Yeah, doing the full pairwise summation is pretty slow; the only instance of CUDA code in yt is actually a CUDA-fied version of this summation that I wrote for the Turk, Abel, O'Shea 2009 paper, because our clumps were composed of so many cells we had to speed up the binding energy calculation. If you were to write a tree solver, that would be great, but it might require a bit of effort on your part to get the cell parentage correct. One option would be to use the completely untested, completely unused Octree that I wrote, add all the cells to it, and then try to get the correct potential out of it. The problem there is that coarse cells that don't fully cover will need to have the non-included cells subtracted off. But maybe you can figure out a way around this?
On Thu, Mar 3, 2011 at 8:15 PM, Stephen Skory email@example.com wrote:
I've been working with the clump finder, and am becoming impatient with the gravitationally bound test calculation. I'm a very important person! Ok, sorry, I'm back to serious now. I'm wondering if we think that implementing some kind of tree code or pixelation of cells to lower resolution levels would be practical and accurate enough? It would make the double loop much smaller and quicker, and there could be a single user-controlled parameter that sets the desired accuracy. There are even parallel tree codes out there that we may be able to crib from.
Any thoughts would be appreciated!
Stephen Skory firstname.lastname@example.org http://stephenskory.com/ 510.621.3687 (google voice) _______________________________________________ Yt-dev mailing list Ytemail@example.com http://lists.spacepope.org/listinfo.cgi/yt-dev-spacepope.org