Re: [h5md-user] boundary conditions (again)

[Pierre de Buyl]

Hi,

I sent this off the list by mistake.

On Thu, Aug 01, 2013 at 02:06:51PM +0200, Pierre de Buyl wrote:
> On Wed, Jul 31, 2013 at 11:57:49AM +0200, Olaf Lenz wrote:
> > On 07/31/2013 11:08 AM, Felix Höfling wrote:
> > > Hence, I suggest that the boundary type "nonperiodic" is replaced 
> > > either by the empty string or by "none" (synonym for
> > > "unspecified"). In this case, the edge specification along this
> > > axis is not relevant. Even more, if all axes have "none", "edges"
> > > could be dropped at all ...
> > 
> > Yes, good idea!
> 
> edges and offset then :-)
> 
> > > What would be the impact of a missing box on visualisation tools?
> > 
> > No problem for VMD, and I cannot imagine this to cause problems anywhere
> > else. When no box is given, you can just not display a periodic box, and
> > not display periodic images. Which makes sense, somehow.
> > 
> > > NB: actually, it would be more correct to speak of the boundary 
> > > condition of the box _faces_ instead of axes or directions. On the 
> > > other hand, to opposite faces will most likely have the same type
> > > of BC.
> > 
> > I disagree. The nice thing about periodic boundaries is that there are
> > no faces and no position that is distinguished from any other position.
> > Talking of faces implies otherwise.
> > However, you are of course right that the coordinate axes do not
> > necessarily have to do anything with the axes of the boundaries. I
> > haven't seen anything else, though.
> 
> There will be less confusion if we mention a boundary per dimension, as is the
> case now. Potentially more complex situations cannot yet be planned.
> 
> Regards,
> 
> Pierre