Re: [h5md-user] fields of observable group

[Pierre de Buyl]

> > I have one objection: it might be of advantage to have some
> > parameters standardised, e.g., the box size. Otherwise, an H5MD
> > reader could not retrieve the box size from an H5MD file without the
> > trajectory group. (And the box volume is certainly an interesting
> > quantity independent of the trajectory.)
>
> That is not an objection, but an endorsement of my proposal ;-).
>
> We would definitely not want to mix non-specified (i.e. program
> dependent) and specified parameters in the same group. This is
> why it is a good idea to give program-dependent parameters
> a program-dependent group name from the beginning.
Ok, then the idea would be to have no parameters group but the  
specification would suggest that programs creating H5MD files create  
a "program_name" group for that (or other) purposes.
An observable with the box size as a function of time for variable  
size simulations would fit this need, also.

> With regard to the box size, should we postpone this to version 0.2?
I'd go with either a very simple definition (like min/max or min/ 
length attributes to the position dataset) or none for 0.1.

Pierre