1:
>>>
>>> I've a little trouble with the concept of axis.
>>> Section #2 mention tens of time operations on axis, but there nothing in the
>>> model referring to axis.
>>>
>>> The Axis place in the model should be clarified.
>>>
>>> LM
>>> --
>>> ---- Laurent MICHEL              Tel  (33 0) 3 68 85 24 37
>>>        Observatoire de Strasbourg  Fax  (33 0) 3 68 85 24 32
>>>        11 Rue de l'Universite      Mail laurent.michel at astro.unistra.fr
>>>        67000 Strasbourg (France)   Web  http://astro.u-strasbg.fr/~michel
>>> ---
>>

-- 
---- Laurent MICHEL              Tel  (33 0) 3 68 85 24 37
      Observatoire de Strasbourg  Fax  (33 0) 3 68 85 24 32
      11 Rue de l'Universite      Mail laurent.michel at astro.unistra.fr
      67000 Strasbourg (France)   Web  http://astro.u-strasbg.fr/~michel
---