Perform operations on SI units
Project description
SI Units
This is a library used to symbolically manipulate SI units. It comprises a BaseUnit
type,
used for base SI units like kilogram
, meter
etc, a DerivedUnit
type,
for units derived from them, and a Composite
type, for when numerical coefficients
are included.
This library is useful for dimensional analysis. Python version 3.7 or greater is required. There are no dependencies.
You can perform normal multiplication, division, and power operations on units
provided by this lib, and between them and int
s and floats
, and check equality,
based on the resulting combination of base units.
Examples
A base unit:
import siunits as u
u.kg
>>> kilogram (kg), mass
A derived unit:
u.v
>>> volt (V), [kg: 1, m: 2, s: -3, A: -1]
Multiplication:
u.kg * u.s
>>> kilogram·second (kg·s), [kg: 1, s: 1]
Division:
u.j / u.m**2
>>> joule / meter² (kg·s⁻²), [kg: 1, s: -2]
u.s**2 / u.kg**3
>>> second²·kilogram⁻³ (s²·kg⁻³), [s: 2, kg: -3]
With numerical coefficients:
2*u.a**2 * 3*u.v**2
>>> 6kg²·m⁴·s⁻⁶
Equality testing is based on composition of base units:
u.w == u.v * u.a == u.kg * u.m**2 / u.s**3
>>> True
Todo
- Infer composite types that match a given custom (eg multiplied) unit
- Apply arithmetic to quantities as well (eg
energy
,work
etc), and display them
Scope
This project doesn't aim to provide conversions with other unit systems, like
cgs
and imperial
, nor does it provide physical constants. For these
tasks, try scipy.constants.
Why add another unit library?
The clean symbolic manipulation this library provides doesn't appear to exist in any existing one.
Project details
Download files
Download the file for your platform. If you're not sure which to choose, learn more about installing packages.