units

Unit definitions and surrounding Value system.

A quick note on what this module does not do: it does not set out a complete unit system, and you will experience issues if you use it that way.

This system is designed purely for the ergonomic specification of units of a quantity at display time, and because of this, it is designed to precisely mirror the form of the expression as it is written in code. The below highlights a particular quirk of this.

>>> 1 / (KILO * VOLT) == 1 * KILO / VOLT
True

This is because the system stores units as they would be written, and you would write \(\mathrm{1 / kV = 1 kV^{-1}}\) and not \(\mathrm{1 k^{-1} V^{-1}}\).

Available prefixes

Prefix variable	Displayed as
QUETTA	Q
RONNA	R
YOTTA	Y
ZETTA	Z
EXA	E
PETA	P
TERA	T
GIGA	G
MEGA	M
KILO	k
HECTO	h
DECA	da
DECI	d
CENTI	c
MILLI	m
MICRO	µ
NANO	n
PICO	p
FEMTO	f
ATTO	a
ZEPTO	z
YOCTO	y
RONTO	r
QUECTO	q
YOBI	Yi
ZEBI	Zi
EXBI	Ei
PEBI	Pi
TEBI	Ti
GIBI	Gi
MEBI	Mi
KIBI	Ki

Available units

Length/area/volume

Unit variable	Displayed as
METRE	m
METER
ANGSTROM	Å
MICRON	μm
LITRE	L
LITER

Mass

Unit variable	Displayed as
GRAM	g

Time/frequency

Unit variable	Displayed as
SECOND	s
MINUTE	min
HOUR	hr
HERTZ	Hz

Electricity

Unit variable	Displayed as
AMP	A
VOLT	V
OHM	Ω
SIEMENS	S
FARAD	F
HENRY	H
COULOMB	C

Temperature

Unit variable	Displayed as
KELVIN	K
CELSIUS	°C

Illumination

Unit variable	Displayed as
CANDELA	cd
LUMEN	lm
LUX	lx

Quantity

Unit variable	Displayed as
MOLE	mol

Angles

Unit variable	Displayed as
DEGREE	°
RADIAN	rad
STERADIAN	sr

Energy and power

Unit variable	Displayed as
JOULE	J
ELECTRONVOLT	eV
WATT	W
DECIBEL	dB

Force and pressure

Unit variable	Displayed as
NEWTON	N
PASCAL	Pa
BAR	bar

Magnetism

Unit variable	Displayed as
WEBER	Wb
TESLA	T

Digital storage

Unit variable	Displayed as
BIT	b
BYTE	B

Classes

E	Unit representing scientific notation.
Unit	An SI unit or prefix.
UnitSequence	A sequence of individual units.
Value	Representation of a quantity with units for display purposes.