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r""" |
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================================== |
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Constants (:mod:`scipy.constants`) |
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================================== |
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.. currentmodule:: scipy.constants |
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Physical and mathematical constants and units. |
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Mathematical constants |
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====================== |
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================ ================================================================= |
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``pi`` Pi |
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``golden`` Golden ratio |
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``golden_ratio`` Golden ratio |
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================ ================================================================= |
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Physical constants |
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================== |
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The following physical constants are available as attributes of `scipy.constants`. |
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All units are `SI <https://en.wikipedia.org/wiki/International_System_of_Units>`_. |
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=========================== ================================================================ =============== |
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Attribute Quantity Units |
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=========================== ================================================================ =============== |
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``c`` speed of light in vacuum m s^-1 |
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``speed_of_light`` speed of light in vacuum m s^-1 |
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``mu_0`` the magnetic constant :math:`\mu_0` N A^-2 |
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``epsilon_0`` the electric constant (vacuum permittivity), :math:`\epsilon_0` F m^-1 |
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``h`` the Planck constant :math:`h` J Hz^-1 |
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``Planck`` the Planck constant :math:`h` J Hz^-1 |
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``hbar`` the reduced Planck constant, :math:`\hbar = h/(2\pi)` J s |
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``G`` Newtonian constant of gravitation m^3 kg^-1 s^-2 |
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``gravitational_constant`` Newtonian constant of gravitation m^3 kg^-1 s^-2 |
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``g`` standard acceleration of gravity m s^-2 |
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``e`` elementary charge C |
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``elementary_charge`` elementary charge C |
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``R`` molar gas constant J mol^-1 K^-1 |
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``gas_constant`` molar gas constant J mol^-1 K^-1 |
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``alpha`` fine-structure constant (unitless) |
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``fine_structure`` fine-structure constant (unitless) |
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``N_A`` Avogadro constant mol^-1 |
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``Avogadro`` Avogadro constant mol^-1 |
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``k`` Boltzmann constant J K^-1 |
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``Boltzmann`` Boltzmann constant J K^-1 |
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``sigma`` Stefan-Boltzmann constant :math:`\sigma` W m^-2 K^-4 |
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``Stefan_Boltzmann`` Stefan-Boltzmann constant :math:`\sigma` W m^-2 K^-4 |
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``Wien`` Wien wavelength displacement law constant m K |
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``Rydberg`` Rydberg constant m^-1 |
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``m_e`` electron mass kg |
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``electron_mass`` electron mass kg |
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``m_p`` proton mass kg |
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``proton_mass`` proton mass kg |
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``m_n`` neutron mass kg |
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``neutron_mass`` neutron mass kg |
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=========================== ================================================================ =============== |
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Constants database |
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------------------ |
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In addition to the above variables, :mod:`scipy.constants` also contains the |
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2022 CODATA recommended values [CODATA2022]_ database containing more physical |
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constants. |
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.. autosummary:: |
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:toctree: generated/ |
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value -- Value in physical_constants indexed by key |
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unit -- Unit in physical_constants indexed by key |
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precision -- Relative precision in physical_constants indexed by key |
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find -- Return list of physical_constant keys with a given string |
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ConstantWarning -- Constant sought not in newest CODATA data set |
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.. data:: physical_constants |
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Dictionary of physical constants, of the format |
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``physical_constants[name] = (value, unit, uncertainty)``. |
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The CODATA database uses ellipses to indicate that a value is defined |
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(exactly) in terms of others but cannot be represented exactly with the |
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allocated number of digits. In these cases, SciPy calculates the derived |
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value and reports it to the full precision of a Python ``float``. Although |
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``physical_constants`` lists the uncertainty as ``0.0`` to indicate that |
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the CODATA value is exact, the value in ``physical_constants`` is still |
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subject to the truncation error inherent in double-precision representation. |
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Available constants: |
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====================================================================== ==== |
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%(constant_names)s |
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====================================================================== ==== |
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Units |
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===== |
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SI prefixes |
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----------- |
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============ ================================================================= |
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``quetta`` :math:`10^{30}` |
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``ronna`` :math:`10^{27}` |
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``yotta`` :math:`10^{24}` |
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``zetta`` :math:`10^{21}` |
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``exa`` :math:`10^{18}` |
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``peta`` :math:`10^{15}` |
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``tera`` :math:`10^{12}` |
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``giga`` :math:`10^{9}` |
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``mega`` :math:`10^{6}` |
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``kilo`` :math:`10^{3}` |
