[Nexus] XML questions

[Ray Osborn]

On 2002/12/06 8:40, "Johnson, G (Greg)" <G.Johnson at rl.ac.uk> wrote:

> Am I correct in thinking that a correct XML Schema would be a useful way of
> validating _all_(HDF4/5 & XML) NeXus files?

Hi Greg,
I was aware that current XML development effort was directed towards
schemas, although I confess that I hadn't had the time to look into them
closely.  You prompted me to read a comparison of DTD's and schemas, and you
are right that schemas have the advantage of specifying data types.
Namespace support may also be valuable in the future.  Actually, I got the
impression that it would be easier to convert a NeXus metaDTD file to a
schema file than to a DTD file.
 
> Due to my inexperience with XML, I'm sure the Schema could use some work and
> perhaps some design changes.  But for now, I think it works.  It seems to me
> that using NeXus XML lowers the barrier to 'full' NeXus (HDF) usage - for
> small data files, the XML tag overhead is not huge, and the benefits of
> being semi-human readable are a good thing for scientists who want to be
> able to put their data into Excel without using a special extracter.

That seemed to be one of the messages from NOBUGS.  There is increasing
support for the idea of creating a version of the NeXus API that reads and
writes XML files, although we don't know who will do the work yet.
 
> I'd be interested in hearing other people's feedback about XML and Schema -
> it seems like the email list is very quiet.  Are all the real discussions
> going on in private email?
> 
> With regards,
> greg
> 
> PS if anyone wants to have a look at the Schema, let me know.  Perhaps we
> can stick it on the website, or something.

I'd be happy to if you send it to me.  In fact, we are looking into setting
up a Wiki or other type of message forum site to make it easier for people
to post things directly on to the web.

Best 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