##################################################################
## (c) Copyright 2015- by Jaron T. Krogel ##
##################################################################
#====================================================================#
# unit_converter.py #
# Support for physical unit conversion of scalars and arrays. #
# Several distance, time, mass, energy, charge, pressure, and #
# force units are supported. #
# #
# Content summary: #
# convert #
# User-facing function to convert a scalar or array from one #
# unit system to another. #
# #
# UnitConverter #
# Class performs unit conversion. Wrapped by convert function. #
# #
#====================================================================#
from .developer import DevBase, obj, error
[docs]
class Unit(DevBase):
unit_dicts = obj(all=obj())
def __init__(self,type,name,symbol,value,shift=0):
self.type = type
self.name = name
self.symbol = symbol
self.value = value
self.shift = shift
ud = Unit.unit_dicts
if type not in ud:
ud[type] = obj()
#end if
td = ud[type]
td[symbol] = self
ud.all[symbol] = self
#end def __init__
#end class Unit
[docs]
class UnitConverter(DevBase):
unassigned = None
kb = 1.3806503e-23 #J/K
# count
mol = 6.0221415e23
# distance
m = 1.e0
A = 1.e-10*m
B = .52917720859e-10*m
nm = 1.e-9*m
pm = 1.e-12*m
fm = 1.e-15*m
# time
s = 1.e0
ms = 1.e-3*s
ns = 1.e-9*s
ps = 1.e-12*s
fs = 1.e-15*s
# mass
kg = 1.e0
me = 9.10938291e-31*kg
mp = 1.672621777e-27*kg
amu = 1.660538921e-27*kg
Da = amu
# energy
J = 1.e0
eV = 1.60217646e-19*J
Ry = 13.6056923*eV
Ha = 2*Ry
kJ_mol = 1000.*J/mol
kcal_mol = 0.04336411531*eV
K = kb
degC = K
degF = 5./9.*K
degC_shift = -273.15
degF_shift = 9./5*degC_shift+32
# charge
C = 1.e0
e = 1.60217646e-19*C
# pressure
Pa = 1.e0
bar = 1.e5*Pa
Mbar = 1.e6*bar
GPa = 1.e9*Pa
atm = 1.01325e5*Pa
# force
N = 1.e0
pN = 1e-12*N
# thermal conductivity
W_mK = 1.0
meter = Unit('distance' ,'meter' ,'m' ,m )
angstrom = Unit('distance' ,'Angstrom' ,'A' ,A )
bohr = Unit('distance' ,'Bohr' ,'B' ,B )
nanometer = Unit('distance' ,'nanometer' ,'nm' ,nm )
picometer = Unit('distance' ,'picometer' ,'pm' ,pm )
femtometer = Unit('distance' ,'femtometer' ,'pm' ,fm )
second = Unit('time' ,'second' ,'s' ,s )
millisecond = Unit('time' ,'millisecond' ,'ms' ,ms )
nanosecond = Unit('time' ,'nanosecond' ,'ns' ,ns )
picosecond = Unit('time' ,'picosecond' ,'ps' ,ps )
femtosecond = Unit('time' ,'femtosecond' ,'fs' ,fs )
kilogram = Unit('mass' ,'kilogram' ,'kg' ,kg )
electron_mass = Unit('mass' ,'electron mass' ,'me' ,me )
proton_mass = Unit('mass' ,'proton mass' ,'mp' ,mp )
atomic_mass_unit = Unit('mass' ,'atomic mass unit','amu' ,amu )
dalton = Unit('mass' ,'Dalton' ,'Da' ,Da )
joule = Unit('energy' ,'Joule' ,'J' ,J )
electron_volt = Unit('energy' ,'electron Volt' ,'eV' ,eV )
rydberg = Unit('energy' ,'Rydberg' ,'Ry' ,Ry )
hartree = Unit('energy' ,'Hartree' ,'Ha' ,Ha )
kJ_mole = Unit('energy' ,'kJ_mole' ,'kJ_mol' ,kJ_mol )
kcal_mole = Unit('energy' ,'kcal_mole' ,'kcal_mol',kcal_mol )
kelvin = Unit('energy' ,'Kelvin' ,'K' ,K )
celsius = Unit('energy' ,'Celsius' ,'degC' ,degC,degC_shift)
fahrenheit = Unit('energy' ,'Fahrenheit' ,'degF' ,degF,degF_shift)
coulomb = Unit('charge' ,'Coulomb' ,'C' ,C )
electron_charge = Unit('charge' ,'electron charge' ,'e' ,e )
pascal = Unit('pressure' ,'Pascal' ,'Pa' ,Pa )
bar = Unit('pressure' ,'bar' ,'bar' ,bar )
megabar = Unit('pressure' ,'megabar' ,'Mbar' ,Mbar )
gigapascal = Unit('pressure' ,'gigaPascal' ,'Gpa' ,GPa )
atmosphere = Unit('pressure' ,'atmosphere' ,'atm' ,atm )
newton = Unit('force' ,'Newton' ,'N' ,N )
piconewton = Unit('force' ,'picoNewton' ,'pN' ,pN )
W_per_mK = Unit('therm_cond','W/(m*K)' ,'W_mK' ,W_mK )
distance_dict = Unit.unit_dicts.distance
mass_dict = Unit.unit_dicts.mass
energy_dict = Unit.unit_dicts.energy
charge_dict = Unit.unit_dicts.charge
pressure_dict = Unit.unit_dicts.pressure
force_dict = Unit.unit_dicts.force
therm_cond_dict = Unit.unit_dicts.therm_cond
unit_dict = Unit.unit_dicts.all
def __init__(self):
self.error('UnitConverter should not be instantiated')
#def __init__
[docs]
@staticmethod
def convert(value,source_unit,target_unit):
ui = UnitConverter.unit_dict[source_unit]
uo = UnitConverter.unit_dict[target_unit]
if(ui.type != uo.type):
error('in UnitConverter.convert()\ntype conversion attempted between '+ui.type+' and '+uo.type)
else:
value_out = (value-ui.shift)*ui.value/uo.value+uo.shift
#end if
return (value_out,target_unit)
#end def convert
[docs]
@staticmethod
def convert_scalar_to_all(units,value_orig):
unit_type = UnitConverter.unit_dict[units].type
value = dict()
value['orig'] = value_orig
for k,u in UnitConverter.unit_dict.items():
if(u.type == unit_type and u.value!=UnitConverter.unassigned):
(value[k],utmp) = UnitConverter.convert(value['orig'],units,k)
#end if
#end for
return value
#end def convert_scalar_to_all
#end class UnitConverter
[docs]
def convert(value,source_unit,target_unit):
return UnitConverter.convert(value,source_unit,target_unit)[0]
#end def convert
