[NeXus-committee] Linking NXdata to NXdetector groups

[Ray Osborn]

On 4/26/04 13:02, "Akeroyd, FA (Freddie)" <F.A.Akeroyd at rl.ac.uk> wrote:

> Just a couple of points:
> 
> * In proposal 3 there does not have to be a one-to-one NXdetector and NXdata
> correspondence as stated in the summary - you could have multiple NXdata for
> a single NXdetector

I guess so, but won't you need to provide some way of associating axis
information within the NXdata group with the parent NXdetector group, such
as proposed in Proposal 3?

 e.g., how do you link the polar angle with distance in this example?

  <NXinstrument>
   <NXdetector>
      <NXdata name="Bank1">
         <data axes="polar_angle(1:i)">
         <polar_angle>
      </NXdata>
      <NXdata name="Bank2">
         <data axes="polar_angle(i+1:N)">
         <polar_angle>
      </NXdata>
      <distance(1:N)>
   </NXdetector>
</NXinstrument>

> * Proposal 1 is currently the only one that addresses non-detector axes in
> an NXdata group, but the same attribute linking scheme could be applied to
> all the other proposals for non-detector axes. The choice then is still
> about how and where you store the detector information.

That's true, but then we are explicitly using links to associate data, as
with Proposal 1.  Proposals 2 and 4 seem to be designed to work without
links.  

Regards,
Ray
-- 
Dr Ray Osborn                Tel: +1 (630) 252-9011
Materials Science Division   Fax: +1 (630) 252-7777
Argonne National Laboratory  E-mail: ROsborn at anl.gov
Argonne, IL 60439-4845