galpy.potential.Potential.R2deriv¶
- Potential.R2deriv(R, z, phi=0.0, t=0.0)[source]¶
NAME:
R2deriv
PURPOSE:
evaluate the second radial derivative
INPUT:
R - Galactocentric radius (can be Quantity)
z - vertical height (can be Quantity)
phi - Galactocentric azimuth (can be Quantity)
t - time (can be Quantity)
OUTPUT:
d2phi/dR2
HISTORY:
2011-10-09 - Written - Bovy (IAS)