[Nexus] NOBUGS and instrument formats

[Ray Osborn]

I notice that there are a few presentations concerning the definition of
instrument formats using NeXus, which is the weakest part of the standard at
the moment.  I would like to encourage those making presentations or posters
to review the latest developments recorded on the web site about this issue,
especially the use of XML for formalizing those definitions.  In particular,
check out 

<http://www.neutron.anl.gov/nexus/NeXus_contents.html#Glossary>

where the XML versions of the different data groups is currently given.  The
actual group definitions, e.g. for NXsample, can still be debated, but this
should be the starting point.  As much as possible, we would like actual
instrument definitions to subclass the standard groups, defining what is
essential, optional, etc.  If it is not possible, we should discuss on this
mailing list whether the base definitions need changing.

<http://www.neutron.anl.gov/nexus/NeXus_metaformat.html>

where the XML metaDTD format is defined.  Again, if you have encountered
limitations of this definition, then please discuss it here.

To summarize, if you have serious differences with any of the web
definitions, please raise it on this mailing list.  I welcome a debate on
these issues at the conference, particularly at the break-out session, but
it would be helpful to have a common starting point for that debate. It
would be worth airing some of those problems now so that we don't confuse
outsiders.  

By the way, if you have example NeXus files containing your proposed
definitions, the NXtoDTD converter included in the latest API will make an
unannotated XML definition file.

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