Various units-related things

This module has a soft dependency on the pint units library. Please import this module only conditionally or only if you can accept a pint dependency.

FwmuMixin Mixing for frequency/wavelength/wavenumber neutrality
SRF(f, W) Respresents a spectral response function
density(p, T[, R]) Wrapper around typhon.physics.thermodynamics.density().
planck_f(f, T) Planck law expressed in frequency.
radiance_units dict() -> new empty dictionary dict(mapping) -> new dictionary initialized from a mapping object’s (key, value) pairs dict(iterable) -> new dictionary initialized as if via: d = {} for k, v in iterable: d[k] = v dict(**kwargs) -> new dictionary initialized with the name=value pairs in the keyword argument list.For example: dict(one=1, two=2).
specrad_frequency_to_planck_bt(L, f) Convert spectral radiance per frequency to brightness temperature
specrad_wavenumber2frequency(specrad_wavenum) Convert spectral radiance from per wavenumber to per frequency
ureg The unit registry stores the definitions and relationships between units.


Collection of physical constants and conversion factors.

The magnitudes of the defined constants are taken from typhon.constants.

This module adds units defined with pint’s UnitRegistry..

Physical constants

g Earth standard gravity
h Planck constant
k Boltzmann constant
c Speed of light
N_A Avogadro constant
R Universal gas constant
molar_mass_dry_air Molar mass for dry air
molar_mass_water Molar mass for water vapor
gas_constant_dry_air Gas constant for dry air
gas_constant_water_vapor Gas constant for water vapor

Mathematical constants

golden Golden ratio

SI prefixes

yotta \(10^{24}\)
zetta \(10^{21}\)
exa \(10^{18}\)
peta \(10^{15}\)
tera \(10^{12}\)
giga \(10^{9}\)
mega \(10^{6}\)
kilo \(10^{3}\)
hecto \(10^{2}\)
deka \(10^{1}\)
deci \(10^{-1}\)
centi \(10^{-2}\)
milli \(10^{-3}\)
micro \(10^{-6}\)
nano \(10^{-9}\)
pico \(10^{-12}\)
femto \(10^{-15}\)
atto \(10^{-18}\)
zepto \(10^{-21}\)

Non-SI ratios

ppm \(10^{-6}\) parts per million
ppb \(10^{-9}\) parts per billion
ppt \(10^{-12}\) parts per trillion

Binary prefixes

kibi, KiB \(2^{10}\)
mebi, MiB \(2^{20}\)
gibi \(2^{30}\)
tebi \(2^{40}\)
pebi \(2^{50}\)
exbi \(2^{60}\)
zebi \(2^{70}\)
yobi \(2^{80}\)
KB \(10^3\)
MB \(10^6\)

Earth characteristics

earth_mass Earth mass
earth_radius Earth radius
atm Standard atmosphere