[yt-users] YT's treecode

[Andrew Davis]

Hello again,

First, thanks for the code fix.  I am, however having some problems with the
speed up -- at the moment, I'm not seeing any, unfortunately.

I'm testing this with ~ 140000 cells of a zoom in AMR simulation.  The number of
levels in the region is 11, so it's very similar to what is posted on the YT
clump-finding help page
(http://yt.enzotools.org/doc/analysis_modules/clump_finding.html#treecode-optimization)
-- namely the first figure for L=10 dataset with slightly fewer cells.

When I run:
> sp = pf.h.sphere(c,0.065/pf['pc'])
> pot = sp.quantities["IsBound"](truncate=False, include_thermal_energy=False,
treecode=False, opening_angle=0.0)

the timing is just ~230 seconds.

However, just changing to opening_angle=1.0 and treecode=True, the time is
roughly 900 seconds.
Higher opening angles only decrease the time by a little bit (opening_angle =
8.0 takes rougly 850 seconds).  The error is still very small, so it is
calculating the right number at least, just slower than I think it should, as
the figures on the help page suggest around a factor of two speedup is
expected.

Is there anything that you see that I'm doing wrong?

Thanks!

Andrew
*************************************************************
**  Andrew J. Davis             andrew.davis at yale.edu      **
**  Dept. of Astronomy          203-432-5119               **
**  Yale University             www.astro.yale.edu/adavis  **
*************************************************************