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``hecto`` :math:`10^{2}` |
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``deka`` :math:`10^{1}` |
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``deci`` :math:`10^{-1}` |
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``centi`` :math:`10^{-2}` |
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``milli`` :math:`10^{-3}` |
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``micro`` :math:`10^{-6}` |
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``nano`` :math:`10^{-9}` |
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``pico`` :math:`10^{-12}` |
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``femto`` :math:`10^{-15}` |
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``atto`` :math:`10^{-18}` |
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``zepto`` :math:`10^{-21}` |
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``yocto`` :math:`10^{-24}` |
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``ronto`` :math:`10^{-27}` |
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``quecto`` :math:`10^{-30}` |
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============ ================================================================= |
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Binary prefixes |
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--------------- |
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============ ================================================================= |
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``kibi`` :math:`2^{10}` |
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``mebi`` :math:`2^{20}` |
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``gibi`` :math:`2^{30}` |
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``tebi`` :math:`2^{40}` |
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``pebi`` :math:`2^{50}` |
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``exbi`` :math:`2^{60}` |
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``zebi`` :math:`2^{70}` |
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``yobi`` :math:`2^{80}` |
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============ ================================================================= |
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Mass |
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---- |
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================= ============================================================ |
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``gram`` :math:`10^{-3}` kg |
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``metric_ton`` :math:`10^{3}` kg |
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``grain`` one grain in kg |
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``lb`` one pound (avoirdupous) in kg |
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``pound`` one pound (avoirdupous) in kg |
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``blob`` one inch version of a slug in kg (added in 1.0.0) |
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``slinch`` one inch version of a slug in kg (added in 1.0.0) |
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``slug`` one slug in kg (added in 1.0.0) |
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``oz`` one ounce in kg |
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``ounce`` one ounce in kg |
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``stone`` one stone in kg |
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``grain`` one grain in kg |
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``long_ton`` one long ton in kg |
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``short_ton`` one short ton in kg |
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``troy_ounce`` one Troy ounce in kg |
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``troy_pound`` one Troy pound in kg |
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``carat`` one carat in kg |
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``m_u`` atomic mass constant (in kg) |
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``u`` atomic mass constant (in kg) |
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``atomic_mass`` atomic mass constant (in kg) |
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================= ============================================================ |
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Angle |
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----- |
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================= ============================================================ |
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``degree`` degree in radians |
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``arcmin`` arc minute in radians |
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``arcminute`` arc minute in radians |
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``arcsec`` arc second in radians |
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``arcsecond`` arc second in radians |
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================= ============================================================ |
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Time |
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---- |
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================= ============================================================ |
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``minute`` one minute in seconds |
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``hour`` one hour in seconds |
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``day`` one day in seconds |
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``week`` one week in seconds |
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``year`` one year (365 days) in seconds |
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``Julian_year`` one Julian year (365.25 days) in seconds |
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================= ============================================================ |
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Length |
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------ |
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===================== ============================================================ |
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``inch`` one inch in meters |
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``foot`` one foot in meters |
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``yard`` one yard in meters |
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``mile`` one mile in meters |
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``mil`` one mil in meters |
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``pt`` one point in meters |
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``point`` one point in meters |
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``survey_foot`` one survey foot in meters |
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``survey_mile`` one survey mile in meters |
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``nautical_mile`` one nautical mile in meters |
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``fermi`` one Fermi in meters |
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``angstrom`` one Angstrom in meters |
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``micron`` one micron in meters |
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``au`` one astronomical unit in meters |
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``astronomical_unit`` one astronomical unit in meters |
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``light_year`` one light year in meters |
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``parsec`` one parsec in meters |
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===================== ============================================================ |
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Pressure |
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-------- |
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================= ============================================================ |
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``atm`` standard atmosphere in pascals |
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``atmosphere`` standard atmosphere in pascals |
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``bar`` one bar in pascals |
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``torr`` one torr (mmHg) in pascals |
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``mmHg`` one torr (mmHg) in pascals |
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``psi`` one psi in pascals |
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================= ============================================================ |
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Area |
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---- |
