[WP3] Re: AssociateList question

[Kor G. Begeman]

Folks,

The function Jan asked for is now implemented in AssociateList. That is, 
you can now specify the area of the sky on which you want the 
association to be done. How to do this is documented in Manual.pdf but 
also below. The implementation of this was possible without slowing down 
the SQL query. I hope this helps Jan do his thing with the AssociateList 
class.

If any of you have suggestions for improvement or new functionality,
please let me know (via the wp3 mailing list).

Cheers,

Kor

Kor G. Begeman wrote:
> Jan,
> 
> I just had a look at the code and in principle your way to do this will 
> NOT work. It will work for finding the singles inside the area but for 
> finding pairs no area restriction is used since we only look for matches 
> which will always be in the overlaping parts of two images. I will have 
> to modify the queries for this which is of cource not a problem but will 
> take somewhat longer than just a few minutes. What I am thinking of is 
> to add an extra function to AssociateList so that you can limit the 
> search area. You would do this then as follows:
> 
> AL = AssociateList()
> AL.set_search_distance(2.0)
> AL.sourcelists.append(SL1)
> AL.sourcelists.append(SL2)
> AL.set_search_area(llRA,llDEC,lrRA,lrDEC,ulRA,ulDEC,urRA,urDEC)
> AL.make()
> 
> 
> The modified queries which take into account the search area might be 
> mucht slower than the one I am using now, but experimenting with them 
> might help.
> 
> What do you think of this?
> 
> Ciao,
> 
> Kor.
> 
> Jan Snigula wrote:
> 
>> Hello Kor,
>>
>> I've got a short question about the behaviour of AssociateList. I need to
>> associate different sourcelists against one common "master" list. In
>> principle no problem, but the overlap areas might be different. So if I
>> calculate the overlapping area between all the fields (easy) and set the
>> coord ranges of the master list to these values, will AssociateList then
>> just use these values, and then associate only in the common overlap
>> region?
>>
>> Thanks,
>>
>> Jan
> 
> 

-- 

Dr. K.G. Begeman
OmegaCEN
Kapteyn Institute
University of Groningen
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