| 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 |
| ================== |
| The following physical constants are available as attributes of `scipy.constants`. |
| All units are `SI <https://en.wikipedia.org/wiki/International_System_of_Units>`_. |
| |
| =========================== ================================================================ =============== |
| Attribute Quantity Units |
| =========================== ================================================================ =============== |
| ``c`` speed of light in vacuum m s^-1 |
| ``speed_of_light`` speed of light in vacuum m s^-1 |
| ``mu_0`` the magnetic constant :math:`\mu_0` N A^-2 |
| ``epsilon_0`` the electric constant (vacuum permittivity), :math:`\epsilon_0` F m^-1 |
| ``h`` the Planck constant :math:`h` J Hz^-1 |
| ``Planck`` the Planck constant :math:`h` J Hz^-1 |
| ``hbar`` the reduced Planck constant, :math:`\hbar = h/(2\pi)` J s |
| ``G`` Newtonian constant of gravitation m^3 kg^-1 s^-2 |
| ``gravitational_constant`` Newtonian constant of gravitation m^3 kg^-1 s^-2 |
| ``g`` standard acceleration of gravity m s^-2 |
| ``e`` elementary charge C |
| ``elementary_charge`` elementary charge C |
| ``R`` molar gas constant J mol^-1 K^-1 |
| ``gas_constant`` molar gas constant J mol^-1 K^-1 |
| ``alpha`` fine-structure constant (unitless) |
| ``fine_structure`` fine-structure constant (unitless) |
| ``N_A`` Avogadro constant mol^-1 |
| ``Avogadro`` Avogadro constant mol^-1 |
| ``k`` Boltzmann constant J K^-1 |
| ``Boltzmann`` Boltzmann constant J K^-1 |
| ``sigma`` Stefan-Boltzmann constant :math:`\sigma` W m^-2 K^-4 |
| ``Stefan_Boltzmann`` Stefan-Boltzmann constant :math:`\sigma` W m^-2 K^-4 |
| ``Wien`` Wien wavelength displacement law constant m K |
| ``Rydberg`` Rydberg constant m^-1 |
| ``m_e`` electron mass kg |
| ``electron_mass`` electron mass kg |
| ``m_p`` proton mass kg |
| ``proton_mass`` proton mass kg |
| ``m_n`` neutron mass kg |
| ``neutron_mass`` neutron mass kg |
| =========================== ================================================================ =============== |
| |
| |
| Constants database |
| ------------------ |
| |
| In addition to the above variables, :mod:`scipy.constants` also contains the |
| 2022 CODATA recommended values [CODATA2022]_ 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)``. |
| The CODATA database uses ellipses to indicate that a value is defined |
| (exactly) in terms of others but cannot be represented exactly with the |
| allocated number of digits. In these cases, SciPy calculates the derived |
| value and reports it to the full precision of a Python ``float``. Although |
| ``physical_constants`` lists the uncertainty as ``0.0`` to indicate that |
| the CODATA value is exact, the value in ``physical_constants`` is still |
| subject to the truncation error inherent in double-precision representation. |
| |
| Available constants: |
| |
| ====================================================================== ==== |
| %(constant_names)s |
| ====================================================================== ==== |
| |
| |
| Units |
| ===== |
| |
| SI prefixes |
| ----------- |
| |
| ============ ================================================================= |
| ``quetta`` :math:`10^{30}` |
| ``ronna`` :math:`10^{27}` |
| ``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}` |
| ``yocto`` :math:`10^{-24}` |
| ``ronto`` :math:`10^{-27}` |
| ``quecto`` :math:`10^{-30}` |
| ============ ================================================================= |
| |
| 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 |
| ========== |
| |
| .. [CODATA2022] CODATA Recommended Values of the Fundamental |
| Physical Constants 2022. |
| |
| https://physics.nist.gov/cuu/Constants/ |
| |
| """ |
| |
| from ._codata import * |
| from ._constants import * |
| from ._codata import _obsolete_constants, physical_constants |
|
|
| |
| from . import codata, constants |
|
|
| _constant_names_list = [(_k.lower(), _k, _v) |
| for _k, _v in physical_constants.items() |
| if _k not in _obsolete_constants] |
| _constant_names = "\n".join(["``{}``{} {} {}".format(_x[1], " "*(66-len(_x[1])), |
| _x[2][0], _x[2][1]) |
| for _x in sorted(_constant_names_list)]) |
| if __doc__: |
| __doc__ = __doc__ % dict(constant_names=_constant_names) |
|
|
| del _constant_names |
| del _constant_names_list |
|
|
| __all__ = [s for s in dir() if not s.startswith('_')] |
|
|
| from scipy._lib._testutils import PytestTester |
| test = PytestTester(__name__) |
| del PytestTester |
|
|
