Constants

Scala breeze constant values are taken from The NIST Reference on Constants, Units and Uncertainty (2010), and are in SI units. Selected constants are available directly, the other NIST constants are available via database search.

##Accessing CODATA2010 constants

import breeze.numerics.constants._

Regex versions of the function will return a Vector of a Tuple2 of the matched value names and value. (i.e. val values: Vector[(String, Double)] = Database.value(regex))

	Breeze	Scipy
a list of values	Database.list()	``
specific value	Database.value(string: String)	value(key)
(value by regex)	Database.value(regex: Regex) i.e. Database.value("""regex string""".r)
uncertainty	Database.uncertainty(string: String)	precision(key)
(uncertainty by regex)	Database.uncertainty (regex: Regex)
unit	Database.unit (string: String)	unit (key)
(unit by regex)	Database.unit (regex: Regex)

##Accessing selected constants directly import breeze.numerics.constants._

Mathematical

Constant	Breeze	Scipy
	breeze.numerics.constants._	scipy.constants._
Pi	Pi	pi
golden ratio	GoldenRatio	golden

Electromagnetic

Constant	Breeze	Scipy
	breeze.numerics.constants._	scipy.constants._
magnetic constant	MagneticConstant or Mu0	mu_0
electric constant (vacuum permittivity)	ElectricConstant or Epsilon0	epsilon_0
fine structure constant	FineStructureConstant or Alpha	alpha

Mechanics

Constant	Breeze	Scipy
	breeze.numerics.constants._	scipy.constants._
gravitation constant	GravitationConstant	G
standard acceleration of gravity	StandardAccelerationOfGravity or g	g

Thermodynamics

Constant	Breeze	Scipy
	breeze.numerics.constants._	scipy.constants._
Avogadro number	AvogadroNumber or NA	N_A
molar gas constant	MolarGasConstant or R	R
Boltzmann constant	BoltzmannConstant or k	k

Particle

Constant	Breeze	Scipy
	breeze.numerics.constants._	scipy.constants._
light speed	LightSpeed or c	c
Planck constant	PlanckConstant or h	h
h bar === h/(2 Pi)	hBar	hbar
elementary charge	ElementaryCharge or e	e
electron mass	ElectronMass	m_e
proton mass	ProtonMass	m_p
neutron mass	NeutronMass	m_n
Rydberg constant	RydbergConstant	Rydberg
Wien displacement law constant	WienDisplacementLawConstant or Wien	Wien
Stefan-Boltzmann constant	StefanBoltzmannConstant or sigma	sigma

SI Prefixes

Constant (Breeze/Scipy)	value
yotta	1E24
zetta	1E21
exa	1E18
peta	1E15
tera	1E12
giga	1E9
mega	1E6
kilo	1E3
hecto	1E2
deca (deka in Scipy)	1E1
deci	1E-1
centi	1E-2
milli	1E-3
micro	1E-6
nano	1E-9
pico	1E-12
femto	1E-15
atto	1E-18
zepto	1E-21
yocto (not present in Scipy)	1E-24

ICE Binary Prefixes

Constant (Breeze/Scipy)	value
kibi	2^10
mebi	2^20
gibi	2^30
tebi	2^40
pebi	2^50
exbi	2^60
zebi	2^70
yobi	2^80