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================= ============================================================ |
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``hectare`` one hectare in square meters |
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``acre`` one acre in square meters |
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================= ============================================================ |
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Volume |
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------ |
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=================== ======================================================== |
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``liter`` one liter in cubic meters |
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``litre`` one liter in cubic meters |
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``gallon`` one gallon (US) in cubic meters |
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``gallon_US`` one gallon (US) in cubic meters |
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``gallon_imp`` one gallon (UK) in cubic meters |
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``fluid_ounce`` one fluid ounce (US) in cubic meters |
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``fluid_ounce_US`` one fluid ounce (US) in cubic meters |
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``fluid_ounce_imp`` one fluid ounce (UK) in cubic meters |
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``bbl`` one barrel in cubic meters |
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``barrel`` one barrel in cubic meters |
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=================== ======================================================== |
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Speed |
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----- |
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================== ========================================================== |
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``kmh`` kilometers per hour in meters per second |
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``mph`` miles per hour in meters per second |
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``mach`` one Mach (approx., at 15 C, 1 atm) in meters per second |
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``speed_of_sound`` one Mach (approx., at 15 C, 1 atm) in meters per second |
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``knot`` one knot in meters per second |
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================== ========================================================== |
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Temperature |
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----------- |
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===================== ======================================================= |
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``zero_Celsius`` zero of Celsius scale in Kelvin |
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``degree_Fahrenheit`` one Fahrenheit (only differences) in Kelvins |
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===================== ======================================================= |
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.. autosummary:: |
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:toctree: generated/ |
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convert_temperature |
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Energy |
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------ |
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==================== ======================================================= |
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``eV`` one electron volt in Joules |
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``electron_volt`` one electron volt in Joules |
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``calorie`` one calorie (thermochemical) in Joules |
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``calorie_th`` one calorie (thermochemical) in Joules |
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``calorie_IT`` one calorie (International Steam Table calorie, 1956) in Joules |
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``erg`` one erg in Joules |
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``Btu`` one British thermal unit (International Steam Table) in Joules |
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``Btu_IT`` one British thermal unit (International Steam Table) in Joules |
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``Btu_th`` one British thermal unit (thermochemical) in Joules |
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``ton_TNT`` one ton of TNT in Joules |
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==================== ======================================================= |
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Power |
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----- |
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==================== ======================================================= |
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``hp`` one horsepower in watts |
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``horsepower`` one horsepower in watts |
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==================== ======================================================= |
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Force |
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----- |
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==================== ======================================================= |
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``dyn`` one dyne in newtons |
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``dyne`` one dyne in newtons |
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``lbf`` one pound force in newtons |
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``pound_force`` one pound force in newtons |
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``kgf`` one kilogram force in newtons |
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``kilogram_force`` one kilogram force in newtons |
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==================== ======================================================= |
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Optics |
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------ |
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.. autosummary:: |
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:toctree: generated/ |
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lambda2nu |
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nu2lambda |
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References |
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========== |
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.. [CODATA2022] CODATA Recommended Values of the Fundamental |
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Physical Constants 2022. |
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https://physics.nist.gov/cuu/Constants/ |
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""" |
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from ._codata import * |
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from ._constants import * |
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from ._codata import _obsolete_constants, physical_constants |
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from . import codata, constants |
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_constant_names_list = [(_k.lower(), _k, _v) |
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for _k, _v in physical_constants.items() |
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if _k not in _obsolete_constants] |
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_constant_names = "\n".join(["``{}``{} {} {}".format(_x[1], " "*(66-len(_x[1])), |
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_x[2][0], _x[2][1]) |
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for _x in sorted(_constant_names_list)]) |
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if __doc__: |
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__doc__ = __doc__ % dict(constant_names=_constant_names) |
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del _constant_names |
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del _constant_names_list |
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__all__ = [s for s in dir() if not s.startswith('_')] |
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from scipy._lib._testutils import PytestTester |
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test = PytestTester(__name__) |
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del PytestTester |
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