"""
"""
from __future__ import absolute_import
import sys
import weakref
import numpy
from .dimensionality import Dimensionality
from . import markup
from .quantity import Quantity, get_conversion_factor
from .registry import unit_registry
from .decorators import memoize, with_doc
__all__ = [
'CompoundUnit', 'Dimensionless', 'UnitConstant', 'UnitCurrency',
'UnitCurrent', 'UnitInformation', 'UnitLength', 'UnitLuminousIntensity',
'UnitMass', 'UnitMass', 'UnitQuantity', 'UnitSubstance', 'UnitTemperature',
'UnitTime', 'set_default_units'
]
class UnitQuantity(Quantity):
_primary_order = 90
_secondary_order = 0
_reference_quantity = None
__array_priority__ = 20
def __new__(
cls, name, definition=None, symbol=None, u_symbol=None,
aliases=[], doc=None
):
try:
assert isinstance(name, str)
except AssertionError:
raise TypeError('name must be a string, got %s (not unicode)'%name)
try:
assert symbol is None or isinstance(symbol, str)
except AssertionError:
raise TypeError(
'symbol must be a string, '
'got %s (u_symbol can be unicode)'%symbol
)
ret = numpy.array(1, dtype='d').view(cls)
ret.flags.writeable = False
ret._name = name
ret._symbol = symbol
ret._u_symbol = u_symbol
if doc is not None:
ret.__doc__ = doc
if definition is not None:
if not isinstance(definition, Quantity):
definition *= dimensionless
ret._definition = definition
ret._conv_ref = definition._reference
else:
ret._definition = None
ret._conv_ref = None
ret._aliases = aliases
ret._format_order = (ret._primary_order, ret._secondary_order)
ret.__class__._secondary_order += 1
return ret
def __init__(
self, name, definition=None, symbol=None, u_symbol=None,
aliases=[], doc=None
):
unit_registry[name] = self
if symbol:
unit_registry[symbol] = self
for alias in aliases:
unit_registry[alias] = self
def __array_finalize__(self, obj):
pass
def __hash__(self):
return hash((type(self), self._name))
@property
def _reference(self):
if self._conv_ref is None:
return self
else:
return self._conv_ref
@property
def _dimensionality(self):
return Dimensionality({self:1})
@property
def format_order(self):
return self._format_order
@property
def name(self):
return self._name
@property
def definition(self):
if self._definition is None:
return self
else:
return self._definition
@property
def simplified(self):
return self._reference.simplified
@property
def symbol(self):
if self._symbol:
return self._symbol
else:
return self.name
@property
def u_symbol(self):
if self._u_symbol:
return self._u_symbol
else:
return self.symbol
@property
def units(self):
return self
@units.setter
def units(self, units):
raise AttributeError('can not modify protected units')
def __repr__(self):
ref = self._definition
if ref:
ref = ', %s * %s'%(str(ref.magnitude), ref.dimensionality.string)
else:
ref = ''
symbol = self._symbol
symbol = ', %s'%(repr(symbol)) if symbol else ''
if markup.config.use_unicode:
u_symbol = self._u_symbol
u_symbol = ', %s'%(repr(u_symbol)) if u_symbol else ''
else:
u_symbol = ''
return '%s(%s%s%s%s)'%(
self.__class__.__name__, repr(self.name), ref, symbol, u_symbol
)
@with_doc(Quantity.__str__, use_header=False)
def __str__(self):
