Re: [h5md-user] [h5md-commit] [SCM] master, updated. c234149781bfa9f5dc81aa139038e7dc6689b64d

[Felix Höfling]

Am 20.06.2013, 17:02 Uhr, schrieb Peter Colberg  
<address@hidden>:

> On Thu, Jun 20, 2013 at 02:24:02PM +0200, Pierre de Buyl wrote:
> > > Making it optional would be possible, but I don't favour it. The
> > > question then is how /trajectory and /observables differ at all and
> > > why the two groups need to be distinguished and specified.
> >
> > Before going further, I have a point for this (traj vs obs) that I did  
> > not make
> > in my previous messages that helps me to make the distinction:
> >
> > /trajectory : time dependent data with storage of order N
> > /observables: time dependent data with storage of order 1
>
> That is my thinking as well. In other terms:
>
> /trajectory : time evolution of microscopic system-state
> /observables: time evolution of macroscopic system-state
>
> Peter

Good, so we all agree on this point. I tried to make a similar distinction  
some time ago, in the current draft it reads:

"System trajectories, or more generally, time-dependent information for  
each particle, are stored in the /trajectory group."

"Macroscopic observables, or more generally, averages over many particles,  
are stored as time series in the root group /observables."

If you feel that the distinction in terms of storage or  
microscopic/macroscopic should be made more explicit, you are welcome to  
rephrase.

BTW, in the text we may move up the section on the box specification since  
it is needed for the trajectory group. This way, we would first specify  
how to store data in general (a short paragraph on fixed-in time data may  
be added), then the box (which appears to be the most delicate issue), and  
finally the trajectory and observables groups.

Best regards,

Felix