Core Unit Class

The Unit class is the foundation for all physical units in Quantium. Each Unit object stores its name (symbol), its conversion factor to the equivalent base SI unit, and its physical dimension.

class quantium.core.quantity.Unit(name: str, scale_to_si: float, dim: Dim)

Represents a physical unit. This class is generally not instantiated directly by users. Instead, users access predefined units from the default registry (see below) or create new units using the registry’s helper methods.

Parameters:

• name – The symbol or name of the unit (e.g., “m”, “kg”, “cm”).

• scale_to_si – The multiplicative factor to convert 1 of this unit to its SI equivalent.

• dim – The Dim object representing the unit’s physical dimension (L, M, T, I, Θ, N, J).

Attributes

name: str

Symbol or name (e.g., “m”, “s”, “kg”, “cm”).

scale_to_si: float

Multiplicative factor to convert 1 of this unit to SI for its dimension (e.g., m=1.0, cm=0.01, ft=0.3048).

dim: quantium.core.dimensions.Dim

Dimension vector (L,M,T,I,Θ,N,J).

Unit Arithmetic

Unit objects can be combined using arithmetic operators to create new, derived units.

__mul__(other: Unit) → Unit

Multiplies two units. (e.g., m * m returns Unit(name='m^2', ...))

__truediv__(other: Unit) → Unit

Divides two units. (e.g., m / s returns Unit(name='m/s', ...))

__rtruediv__(n: int | float) → Unit

Calculates the reciprocal of a unit. Only 1 / unit is supported (e.g., 1 / s returns Unit(name='s^-1', ...)).

__pow__(n: int) → Unit

Raises a unit to an integer power (e.g., m ** 2 returns Unit(name='m^2', ...)).

__rmul__(value: float) → Quantity

Creates a Quantity by multiplying a number with a unit. This is the magic that enables the 100 * u.m syntax.