vice.toolkit.hydrodisk.hydrodiskstars.mode
==========================================

Type : str [case-insensitive] or ``None``

Default : "diffusion"

Recognized Values
-----------------
The following is a breakdown of how stellar populations migrate in
multizone simulations under each approximation.

- "diffusion"
	The orbital radius at times between birth and 13.2 Gyr are assigned
	via a sqrt(time) dependence, the mean displacement if stars
	migrated according to a random walk. Stellar populations spiral
	inward or outward with a smooth time dependence in this model.
- "linear"
	Orbital radii at times between birth and 13.2 Gyr are assigned via
	linear interpolation. Stellar populations therefore spiral
	uniformly inward or outward from birth to final radii, with orbital
	radius changing more slowly for young stars than in the diffusion
	model, but more quickly for old stars.
- "sudden"
	The time of migration is randomly drawn from a uniform distribution
	between when a stellar population is born and 13.2 Gyr. At times
	prior to this, it is at its radius of birth; at subsequent times,
	it is at its final radius. Stellar populations therefore spend no
	time at intermediate radii.
- ``None``
	Only supported for subclasses of the hydrodiskstars object, this
	should be used when the user intends to override the built-in
	migration assumptions and implement a different one. In these
	cases, the ``__call__`` method should be overridden in addition to
	this attribute being set to ``None``.

.. note:: The "post-processing" model from Johnson et al. (2021) [1]_
	corresponds to setting the attribute ``simple = True`` in the
	``milkyway`` object, inherited from the base class ``multizone``.

Example Code
------------
>>> from vice.toolkit.hydrodisk import hydrodiskstars
>>> import numpy as np
>>> example = hydrodiskstars(np.linspace(0, 20, 81))
>>> example.mode
'diffusion'
>>> example.mode = "sudden"
>>> example.mode = "linear"

.. [1] Johnson et al. (2021), 2103.09838