ADQL XMATCH

[Markus Demleitner]

Hi Alex,

On Tue, Feb 09, 2016 at 07:55:33PM +0000, Alex Szalay wrote:
> I agree with Tom, that this approach is completely flawed.  The
> notion of a spatial crossmatch is not a logical value, but it is a
> posterior likelihood, or at best a Bayes factor which can (and
> should) be combined with additional attributes like shape, flux,
> color etc.

I always like it when something is based on a good theory, and
sometimes a good theory explains why there appear to be no satisfying
solutions to an existing problem[1].

So: based on a probabilistic analysis of crossmatching, do you have a
proposal for how these concepts could be mapped into ADQL language
elements?

Thanks,

        Markus


[1] which here is: everyone wants to do crossmatches, and what ADQL
right now offers is the highly unpopular (and also boolean)

1=CONTAINS(POINT('ICRS', ra, dec), CIRCLE('ICRS', basera, basedec))