""" ================================== Constants (:mod:`scipy.constants`) ================================== .. currentmodule:: scipy.constants Physical and mathematical constants and units. Mathematical constants ====================== ============ ================================================================= ``pi`` Pi ``golden`` Golden ratio ============ ================================================================= Physical constants ================== ============= ================================================================= ``c`` 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` ``hbar`` :math:`\hbar = h/(2\pi)` ``G`` Newtonian constant of gravitation ``g`` standard acceleration of gravity ``e`` elementary charge ``R`` molar gas constant ``alpha`` fine-structure constant ``N_A`` Avogadro constant ``k`` Boltzmann constant ``sigma`` Stefan-Boltzmann constant :math:`\sigma` ``Wien`` Wien displacement law constant ``Rydberg`` Rydberg constant ``m_e`` electron mass ``m_p`` proton mass ``m_n`` neutron mass ============= ================================================================= Constants database ------------------ In addition to the above variables, :mod:`scipy.constants` also contains the 2010 CODATA recommended values [CODATA2010]_ 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}` ============ ================================================================= Weight ------ ================= ============================================================ ``gram`` :math:`10^{-3}` kg ``metric_ton`` :math:`10^{3}` kg ``grain`` one grain in kg ``lb`` one pound (avoirdupous) in kg ``oz`` 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) ================= ============================================================ Angle ----- ================= ============================================================ ``degree`` degree in radians ``arcmin`` arc minute in radians ``arcsec`` 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 ``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 ``light_year`` one light year in meters ``parsec`` one parsec in meters ================= ============================================================ Pressure -------- ================= ============================================================ ``atm`` standard atmosphere in pascals ``bar`` one bar in pascals ``torr`` 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 ``gallon`` 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_imp`` one fluid ounce (UK) in cubic meters ``bbl`` 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 ``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/ C2K K2C F2C C2F F2K K2F Energy ------ ==================== ======================================================= ``eV`` one electron volt in Joules ``calorie`` 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_th`` one British thermal unit (thermochemical) in Joules ``ton_TNT`` one ton of TNT in Joules ==================== ======================================================= Power ----- ==================== ======================================================= ``hp`` one horsepower in watts ==================== ======================================================= Force ----- ==================== ======================================================= ``dyn`` one dyne in newtons ``lbf`` one pound force in newtons ``kgf`` one kilogram force in newtons ==================== ======================================================= Optics ------ .. autosummary:: :toctree: generated/ lambda2nu nu2lambda References ========== .. [CODATA2010] CODATA Recommended Values of the Fundamental Physical Constants 2010. http://physics.nist.gov/cuu/Constants/index.html """ 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 numpy.testing import Tester test = Tester().test