if self.u_symbol != self.name:
if markup.config.use_unicode:
s = '1 %s (%s)'%(self.u_symbol, self.name)
else:
s = '1 %s (%s)'%(self.symbol, self.name)
else:
s = '1 %s'%self.name
return s
@with_doc(Quantity.__add__, use_header=False)
def __add__(self, other):
return self.view(Quantity).__add__(other)
@with_doc(Quantity.__radd__, use_header=False)
def __radd__(self, other):
try:
return self.rescale(other.units).__radd__(other)
except AttributeError:
return self.view(Quantity).__radd__(other)
@with_doc(Quantity.__sub__, use_header=False)
def __sub__(self, other):
return self.view(Quantity).__sub__(other)
@with_doc(Quantity.__rsub__, use_header=False)
def __rsub__(self, other):
try:
return self.rescale(other.units).__rsub__(other)
except AttributeError:
return self.view(Quantity).__rsub__(other)
@with_doc(Quantity.__mod__, use_header=False)
def __mod__(self, other):
return self.view(Quantity).__mod__(other)
@with_doc(Quantity.__rsub__, use_header=False)
def __rmod__(self, other):
try:
return self.rescale(other.units).__rmod__(other)
except AttributeError:
return self.view(Quantity).__rmod__(other)
@with_doc(Quantity.__mul__, use_header=False)
def __mul__(self, other):
return self.view(Quantity).__mul__(other)
@with_doc(Quantity.__rmul__, use_header=False)
def __rmul__(self, other):
return self.view(Quantity).__rmul__(other)
@with_doc(Quantity.__truediv__, use_header=False)
def __truediv__(self, other):
return self.view(Quantity).__truediv__(other)
@with_doc(Quantity.__rtruediv__, use_header=False)
def __rtruediv__(self, other):
return self.view(Quantity).__rtruediv__(other)
if sys.version_info[0] < 3:
@with_doc(Quantity.__div__, use_header=False)
def __div__(self, other):
return self.view(Quantity).__div__(other)
@with_doc(Quantity.__rdiv__, use_header=False)
def __rdiv__(self, other):
return self.view(Quantity).__rdiv__(other)
@with_doc(Quantity.__pow__, use_header=False)
def __pow__(self, other):
return self.view(Quantity).__pow__(other)
@with_doc(Quantity.__rpow__, use_header=False)
def __rpow__(self, other):
return self.view(Quantity).__rpow__(other)
@with_doc(Quantity.__iadd__, use_header=False)
def __iadd__(self, other):
raise TypeError('can not modify protected units')
@with_doc(Quantity.__isub__, use_header=False)
def __isub__(self, other):
raise TypeError('can not modify protected units')
@with_doc(Quantity.__imul__, use_header=False)
def __imul__(self, other):
raise TypeError('can not modify protected units')
@with_doc(Quantity.__itruediv__, use_header=False)
def __itruediv__(self, other):
raise TypeError('can not modify protected units')
if sys.version_info[0] < 3:
@with_doc(Quantity.__idiv__, use_header=False)
def __idiv__(self, other):
raise TypeError('can not modify protected units')
@with_doc(Quantity.__ipow__, use_header=False)
def __ipow__(self, other):
raise TypeError('can not modify protected units')
def __getstate__(self):
"""
Return the internal state of the quantity, for pickling
purposes.
"""
state = (1, self._format_order)
return state
def __setstate__(self, state):
ver, fo = state
self._format_order = fo
def __reduce__(self):
"""
Return a tuple for pickling a UnitQuantity.
