galpy.potential.evaluater2derivs(Pot, R, z, phi=None, t=0.0)[source]

Evaluate the second (spherical) radial derivative of a potential or sum of potentials.

  • Pot (Potential or list of Potential instances) – A potential or list of potentials (dissipative forces in such a list are ignored).

  • 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).


The second (spherical) radial derivative d2Phi/d2r of the potential.

Return type:

float or Quantity


  • 2018-03-28 - Written - Bovy (UofT)