isochrone_to_aa¶
- gala.dynamics.isochrone_to_aa(w, potential)[source]¶
Transform the input cartesian position and velocity to action-angle coordinates in the Isochrone potential. See Section 3.5.2 in Binney & Tremaine (2008), and be aware of the errata entry for Eq. 3.225.
This transformation is analytic and can be used as a “toy potential” in the Sanders & Binney (2014) formalism for computing action-angle coordinates in any potential.
Note
This function is included as a method of the
IsochronePotential
and it is recommended to callphase_space()
instead.- Parameters
- w
gala.dynamics.PhaseSpacePosition
,gala.dynamics.Orbit
- potential
gala.potential.IsochronePotential
,dict
An instance of the potential to use for computing the transformation to angle-action coordinates. Or, a dictionary of parameters used to define an
gala.potential.IsochronePotential
instance.
- w
- Returns
- actions
numpy.ndarray
An array of actions computed from the input positions and velocities.
- angles
numpy.ndarray
An array of angles computed from the input positions and velocities.
- freqs
numpy.ndarray
An array of frequencies computed from the input positions and velocities.
- actions