[Nexus] Basic questions about application definitions

[Pete Jemian]

Good question.

On 2/12/2015 10:39 AM, Andrew GOETZ wrote:
> A second question we had is that the way the application definitions are
> defined today implies they duplicate data in the file instead of linking
> to it. This is because they insist on creating NXsubentry. Please
> correct me if we have misunderstood the use of NXsubentry.

At the 2014 Code Camp, we discussed whether application definitions must 
always be used as NXsubentry or might they be used in place of NXentry. 
  The point was raised because of this specific confusion, as you voiced it.

The answer is that an application may be used as either NXentry or 
NXsubentry.  The latter usage is obvious for a multi-technique 
instrument such as SAXS/WAXS.  But a single-technique instrument should 
not be required to place an application definition as a child of the 
NXentry.


 > This begs the question : how many sites are using the Application
 > definitions and how do you get around the bugs?

Use of the Application definitions is growing.  I'm not sure how we can 
accurately measure the use across the community.

Bugs should be reported to the NeXus forum.  Thanks for your report!

The bug you reported (took me a few minutes to see it) is a common typo 
and will be resolved by the one who writes the file, either by changing 
the text of the link or changing the name of the detector group.  Or the 
data file stays in error until someone notices.



Pete

-- 
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Pete R. Jemian, Ph.D.                <jemian at anl.gov>
Beam line Controls and Data Acquisition, Group Leader
Advanced Photon Source,   Argonne National Laboratory
Argonne, IL  60439                   630 - 252 - 3189
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    Education is the one thing for which people
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