"""
return (
type(self),
(
self._name,
self._definition,
self._symbol,
self._u_symbol,
self._aliases,
self.__doc__
),
self.__getstate__()
)
def copy(self):
return (
type(self)(
self._name,
self._definition,
self._symbol,
self._u_symbol,
self._aliases,
self.__doc__
)
)
unit_registry['UnitQuantity'] = UnitQuantity
class IrreducibleUnit(UnitQuantity):
_default_unit = None
def __init__(
self, name, definition=None, symbol=None, u_symbol=None,
aliases=[], doc=None
):
super(IrreducibleUnit, self).__init__(
name, definition, symbol, u_symbol, aliases, doc
)
cls = type(self)
if cls._default_unit is None:
cls._default_unit = self
@property
def simplified(self):
return self.view(Quantity).rescale(self.get_default_unit())
@classmethod
def get_default_unit(cls):
return cls._default_unit
@classmethod
def set_default_unit(cls, unit):
if unit is None:
return
if isinstance(unit, str):
unit = unit_registry[unit]
try:
# check that conversions are possible:
get_conversion_factor(cls._default_unit, unit)
except ValueError:
raise TypeError('default unit must be of same type')
cls._default_unit = unit
class UnitMass(IrreducibleUnit):
_primary_order = 1
class UnitLength(IrreducibleUnit):
_primary_order = 2
class UnitTime(IrreducibleUnit):
_primary_order = 3
class UnitCurrent(IrreducibleUnit):
_primary_order = 4
class UnitLuminousIntensity(IrreducibleUnit):
_primary_order = 5
class UnitSubstance(IrreducibleUnit):
_primary_order = 6
class UnitTemperature(IrreducibleUnit):
_primary_order = 7
class UnitInformation(IrreducibleUnit):
_primary_order = 8
class UnitCurrency(IrreducibleUnit):
_primary_order = 9
class CompoundUnit(UnitQuantity):
_primary_order = 99
def __new__(cls, name):
return UnitQuantity.__new__(cls, name, unit_registry[name])
def __init__(self, name):
# do not register
return
@with_doc(UnitQuantity.__add__, use_header=False)
def __repr__(self):
return '1 %s'%self.name
@property
def name(self):
if markup.config.use_unicode:
return '(%s)'%(markup.superscript(self._name))
else:
return '(%s)'%self._name
def __reduce__(self):
"""
Return a tuple for pickling a UnitQuantity.
"""
return (
type(self),
(self._name, ),
self.__getstate__()
)
def copy(self):
return type(self)(self._name)
unit_registry['CompoundUnit'] = CompoundUnit
class Dimensionless(UnitQuantity):
_primary_order = 100
def __init__(self, name, definition=None):
self._name = name
if definition is None:
definition = self
self._definition = definition
self._format_order = (self._primary_order, self._secondary_order)
self.__class__._secondary_order += 1
unit_registry[name] = self
def __reduce__(self):
"""
Return a tuple for pickling a UnitQuantity.
"""
return (
type(self),
(
self._name,
),
self.__getstate__()
)
@property
def _dimensionality(self):
return Dimensionality()
dimensionless = Dimensionless('dimensionless')
class UnitConstant(UnitQuantity):
_primary_order = 0
def __init__(
self, name, definition=None, symbol=None, u_symbol=None,
aliases=[], doc=None
):
# we dont want to register constants in the unit registry
return
def set_default_units(
system=None, currency=None, current=None, information=None, length=None,
luminous_intensity=None, mass=None, substance=None, temperature=None,
time=None
):
"""
Set the default units in which simplified quantities will be
expressed.
system sets the unit system, and can be "SI" or "cgs". All other
keyword arguments will accept either a string or a unit quantity.
An error will be raised if it is not possible to convert between
old and new defaults, so it is not possible to set "kg" as the
default unit for time.
If both system and individual defaults are given, the system
defaults will be applied first, followed by the individual ones.
"""
if system is not None:
system = system.lower()
try:
assert system in ('si', 'cgs')
except AssertionError:
raise ValueError('system must be "SI" or "cgs", got "%s"' % system)
if system == 'si':
UnitCurrent.set_default_unit('A')
UnitLength.set_default_unit('m')
UnitMass.set_default_unit('kg')
elif system == 'cgs':
UnitLength.set_default_unit('cm')
UnitMass.set_default_unit('g')
UnitLuminousIntensity.set_default_unit('cd')
UnitSubstance.set_default_unit('mol')
UnitTemperature.set_default_unit('degK')
UnitTime.set_default_unit('s')
UnitCurrency.set_default_unit(currency)
UnitCurrent.set_default_unit(current)
UnitInformation.set_default_unit(information)
UnitLength.set_default_unit(length)
UnitLuminousIntensity.set_default_unit(luminous_intensity)
UnitMass.set_default_unit(mass)
UnitSubstance.set_default_unit(substance)
UnitTemperature.set_default_unit(temperature)
UnitTime.set_default_unit(time)