galpy.potential.evaluaterforces(Pot, R, z, phi=None, t=0.0, v=None)[source]

Evaluate the radial force at a given position due to a potential, force or a list of potentials/forces.

  • Pot (Potential, DissipativeForce or list of Potential or DissipativeForce instances) – A potential, dissipative force or a list of such objects.

  • R (float or Quantity) – Cylindrical Galactocentric distance.

  • z (float or Quantity) – Distance above the plane.

  • phi (float or Quantity, optional) – Azimuth (default: None).

  • t (float or Quantity, optional) – Time (default: 0.0).

  • v (numpy.ndarray or Quantity, optional) – Current velocity in cylindrical coordinates. Required when including dissipative forces. Default is None.


The radial force F_r(R,z,phi,t).

Return type:

float or Quantity


  • 2016-06-10 - Written - Bovy (UofT)