Orbit

class gala.dynamics.Orbit

Bases: object

Attributes Summary

norbits
ntimes

Methods Summary

apocenter([type])	Estimate the apocenter(s) of the orbit.
eccentricity()	Returns the eccentricity computed from the mean apocenter and mean pericenter.
estimate_period([radial])	Estimate the period of the orbit.
pericenter([type])	Estimate the pericenter(s) of the orbit.

Attributes Documentation

norbits

ntimes

Methods Documentation

apocenter(type=<function mean>)

Estimate the apocenter(s) of the orbit. By default, this returns the mean apocenter. To get, e.g., the minimum apocenter, pass in type=np.min. To get all apocenters, pass in type=None.

Parameters:

type : func (optional)

By default, this returns the mean apocenter. To return all apocenters, pass in None. To get, e.g., the minimum or maximum apocenter, pass in np.min or np.max.

Returns:

apo : float, ndarray

Either a single number or an array of apocenters.

eccentricity()

Returns the eccentricity computed from the mean apocenter and mean pericenter.

\[e = \frac{r_{\rm apo} - r_{\rm per}}{r_{\rm apo} + r_{\rm per}}\]

Returns:

ecc : float

The orbital eccentricity.

estimate_period(radial=True)

Estimate the period of the orbit. By default, computes the radial period. If radial==False, this returns period estimates for each dimension of the orbit.

Parameters:

radial : bool (optional)

What period to estimate. If True, estimates the radial period. If False, estimates period in each dimension, e.g., if the orbit is 3D, along x, y, and z.

Returns:

T : Quantity

The period or periods.

pericenter(type=<function mean>)

Estimate the pericenter(s) of the orbit. By default, this returns the mean pericenter. To get, e.g., the minimum pericenter, pass in type=np.min. To get all pericenters, pass in type=None.

Parameters:

type : func (optional)

By default, this returns the mean pericenter. To return all pericenters, pass in None. To get, e.g., the minimum or maximum pericenter, pass in np.min or np.max.

Returns:

peri : float, ndarray

Either a single number or an array of pericenters.