galpy.potential.Potential.phiforce

Potential.phiforce(R, z, phi=0.0, t=0.0)

NAME:

phiforce

PURPOSE:

evaluate the azimuthal force F_phi = -d Phi / d phi (R,z,phi,t) [note that this is a torque, not a force!)

INPUT:

R - Cylindrical Galactocentric radius (can be Quantity)

z - vertical height (can be Quantity)

phi - azimuth (rad; can be Quantity)

t - time (optional; can be Quantity)

OUTPUT:

F_phi (R,z,phi,t)

HISTORY:

2010-07-10 - Written - Bovy (NYU)