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# -*- coding: utf-8 -*-
"""
For information and usage see README, or http://pypi.python.org/pypi/numericalunits
"""
#Copyright (C) 2012 Steven Byrnes
#
#Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
#
#The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
#
#THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
from math import pi
import random
__version__ = 1.13
def reset_units(seed=None):
"""
Set all units to new, self-consistent, floating-point values. See package
documentation for detailed explanation and examples:
http://pypi.python.org/pypi/numericalunits
reset_units() --> units are randomized. This is the suggested use. Run this
before your calculation, display the final answer, then re-run this, then
re-disply the final answer. If you get the same answers both times, then
your calculations are almost guaranteed to be free of
dimensional-analysis-violating errors. reset_units() is run automatically
the first time this module is imported.
reset_units('SI') --> Set units so that all values are given in standard SI
units (meters-kilograms-seconds) by default. In this mode, there is no way
to test for dimensional-analysis-violating errors.
reset_units(x) --> If you pass any other argument x, it's used as the seed
for the random number generator.
"""
global m, kg, s, C, K
if seed == 'SI':
m = 1.
kg = 1.
s = 1.
C = 1.
K = 1.
else:
prior_random_state = random.getstate()
if seed is None:
random.seed()
else:
random.seed(seed)
m = 10. ** random.uniform(-1,1) #meter
kg = 10. ** random.uniform(-1,1) #kilogram
s = 10. ** random.uniform(-1,1) #second
C = 10. ** random.uniform(-1,1) # coulombs
K = 10. ** random.uniform(-1,1) # kelvins
# Leave the random generator like I found it, in case something else is
# using it.
random.setstate(prior_random_state)
set_derived_units_and_constants()
return
def set_derived_units_and_constants():
"""
Assuming that the base units (m, kg, s, C, K) have already been set as
floating-point values, this function sets all other units and constants
to the appropriate, self-consistent values.
"""
# Length
global cm, mm, um, nm, pm, fm, km, angstrom, lightyear, \
astro_unit, pc, kpc, Mpc, Gpc, inch, foot, mile, thou
cm = 1e-2 * m
mm = 1e-3 * m
um = 1e-6 * m
nm = 1e-9 * m
pm = 1e-12 * m
fm = 1e-15 * m
km = 1e3 * m
angstrom = 1e-10 * m
lightyear = 9460730472580800. * m
astro_unit = 149597870700. * m #astronomical unit
pc = (648000./pi) * astro_unit; #parsec
kpc = 1e3 * pc
Mpc = 1e6 * pc
Gpc = 1e9 * pc
inch = 2.54 * cm
foot = 12. * inch
mile = 5280. * foot
thou = 1e-3 * inch #thousandth of an inch; also called mil
# Volume
global L, mL, uL, nL, pL, fL, aL, kL, ML, GL
L = 1e-3 * m**3 #liter
mL = 1e-3 * L
uL = 1e-6 * L
nL = 1e-9 * L
pL = 1e-12 * L
fL = 1e-15 * L
aL = 1e-18 * L
kL = 1e3 * L
ML = 1e6 * L
GL = 1e9 * L
