# galpy.potential.Potential.__call__¶

Warning

galpy potentials do not necessarily approach zero at infinity. To compute, for example, the escape velocity or whether or not an orbit is unbound, you need to take into account the value of the potential at infinity. E.g., $$v_{\mathrm{esc}}(r) = \sqrt{2[\Phi(\infty)-\Phi(r)]}$$.

Potential.__call__(R, z, phi=0.0, t=0.0, dR=0, dphi=0)[source]

NAME:

__call__

PURPOSE:

evaluate the potential at (R,z,phi,t)

INPUT:

R - Cylindrical Galactocentric radius (can be Quantity)

z - vertical height (can be Quantity)

phi - azimuth (optional; can be Quantity)

t - time (optional; can be Quantity)

OUTPUT:

Phi(R,z,t)

HISTORY:

2010-04-16 - Written - Bovy (NYU)