CompositeUnit¶

class astropy.units.CompositeUnit(scale, bases, powers, decompose=False, decompose_bases={}, _error_check=True)[source]¶

Create a composite unit using expressions of previously defined units.

Direct use of this class is not recommended. Instead use the factory function Unit and arithmetic operators to compose units.

Parameters

scalenumber: A scaling factor for the unit.
basessequence of UnitBase: A sequence of units this unit is composed of.
powerssequence of numbers: A sequence of powers (in parallel with bases) for each of the base units.

Attributes Summary

`bases`	Return the bases of the composite unit.
`powers`	Return the powers of the composite unit.
`scale`	Return the scale of the composite unit.

Methods Summary

`decompose`([bases])	Return a unit object composed of only irreducible units.
`is_unity`()	Returns `True` if the unit is unscaled and dimensionless.

Attributes Documentation

Methods Documentation

decompose(bases={})[source]¶

Return a unit object composed of only irreducible units.

Parameters

basessequence of UnitBase, optional: The bases to decompose into. When not provided, decomposes down to any irreducible units. When provided, the decomposed result will only contain the given units. This will raises a UnitsError if it’s not possible to do so.

Returns

unitCompositeUnit object: New object containing only irreducible unit objects.

is_unity()[source]¶: Returns True if the unit is unscaled and dimensionless.