Hi Jun-Hwan,

I'm mostly guessing here, but when you profile a field, it defaults to doing a mass-weighted profile, such that the value for any bin in the profile is:
Sum (field * mass) / Sum (mass).
If your object is a very flat disk, then there is probably not much mass outside the plane of the disk, so even when you do a spherical profile, the cells in the disk are dominating the average.  My guess is that if you switch to doing a volume-weighted profile of the density, you will get answers that differ more.  You can do that in the add_field call by adding weight_field="CellVolume".


On Tue, Jan 8, 2013 at 12:50 PM, Jun-Hwan Choi <jhchoi@pa.uky.edu> wrote:
Hi all,

I have a gas disk simulation and try to compute gas density profile.
I generate to make spherical average density profile by feeding a sphere object to the BinnedProfile1D and cylindrical average density profile by feeding a disk object to the BinnedProfile1D.
Surprisingly, both density profile is almost the same.
Does any one have idea why?
FYI, I past my yt script at  http://paste.yt-project.org/show/3046/ .

Thank you in advance.

Jun-Hwan Choi, Ph.D.
Department of Physics and Astronomy, University of Kentucky
Tel: (859) 897-6737        Fax: (859) 323-2846
Email: jhchoi@pa.uky.edu   URL: http://www.pa.uky.edu/~jhchoi

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