gspdisk                           Make exponential disk in a gsp model

  grav=                           Input gsp file sets spheroid gravity.
				  If blank, just use disk self-gravity.

  out=                            Output N-body file with disk model.
				  Contains Mass, Position, Velocity data.

  mdisk=0.1875                    Exponential disk mass (or masses).
				  Can take two comma-separated values;
				  uses 1st for N-body model, adds 2nd to
				  grav. field.  If so, must also specify
				  two values for alpha and epsilon.

  alpha=12.0                      Inverse radial scale length(s)

  epsilon=-1                      Plummer smoothing parameter(s).
				  No smoothing is used if epsilon < 0.

  zdisk=0.01                      Vertical scale height; sets dispersions

  mu=2.0                          Ratio of radial to vertical dispersion.
				  Constant unless r_mu > 0.

  r_mu=-1                         Scale radius for mu(R) function.
				  If r_mu > 0 then mu -> 1 as R -> 0.

  eta=-1                          Velocity distribution parameter.
				  Use Gaussian distribution if eta < 0.

  rcut=1.0                        Outer disk cutoff radius

  nlist=256                       Number of radii in disk listing

  ndisk=12288                     Number of disk particles

  seed=54321                      Seed for random number generator

  VERSION=1.4                     Josh Barnes  12 May 2012

Joshua E. Barnes      (barnes at
Created: 14 June 2012
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