Empty TD element wording

[Ed Shaya]

Mark Taylor wrote:

>On Wed, 21 Jun 2006, Ed Shaya wrote:
>
>  
>
>>Mark Taylor wrote:
>>
>>    
>>
>>>On Wed, 21 Jun 2006, Clive Page wrote:
>>>
>>> 
>>>
>>>      
>>>
>>>>have seen little evidence of need for more than one.  I think it would be 
>>>>more productive to work on a standard way of expressing the notion of 
>>>>upper (or lower) limits - something which is so far missing from most 
>>>>astronomical formats.
>>>>   
>>>>
>>>>        
>>>>
>>>VOTable does provide such limits (MIN and MAX subelements of VALUES),
>>>but I don't get the impression they are widely used (I'm afraid none
>>>of my software writes them or does anything with such elements if
>>>they are present).
>>>
>>> 
>>>
>>>      
>>>
>>I don't think that those are meant to be used as upper limit or lower 
>>limit measurements.  They are metadata meant to indicate highest and 
>>lowest valid numbers for the Field.
>>
>>Ed
>>    
>>
>
>Ed,
>
>I think you can use it for either, according to the value of the 
>VALUES type element.  Sec 4.6 says:
>
>   The scope of the domain described by the VALUES element (and by its
>   MIN, MAX and OPTION sub-elements) can be qualified by type="actual",
>   if it is only applicable to the data enclosed in the parent TABLE; the
>   domain of a valid RA in the example above has the default type="legal"
>   qualification.
>
>Mark
>
>  
>
When you want to supply the min and max of the list of numbers actually 
in a Table/Field, one use's "actual".  This is still not an upper or 
lower limit.  One would need an optional attribute in the TD, as in
<TD limit="upper">12.3</TD> to specify  u.l. or l.l.

Ed