Anybody have any thoughts on this? I'd like to wrap this up in the next four days, if possible. On Fri, Feb 20, 2009 at 5:49 PM, Matthew Turk <matthewturk@gmail.com> wrote:
Hi Stephen and others,
After my first email, I realized that we should not want the Domain to be considered equal, but that I think we should not consider the dx's to be different. This breaks a bit of generalization, but I'm okay with that. Domains I think we should keep general. I propose that we accept a parameter:
minimum_halo_mass
which we can use to come up with padding by:
rho = total_mass / product(root_grid_dimensions)
this gives us a mass per root grid cell. (Note that this is also the mean dark matter density of the universe, if we only have DM particles. But HOP is more general than just DM, so we do not make this assumption.) We should have padding such that it's over-resolving our minimum mass by some factor B.
padding = B * root_dx * minimum_halo_mass / rho
The reason I'm looking at this in terms of root grid cells is the typical sync between root grid cells and the particles; Brian's done some work with particle dimensions differing from the hydro dims, but I think what we can consider is that even in that case, the two are *correlated* by some multiple of RefineBy. The same is true for simulations with "zoom" particles.
Maybe I'm on the wrong track, but does this make sense to anyone else? Brian, Britton?
-Matt
On Fri, Feb 20, 2009 at 3:18 PM, Stephen Skory <stephenskory@yahoo.com> wrote:
I personally feel we should allow the user to specify the minimum percentage of the matter enclosed in their box, and provide a relatively low value for this. From this, a length scale drops out, based on the total number of particles and the domain size. We cannot assume that the domain runs from 0 to 1 or that the three axes are identical.
That's an OK solution for the dimensional problems you raise.
_______________________________________________________ sskory@physics.ucsd.edu o__ Stephen Skory http://physics.ucsd.edu/~sskory/ _.>/ _Graduate Student ________________________________(_)_\(_)_______________ _______________________________________________ Yt-dev mailing list Yt-dev@lists.spacepope.org http://lists.spacepope.org/listinfo.cgi/yt-dev-spacepope.org