jmath.units package

Submodules

jmath.units.annotation module

Provides functions to allow for annotation of functions to enforce units.

jmath.units.annotation.annotate(func)

Converts the units of a function to those specified in function annotations.

Parameters

func (Callable) – The wrapped function to process.

Return type

Callable

Examples

>>> from jmath import Unit, units
>>> from jmath.units import si
>>> # Setup custom units
>>> gram = Unit("g")
>>> units.define_conversion(si.kilogram, gram, 1000)
>>> # Example function
>>> # Expects mass in kilograms, returns energy in joules as annotated
>>> @units.annotate
... def calc_energy(mass: si.kilogram) -> si.joules:
...     print(mass)
...     return mass/1e15
>>> input_mass = 3 * gram
>>> print(input_mass)
3 [g]
>>> energy = calc_energy(input_mass)
0.003 [kg]
>>> print(energy)
0.27 [J]

jmath.units.conversion module

Unit Spaces. For management of unit conversions and aliases.

class jmath.units.conversion.UnitSpace

Bases: object

Management for units and unit conversions.

alias(unit)

Produces the alias of a unit.

Parameters

unit (Unit) – The unit to find the alias of.

Return type

Optional[Unit]

convert(from_unit, to_unit)

Converts a unit to another unit if possible.

Parameters

  • from_unit (Unit) – The unit to convert from

  • to_unit (Unit) – The unit to convert to

Raises

NoConversion – Raises the no conversion error if there is no way to conver the unit.

Return type

Optional[Unit]

define_alias(base_unit, end_unit)

Defines an alias from unit to another.

Parameters

  • base_unit (Union[Unit, str]) – The unit to start at.

  • end_unit (Unit) – The unit to end at.

define_conversion(from_unit, to_unit, factor)

Defines the conversion between two units

Parameters

  • from_unit (Unit) – The unit to convert from.

  • to_unit (Unit) – The unit to convert to.

  • factor (Union[float, Unit, Callable[[float], float]]) – The factor to multiply by or a function to produce the difference. If a factor is passed then the reverse conversion is added by default. If a function is passed then the reverse conversion is not added by default.

jmath.units.conversion.define_alias(base_unit, end_unit)

Defines an alias from unit to another.

Parameters

  • base_unit (Union[Unit, str]) – The unit to start at.

  • end_unit (Unit) – The unit to end at.

jmath.units.conversion.define_conversion(from_unit, to_unit, factor)

Defines the conversion between two units

Parameters

  • from_unit (Unit) – The unit to convert from.

  • to_unit (Unit) – The unit to convert to.

  • factor (Union[float, Unit, Callable[[float], float]]) – The factor to multiply by or a function to produce the difference. If a factor is passed then the reverse conversion is added by default. If a function is passed then the reverse conversion is not added by default.

jmath.units.other module

Defines a set of other useful units.

jmath.units.si module

Defines a set of SI units and their conversion factors.

Examples

>>> from jmath.units import si
>>> voltage_drop = Uncertainty(3, 0.2) * si.volt
>>> current = Uncertainty(0.1, 0.02) * si.ampere
>>> resistance = voltage_drop/current
>>> print(resistance)
(30 ± 8) [Ω]

jmath.units.units module

Defines the unit class and its behaviour

class jmath.units.units.Unit(unit=None, unit_space=None)

Bases: object

A value with an associated unit.

Parameters

Examples

>>> print(3 * Unit("m")/Unit("s"))
3 [ms^(-1)]
convert_to(other)

Converts the current unit to the given unit.

Parameters

other (jmath.units.units.Unit) – The type of unit to convert to.

copy(value=None, flip_powers=False)

Produces a copy of the unit.

Parameters

  • value (Optional[float]) – Optional overwrite of value.

  • flip_powers – Optional flipping of powers.

Return type

jmath.units.units.Unit

union(other)

Constructs the union of two units. Ignores values.

Parameters

other (jmath.units.units.Unit) – The other set to construct the union with.

Return type

jmath.units.units.Unit

property unit_space

The Unitspace in which the Unit Exists.

unit_str()

Produces a string describing the unit.

Return type

str

Module contents

Maths with Units