Starlab version 4.4.1
    program created on Apr 27 2005 at 22:52:25
    source file     /home/steve/starlab/src/node/dyn/util/compute_mean_cod.C

Determine the density center position and velocity for the input N-body
system.  The density center is defined analogously to the center of mass,
but instead of a mass weighting, the weighting used is proportional to
the square of the density (the original suggestion in the paper below(*),
to use a weighting factor linear in the density, may not converge well).
Densities are not computed here -- run compute_density before invoking
compute_mean_cod.  Density center position and velocity are written to
the dyn story of the top-level node; they are also optionally returned as
function arguments in the library version.

(*) Stefano Casertano and Piet Hut: Astroph.J. 298,80 (1985).
To use their recipe, k >= 2 is required.

Note: The computed density center is defined in absolute terms, and so
includes the pos and vel of the parent node.

Usage: compute_mean_cod [OPTIONS] < input > output

Options:     
		  -c    add a comment to the output snapshot [false]

Written by Piet Hut, Steve McMilland, and Jun Makino.

Report bugs to starlab (at) sns.ias.edu.