def __pow__(self, other):
if self.offset != 0:
raise TypeError("cannot exponentiate units with non-zero offset")
if type(other) is int:
return PhysicalUnit(
other * self.names,
pow(self.factor, other),
#list(map(lambda x,p=other: x*p, self.powers)))
[x * other for x in self.powers])
if type(other) is float:
inv_exp = 1. / other
rounded = int(umath.floor(inv_exp + 0.5))
if abs(inv_exp - rounded) < 1.e-10:
if reduce(lambda a, b: a and b,
map(lambda x, e=rounded: x % e == 0, self.powers)):
f = pow(self.factor, other)
p = [x / rounded for x in self.powers]
if reduce(
lambda a, b: a and b,
map(lambda x, e=rounded: x % e == 0,
self.names.values())):
names = self.names / rounded
else:
names = numberdict.NumberDict(default=0)
if f != 1.:
names[str(f)] = 1
for i in range(len(p)):
names[_base_names[i]] = p[i]
return PhysicalUnit(names, f, p)
else:
raise TypeError('Illegal exponent')
raise TypeError('Only integer and inverse integer exponents allowed')
def __init__(self, names, factor, powers, offset=0):
if isinstance(names, basestring):
self.names = numberdict.NumberDict(default=0)
self.names[names] = 1
else:
self.names = names
self.factor = float(factor)
self.offset = offset
self.powers = powers
def __truediv__(self, other):
if self.offset != 0 or (isPhysicalUnit(other) and other.offset != 0):
raise TypeError("cannot divide units with non-zero offset")
if isPhysicalUnit(other):
return PhysicalUnit(self.names - other.names,
self.factor / other.factor, list(map(lambda a,b: a - b, self.powers, other.powers)))
else:
return PhysicalUnit(self.names + numberdict.NumberDict({str(other): -1}, default=0),
self.factor/float(other), self.powers)
def setName(self, name):
self.names = numberdict.NumberDict(default=0)
self.names[name] = 1