# Time
global ms, us, ns, ps, fs, minute, hour, day, week, year
ms = 1e-3 * s
us = 1e-6 * s
ns = 1e-9 * s
ps = 1e-12 * s
fs = 1e-15 * s
minute = 60. * s
hour = 60. * minute
day = 24. * hour #solar day
week = 7. * day
year = 365.256363004 * day #sidereal year
# Frequency
global Hz, mHz, kHz, MHz, GHz, THz, PHz
Hz = 1./s
mHz = 1e-3 * Hz
kHz = 1e3 * Hz
MHz = 1e6 * Hz
GHz = 1e9 * Hz
THz = 1e12 * Hz
PHz = 1e15 * Hz
# Mass
global g, mg, ug, ng, pg, fg, tonne, amu, Da, kDa, lbm
g = 1e-3 * kg
mg = 1e-3 * g
ug = 1e-6 * g
ng = 1e-9 * g
pg = 1e-12 * g
fg = 1e-15 * g
tonne = 1e3 * kg
amu = 1.660538921e-27 * kg #atomic mass unit
Da = amu #Dalton
kDa = 1e3 * Da
lbm = 0.45359237 * kg # pound mass (international avoirdupois pound)
# Energy
global J, mJ, uJ, nJ, pJ, fJ, kJ, MJ, GJ, erg, eV, meV, keV, MeV, GeV, \
TeV, btu, smallcal, kcal, Wh, kWh
J = (kg * m**2)/s**2
mJ = 1e-3 * J
uJ = 1e-6 * J
nJ = 1e-9 * J
pJ = 1e-12 * J
fJ = 1e-15 * J
kJ = 1e3 * J
MJ = 1e6 * J
GJ = 1e9 * J
erg = 1e-7 * J
eV = 1.602176565e-19 * J
meV = 1e-3 * eV
keV = 1e3 * eV
MeV = 1e6 * eV
GeV = 1e9 * eV
TeV = 1e12 * eV
btu = 1055.056 * J #British thermal unit
smallcal = 4.184 * J #small calorie ("gram calorie")
kcal = 4184. * J #kilocalorie ("large Calorie", "dietary Calorie")
Wh = 3600. * J #watt-hour
kWh = 1e3 * Wh # kilowatt-hour
# Moles, concentration / molarity
global NA, mol, mmol, umol, nmol, pmol, fmol, M, mM, uM, nM, pM, fM
NA = 6.02214129e23 #Avogadro's number
mol = NA #1 mole (see README)
mmol = 1e-3 * mol
umol = 1e-6 * mol
nmol = 1e-9 * mol
pmol = 1e-12 * mol
fmol = 1e-15 * mol
M = mol/L # molar
mM = 1e-3 * M
uM = 1e-6 * M
nM = 1e-9 * M
pM = 1e-12 * M
fM = 1e-15 * M
# Force
global N, dyn, lbf
N = (kg * m)/s**2 #newton
dyn = 1e-5 * N #dyne
lbf = 4.4482216152605 * N #pound-force (international avoirdupois pound)
# Pressure
global Pa, hPa, kPa, MPa, GPa, bar, mbar, cbar, dbar, kbar, Mbar, atm, \
torr, mtorr, psi
Pa = N/m**2 #pascal
hPa = 1e2 * Pa #hectopascal
kPa = 1e3 * Pa
MPa = 1e6 * Pa
GPa = 1e9 * Pa
bar = 1e5 * Pa
mbar = 1e-3 * bar
cbar = 1e-2 * bar #centibar
dbar = 0.1 * bar #decibar
kbar = 1e3 * bar
Mbar = 1e6 * bar
atm = 101325. * Pa
torr = (1./760.) * atm
mtorr = 1e-3 * torr
psi = lbf / inch**2
# Power
global W, mW, uW, nW, pW, kW, MW, GW, TW
W = J/s
mW = 1e-3 * W
uW = 1e-6 * W
nW = 1e-9 * W
pW = 1e-12 * W
kW = 1e3 * W
MW = 1e6 * W
GW = 1e9 * W
TW = 1e12 * W
# Temperature
global degFinterval, degCinterval
degFinterval = (5./9.) * K # A temperature difference in degrees Fahrenheit
degCinterval = K # A temperature difference in degrees Celsius
# Charge
global mC, uC, nC, Ah, mAh
mC = 1e-3 * C
uC = 1e-6 * C
nC = 1e-9 * C
Ah = 3600. * C #amp-hour
mAh = 1e-3 * Ah
# Current
global A, mA, uA, nA, pA, fA
A = C/s
mA = 1e-3 * A
uA = 1e-6 * A
nA = 1e-9 * A
pA = 1e-12 * A
fA = 1e-15 * A
# Voltage
global V, mV, uV, nV, kV, MV, GV, TV
V = J/C
mV = 1e-3 * V
uV = 1e-6 * V
