[NeXus-committee] NeXus base class discussions

[Ray Osborn]

On 4/16/04 11:53, "Steve King" <smk at isise.rl.ac.uk> wrote:

> Also, having just read Ray's posting, I'm not sure we will be doing
> ourselves any favours by insisting on polar and azimuthal angles.  Two
> theta might not be very explicit, but it is very widely used.  It should be
> accommodated, somehow..., for those that would rather use it.

In my view, that's just not an option if NeXus is to be a general standard.
People are already complaining that there are too many items defined in the
NeXus standard.  We will have a whole lot more if we allow a dozen aliases
for every item.  A standard has to choose a single name out of all the
available options, not allow all of them.

We are dealing with educated scientists, all of whom should understand what
a polar angle is.  There will be a learning period when we have to explain
to them that NeXus assumes a coordinate system where the z-axis is the
nominal beam direction.  However, most people would only have to be told
that once, and polar_angle is a lot less cryptic than phi or nu once they
understand the principle.

Of course, people are free to use whatever they like in their own private
NeXus files that they never expect anyone else to read.

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