🌌 Gala

The gala package provides tools for Galactic dynamics. It is built on top of the astropy package and adds an additional units tool, the gala.units.UnitSystem class that can be used to convert between different unit systems.

unxt supports gala unit systems as inputs, converting them to unxt.unitsystems.AbstractUnitSystem objects. This conversion is automatically enabled if gala is installed. unxt is compatible with most versions of gala, but to ensure that compatible versions of gala and unxt are installed, the following installation extra is provided:

uv

uv add "unxt[interop-gala]"

pip

pip install "unxt[interop-gala]"

The following example demonstrates how to convert a gala unit system to a unxt unit system:

>>> import unxt
>>> import gala.units as gu

>>> gu.galactic  # gala unit system
<UnitSystem (kpc, Myr, solMass, rad)>

>>> unxt.unitsystem(gu.galactic)  # unxt unit system
unitsystem(kpc, Myr, solMass, rad)

Alternatively, the multiple-dispatch library on which unxt is built enables 2-way conversion.

>>> from plum import convert

>>> usys = convert(gu.galactic, unxt.AbstractUnitSystem)
>>> usys
unitsystem(kpc, Myr, solMass, rad)

>>> convert(usys, gu.UnitSystem)
<UnitSystem (kpc, Myr, solMass, rad)>