galpy.potential.evaluatephizderivs

galpy.potential.evaluatephizderivs(Pot, R, z, phi=None, t=0.0)

Evaluate the second derivative of the sum of potentials with respect to cylindrical azimuth and height.

Parameters:

• 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).

Returns:

The second derivative d2Phi/dphidz of the sum of potentials with respect to cylindrical azimuth and height.

Return type:

float or Quantity

Notes

• 2021-04-30 - Written - Bovy (UofT)