Class that implements spherical potentials that are derived from two-power density models
NAME:
__init__
PURPOSE:
initialize a two-power-density potential
INPUT:
amp - amplitude to be applied to the potential (default: 1)
a - “scale” (in terms of Ro)
alpha - inner power
beta - outer power
normalize - if True, normalize such that vc(1.,0.)=1., or, if given as a number, such that the force is this fraction of the force necessary to make vc(1.,0.)=1.
OUTPUT:
(none)
HISTORY:
2010-07-09 - Started - Bovy (NYU)