Re: ADQL v1.04 spec

From: Arnold Rots <arots-at-head.cfa.harvard.edu>
Date: Tue, 9 May 2006 15:33:17 -0400 (EDT)


Just a few quick comments.

I agree with Maria that the table alias always should be required in order to prevent confusion.

I agree with Yuji that the units of all parameters in the regions ought to be the same - also in order to prevent confusion. Besides, I don't believe that all queries will involve small circles.

And ADQL should be referencing STC version 1.30 at this point. Here is the correct syntax for a (large) circle. The following two strings are equivalent:

    Circle FK5 333.817116 55.832959 2.5
    Circle J2000 333.817116 55.832959 2.5 And this one is for all practical purposes the same:

    Circle ICRS 333.817116 55.832959 2.5

Here is the XML version of this circle:

<?xml version="1.0" encoding="utf-8"?>
<MyRegion xsi:type="STCRegion"

    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"     xmlns="http://www.ivoa.net/xml/STC/stc-v1.30.xsd"     xmlns:xlink="http://www.w3.org/1999/xlink"     xsi:schemaLocation="http://www.ivoa.net/xml/STC/stc-v1.30.xsd     http://www.ivoa.net/xml/STC/stc-v1.30.xsd">
<AstroCoordSystem xlink:type="simple"

      xlink:href="ivo://STClib/CoordSys#UTC-FK5-TOPO" id="UTC-FK5-TOPO"/>
<Circle coord_system_id="UTC-FK5-TOPO">
    <Center unit="deg">

      <C1>333.817116</C1>
      <C2>55.832959</C2>

    </Center>
    <Radius>2.5</Radius>
</Circle>

</MyRegion>

Of course, a more consistent use of STC would be to use the SearchLocation element defined in the schema...

Cheers,

Maria A. Nieto-Santisteban wrote:

> Dear all,
> 
> yet another unfinished version of the ADQL spec has been uploaded to the 
> the twiki
>  
>    http://www.ivoa.net/twiki/bin/view/IVOA/InterOpMay2006VOQL
> 
> See you soon
> 
> M.
> 
--------------------------------------------------------------------------
Arnold H. Rots                                Chandra X-ray Science Center
Smithsonian Astrophysical Observatory                tel:  +1 617 496 7701
60 Garden Street, MS 67                              fax:  +1 617 495 7356
Cambridge, MA 02138                             arots-at-head.cfa.harvard.edu
USA                                     http://hea-www.harvard.edu/~arots/
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Received on 2006-05-09Z21:34:11