[yt-users] Best way to create radial bins

[Thomas Hansen]

Hi everyone,

I'm kind of new to yt and am currently working on creating a set of graphs
but am having a bit of difficulty.  My goal is to take a list of central
points (a set of x,y,z coordinates) and then look at a set of 30 spherical
"shells" which surround the central points.  So I want to be able to know
how much mass is between, say 30 and 60 parsecs away from a certain point
(along with 60-90, 90-120, etc.).  The problem is, the number of points is
absolutely massive, so I need a fairly quick way of finding these values
for all the points I'm interested in.

I've tried a few tactics already.  First I tried going to each point,
creating a sphere with that center and the maximum radius.  Then I used the
center location to set a field parameter, then created a BinnedProfile1D
using a "radius" field and the sphere I created, but that seemed to be
impractically slow.

Next, I tried the somewhat hackish method of for each point, creating a
series of 30 spheres with radii corresponding with the boundaries I wanted
between the shells.  I then used the boolean("NOT") command to construct a
series of shells by finding the part of each sphere not in the smaller
one.  I could then sum over the values in each shell.  This seemed to go a
bit faster, but I feel like this could use an absolutely massive amount of
computation, if I understand how yt works properly.

Is there a better way of doing this?

Thank you so much for your time,
Thomas
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