gala.dynamics.find_actions(orbit, N_max, force_harmonic_oscillator=False, toy_potential=None)[source]

Find approximate actions and angles for samples of a phase-space orbit. Uses toy potentials with known, analytic action-angle transformations to approximate the true coordinates as a Fourier sum.

This code is adapted from Jason Sanders’ genfunc


orbit : Orbit

N_max : int

Maximum integer Fourier mode vector length, \(|\boldsymbol{n}|\).

force_harmonic_oscillator : bool (optional)

Force using the harmonic oscillator potential as the toy potential.

toy_potential : Potential (optional)

Fix the toy potential class.


aaf : dict

A Python dictionary containing the actions, angles, frequencies, and value of the generating function and derivatives for each integer vector. Each value of the dictionary is a numpy.ndarray or astropy.units.Quantity.