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Python

r"""
==================================
Constants (:mod:`scipy.constants`)
==================================
.. currentmodule:: scipy.constants
Physical and mathematical constants and units.
Mathematical constants
======================
================ =================================================================
``pi`` Pi
``golden`` Golden ratio
``golden_ratio`` Golden ratio
================ =================================================================
Physical constants
==================
=========================== =================================================================
``c`` speed of light in vacuum
``speed_of_light`` speed of light in vacuum
``mu_0`` the magnetic constant :math:`\mu_0`
``epsilon_0`` the electric constant (vacuum permittivity), :math:`\epsilon_0`
``h`` the Planck constant :math:`h`
``Planck`` the Planck constant :math:`h`
``hbar`` :math:`\hbar = h/(2\pi)`
``G`` Newtonian constant of gravitation
``gravitational_constant`` Newtonian constant of gravitation
``g`` standard acceleration of gravity
``e`` elementary charge
``elementary_charge`` elementary charge
``R`` molar gas constant
``gas_constant`` molar gas constant
``alpha`` fine-structure constant
``fine_structure`` fine-structure constant
``N_A`` Avogadro constant
``Avogadro`` Avogadro constant
``k`` Boltzmann constant
``Boltzmann`` Boltzmann constant
``sigma`` Stefan-Boltzmann constant :math:`\sigma`
``Stefan_Boltzmann`` Stefan-Boltzmann constant :math:`\sigma`
``Wien`` Wien displacement law constant
``Rydberg`` Rydberg constant
``m_e`` electron mass
``electron_mass`` electron mass
``m_p`` proton mass
``proton_mass`` proton mass
``m_n`` neutron mass
``neutron_mass`` neutron mass
=========================== =================================================================
Constants database
------------------
In addition to the above variables, :mod:`scipy.constants` also contains the
2014 CODATA recommended values [CODATA2014]_ database containing more physical
constants.
.. autosummary::
:toctree: generated/
value -- Value in physical_constants indexed by key
unit -- Unit in physical_constants indexed by key
precision -- Relative precision in physical_constants indexed by key
find -- Return list of physical_constant keys with a given string
ConstantWarning -- Constant sought not in newest CODATA data set
.. data:: physical_constants
Dictionary of physical constants, of the format
``physical_constants[name] = (value, unit, uncertainty)``.
Available constants:
====================================================================== ====
%(constant_names)s
====================================================================== ====
Units
=====
SI prefixes
-----------
============ =================================================================
``yotta`` :math:`10^{24}`
``zetta`` :math:`10^{21}`
``exa`` :math:`10^{18}`
``peta`` :math:`10^{15}`
``tera`` :math:`10^{12}`
``giga`` :math:`10^{9}`
``mega`` :math:`10^{6}`
``kilo`` :math:`10^{3}`
``hecto`` :math:`10^{2}`
``deka`` :math:`10^{1}`
``deci`` :math:`10^{-1}`
``centi`` :math:`10^{-2}`
``milli`` :math:`10^{-3}`
``micro`` :math:`10^{-6}`
``nano`` :math:`10^{-9}`
``pico`` :math:`10^{-12}`
``femto`` :math:`10^{-15}`
``atto`` :math:`10^{-18}`
``zepto`` :math:`10^{-21}`
============ =================================================================
Binary prefixes
---------------
============ =================================================================
``kibi`` :math:`2^{10}`
``mebi`` :math:`2^{20}`
``gibi`` :math:`2^{30}`
``tebi`` :math:`2^{40}`
``pebi`` :math:`2^{50}`
``exbi`` :math:`2^{60}`
``zebi`` :math:`2^{70}`
``yobi`` :math:`2^{80}`
============ =================================================================
Mass
----
================= ============================================================
``gram`` :math:`10^{-3}` kg
``metric_ton`` :math:`10^{3}` kg
``grain`` one grain in kg
``lb`` one pound (avoirdupous) in kg
``pound`` one pound (avoirdupous) in kg
``blob`` one inch version of a slug in kg (added in 1.0.0)
``slinch`` one inch version of a slug in kg (added in 1.0.0)
``slug`` one slug in kg (added in 1.0.0)
``oz`` one ounce in kg
``ounce`` one ounce in kg
``stone`` one stone in kg
``grain`` one grain in kg
``long_ton`` one long ton in kg
``short_ton`` one short ton in kg
``troy_ounce`` one Troy ounce in kg
``troy_pound`` one Troy pound in kg
``carat`` one carat in kg
``m_u`` atomic mass constant (in kg)
``u`` atomic mass constant (in kg)
``atomic_mass`` atomic mass constant (in kg)
================= ============================================================
Angle
-----
================= ============================================================
``degree`` degree in radians
``arcmin`` arc minute in radians
``arcminute`` arc minute in radians
``arcsec`` arc second in radians
``arcsecond`` arc second in radians
================= ============================================================
Time
----
================= ============================================================
``minute`` one minute in seconds
``hour`` one hour in seconds
``day`` one day in seconds
``week`` one week in seconds