nV = 1e-9 * V
kV = 1e3 * V
MV = 1e6 * V
GV = 1e9 * V
TV = 1e12 * V
# Resistance and conductivity
global ohm, mohm, kohm, Mohm, Gohm, S, mS, uS, nS
ohm = V / A
mohm = 1e-3 * ohm
kohm = 1e3 * ohm
Mohm = 1e6 * ohm
Gohm = 1e9 * ohm
S = 1./ohm #siemens
mS = 1e-3 * S
uS = 1e-6 * S
nS = 1e-9 * S
# Magnetic fields and fluxes
global T, mT, uT, nT, G, mG, uG, kG, Oe, Wb
T = (V * s) / m**2 #tesla
mT = 1e-3 * T
uT = 1e-6 * T
nT = 1e-9 * T
G = 1e-4 * T #gauss
mG = 1e-3 * G
uG = 1e-6 * G
kG = 1e3 * G
Oe = (1000./(4.*pi)) * A/m #oersted
Wb = J/A #weber
# Capacitance and inductance
global F, uF, nF, pF, fF, aF, H, mH, uH, nH
F = C / V #farad
uF = 1e-6 * F
nF = 1e-9 * F
pF = 1e-12 * F
fF = 1e-15 * F
aF = 1e-18 * F
H = m**2 * kg / C**2 #henry
mH = 1e-3 * H
uH = 1e-6 * H
nH = 1e-9 * H
#Constants--general
global c0, mu0, eps0, Z0, hPlanck, hbar, kB, GNewton, sigmaSB, alphaFS
c0 = 299792458. * m/s #speed of light in vacuum
mu0 = 4. * pi * 1e-7 * N/A**2 #magnetic constant, permeability of vacuum
eps0 = 1./(mu0 * c0**2) #electric constant, permittivity of vacuum
Z0 = mu0 * c0 #vacuum impedance, 377 ohms
hPlanck = 6.62606957e-34 * J*s #planck constant
hbar = hPlanck / (2.*pi) #reduced planck constant
kB = 1.3806488e-23 * J/K #Boltzmann constant
GNewton = 6.67384e-11 * m**3 / (kg * s**2) #Gravitational constant
sigmaSB = 5.670373e-8 * W / (m**2 * K**4) #Stefan-Boltzmann constant
alphaFS = 7.2973525698e-3 #fine-structure constant
#Constants--chemistry, atomic physics, electrons
global Rgas, e, uBohr, uNuc, aBohr, me, mp, mn, Rinf, Ry, \
ARichardson, Phi0, KJos, RKlitz
Rgas = kB #ideal gas constant (see README)
e = 1.602176565e-19 * C #charge of proton
uBohr = 9.27400968e-24 * J/T #Bohr magneton
uNuc = 5.05078353e-27 * J/T #nuclear magneton
aBohr = 0.52917721092e-10 * m #Bohr radius
me = 9.10938291e-31 * kg #electron mass
mp = 1.672621777e-27 * kg #proton mass
mn = 1.674927351e-27 * kg #neutron mass
Rinf = 10973731.568539 / m #Rydberg constant
Ry = 2.179872171e-18 * J #Rydberg energy, approximately 13.6 eV
ARichardson = (4.*pi*e*me*kB**2) / hPlanck**3 #Richardson constant
Phi0 = 2.067833758e-15 * Wb #magnetic flux quantum
KJos = 4.83597870e14 * Hz / V #Josephson constant
RKlitz = 2.58128074434e4 * ohm #von Klitzing constant
#Constants--astronomical and properties of earth
global REarth, g0, Msolar, MEarth
REarth = 6371. * km #radius of earth
g0 = 9.80665 * m / s**2 #standard earth gravitational acceleration
Msolar = 1.98892e30 * kg #mass of the sun
MEarth = 5.9736e24 * kg #mass of earth
# Set units randomly when this module is initialized. (Don't worry: If the
# module is imported many times from many places, this command will only
# execute during the first import.)
reset_units()
if False: #workaround so that Spyder IDE recognizes these variables as globals
m=1
kg=1
s=1
K=1
C=1
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