``year`` one year (365 days) in seconds
``Julian_year`` one Julian year (365.25 days) in seconds
================= ============================================================
Length
------
===================== ============================================================
``inch`` one inch in meters
``foot`` one foot in meters
``yard`` one yard in meters
``mile`` one mile in meters
``mil`` one mil in meters
``pt`` one point in meters
``point`` one point in meters
``survey_foot`` one survey foot in meters
``survey_mile`` one survey mile in meters
``nautical_mile`` one nautical mile in meters
``fermi`` one Fermi in meters
``angstrom`` one Angstrom in meters
``micron`` one micron in meters
``au`` one astronomical unit in meters
``astronomical_unit`` one astronomical unit in meters
``light_year`` one light year in meters
``parsec`` one parsec in meters
===================== ============================================================
Pressure
--------
================= ============================================================
``atm`` standard atmosphere in pascals
``atmosphere`` standard atmosphere in pascals
``bar`` one bar in pascals
``torr`` one torr (mmHg) in pascals
``mmHg`` one torr (mmHg) in pascals
``psi`` one psi in pascals
================= ============================================================
Area
----
================= ============================================================
``hectare`` one hectare in square meters
``acre`` one acre in square meters
================= ============================================================
Volume
------
=================== ========================================================
``liter`` one liter in cubic meters
``litre`` one liter in cubic meters
``gallon`` one gallon (US) in cubic meters
``gallon_US`` one gallon (US) in cubic meters
``gallon_imp`` one gallon (UK) in cubic meters
``fluid_ounce`` one fluid ounce (US) in cubic meters
``fluid_ounce_US`` one fluid ounce (US) in cubic meters
``fluid_ounce_imp`` one fluid ounce (UK) in cubic meters
``bbl`` one barrel in cubic meters
``barrel`` one barrel in cubic meters
=================== ========================================================
Speed
-----
================== ==========================================================
``kmh`` kilometers per hour in meters per second
``mph`` miles per hour in meters per second
``mach`` one Mach (approx., at 15 C, 1 atm) in meters per second
``speed_of_sound`` one Mach (approx., at 15 C, 1 atm) in meters per second
``knot`` one knot in meters per second
================== ==========================================================
Temperature
-----------
===================== =======================================================
``zero_Celsius`` zero of Celsius scale in Kelvin
``degree_Fahrenheit`` one Fahrenheit (only differences) in Kelvins
===================== =======================================================
.. autosummary::
:toctree: generated/
convert_temperature
Energy
------
==================== =======================================================
``eV`` one electron volt in Joules
``electron_volt`` one electron volt in Joules
``calorie`` one calorie (thermochemical) in Joules
``calorie_th`` one calorie (thermochemical) in Joules
``calorie_IT`` one calorie (International Steam Table calorie, 1956) in Joules
``erg`` one erg in Joules
``Btu`` one British thermal unit (International Steam Table) in Joules
``Btu_IT`` one British thermal unit (International Steam Table) in Joules
``Btu_th`` one British thermal unit (thermochemical) in Joules
``ton_TNT`` one ton of TNT in Joules
==================== =======================================================
Power
-----
==================== =======================================================
``hp`` one horsepower in watts
``horsepower`` one horsepower in watts
==================== =======================================================
Force
-----
==================== =======================================================
``dyn`` one dyne in newtons
``dyne`` one dyne in newtons
``lbf`` one pound force in newtons
``pound_force`` one pound force in newtons
``kgf`` one kilogram force in newtons
``kilogram_force`` one kilogram force in newtons
==================== =======================================================
Optics
------
.. autosummary::
:toctree: generated/
lambda2nu
nu2lambda
References
==========
.. [CODATA2014] CODATA Recommended Values of the Fundamental
Physical Constants 2014.
https://physics.nist.gov/cuu/Constants/
"""
from __future__ import division, print_function, absolute_import
# Modules contributed by BasSw (wegwerp@gmail.com)
from .codata import *
from .constants import *
from .codata import _obsolete_constants
_constant_names = [(_k.lower(), _k, _v)
for _k, _v in physical_constants.items()
if _k not in _obsolete_constants]
_constant_names = "\n".join(["``%s``%s %s %s" % (_x[1], " "*(66-len(_x[1])),
_x[2][0], _x[2][1])
for _x in sorted(_constant_names)])
if __doc__ is not None:
__doc__ = __doc__ % dict(constant_names=_constant_names)
del _constant_names
__all__ = [s for s in dir() if not s.startswith('_')]
from scipy._lib._testutils import PytestTester
test = PytestTester(__name__)
del PytestTester