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numbers.py
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numbers.py
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import sympy.mpmath as mpmath
import sympy.mpmath.libmpf as mlib
import sympy.mpmath.libmpc as mlibc
from sympy.mpmath.libelefun import mpf_pow, mpf_pi, phi_fixed
import decimal
rnd = mlib.round_nearest
from basic import Basic, Atom, S, C, SingletonMeta, Memoizer, MemoizerArg
from sympify import _sympify, SympifyError, _sympifyit
from power import integer_nthroot
# from mul import Mul /cyclic/
# from power import Pow /cyclic/
# from function import FunctionClass /cyclic/
_errdict = {"divide": False}
def seterr(divide=False):
"""
Should sympy raise an exception on 0/0 or return a nan?
divide == True .... raise an exception
divide == False ... return nan
"""
_errdict["divide"] = divide
# (a,b) -> gcd(a,b)
_gcdcache = {}
# TODO caching with decorator, but not to degrade performance
def igcd(a, b):
"""Computes integer greates common divisor of two numbers.
The algorithm is based on the well known Euclid's algorithm. To
improve speed, igcd() has its own caching mechanizm implemented.
"""
try:
return _gcdcache[(a,b)]
except KeyError:
if a and b:
if b < 0:
b = -b
while b:
a, b = b, a % b
else:
a = abs(a or b)
_gcdcache[(a,b)] = a
return a
def ilcm(a, b):
"""Computes integer least common multiple of two numbers. """
if a == 0 and b == 0:
return 0
else:
return a * b // igcd(a, b)
def igcdex(a, b):
"""Returns x, y, g such that g = x*a + y*b = gcd(a, b).
>>> igcdex(2, 3)
(-1, 1, 1)
>>> igcdex(10, 12)
(-1, 1, 2)
>>> x, y, g = igcdex(100, 2004)
>>> x, y, g
(-20, 1, 4)
>>> x*100 + y*2004
4
"""
if (not a) and (not b):
return (0, 1, 0)
if not a:
return (0, b//abs(b), abs(b))
if not b:
return (a//abs(a), 0, abs(a))
if a < 0:
a, x_sign = -a, -1
else:
x_sign = 1
if b < 0:
b, y_sign = -b, -1
else:
y_sign = 1
x, y, r, s = 1, 0, 0, 1
while b:
(c, q) = (a % b, a // b)
(a, b, r, s, x, y) = (b, c, x-q*r, y-q*s, r, s)
return (x*x_sign, y*y_sign, a)
@Memoizer((int, long), return_value_converter = lambda d: d.copy())
def factor_trial_division(n):
"""
Factor any integer into a product of primes, 0, 1, and -1.
Returns a dictionary {<prime: exponent>}.
"""
if not n:
return {0:1}
factors = {}
if n < 0:
factors[-1] = 1
n = -n
if n==1:
factors[1] = 1
return factors
d = 2
while n % d == 0:
try:
factors[d] += 1
except KeyError:
factors[d] = 1
n //= d
d = 3
while n > 1 and d*d <= n:
if n % d:
d += 2
else:
try:
factors[d] += 1
except KeyError:
factors[d] = 1
n //= d
if n>1:
try:
factors[n] += 1
except KeyError:
factors[n] = 1
return factors
class Number(Atom):
"""
Represents any kind of number in sympy.
Floating point numbers are represented by the Real class.
Integer numbers (of any size), together with rational numbers (again, there
is no limit on their size) are represented by the Rational class.
If you want to represent for example 1+sqrt(2), then you need to do:
Rational(1) + sqrt(Rational(2))
"""
is_commutative = True
is_comparable = True
is_bounded = True
is_finite = True
__slots__ = []
# Used to make max(x._prec, y._prec) return x._prec when only x is a float
_prec = -1
is_Number = True
def __new__(cls, *obj):
if len(obj)==1: obj=obj[0]
if isinstance(obj, (int, long)):
return Integer(obj)
if isinstance(obj,tuple) and len(obj)==2:
return Rational(*obj)
if isinstance(obj, (str,float,mpmath.mpf,decimal.Decimal)):
return Real(obj)
if isinstance(obj, Number):
return obj
raise TypeError("expected str|int|long|float|Decimal|Number object but got %r" % (obj))
def _as_mpf_val(self, prec):
"""Evaluate to mpf tuple accurate to at least prec bits"""
raise NotImplementedError('%s needs ._as_mpf_val() method' % \
(self.__class__.__name__))
def _eval_evalf(self, prec):
return Real._new(self._as_mpf_val(prec), prec)
def _as_mpf_op(self, prec):
prec = max(prec, self._prec)
return self._as_mpf_val(prec), prec
def __float__(self):
return mlib.to_float(self._as_mpf_val(53))
def _eval_derivative(self, s):
return S.Zero
def _eval_conjugate(self):
return self
def _eval_order(self, *symbols):
# Order(5, x, y) -> Order(1,x,y)
return C.Order(S.One, *symbols)
def __eq__(self, other):
raise NotImplementedError('%s needs .__eq__() method' % (self.__class__.__name__))
def __ne__(self, other):
raise NotImplementedError('%s needs .__ne__() method' % (self.__class__.__name__))
def __lt__(self, other):
raise NotImplementedError('%s needs .__lt__() method' % (self.__class__.__name__))
def __le__(self, other):
raise NotImplementedError('%s needs .__le__() method' % (self.__class__.__name__))
def __gt__(self, other):
return _sympify(other).__lt__(self)
def __ge__(self, other):
return _sympify(other).__le__(self)
def as_coeff_terms(self, x=None):
# a -> c * t
return self, tuple()
class Real(Number):
"""
Represents a floating point number. It is capable of representing
arbitrary-precision floating-point numbers
Usage:
======
Real(3.5) .... 3.5 (the 3.5 was converted from a python float)
Real("3.0000000000000005")
Notes:
======
- Real(x) with x being a Python int/long will return Integer(x)
"""
is_real = True
is_irrational = False
is_integer = False
__slots__ = ['_mpf_', '_prec']
# mpz can't be pickled
def __getnewargs__(self):
return (mlib.to_pickable(self._mpf_),)
def __getstate__(self):
d = Basic.__getstate__(self).copy()
del d["_mpf_"]
return mlib.to_pickable(self._mpf_), d
def __setstate__(self, state):
_mpf_, d = state
_mpf_ = mlib.from_pickable(_mpf_)
self._mpf_ = _mpf_
Basic.__setstate__(self, d)
is_Real = True
def floor(self):
return C.Integer(int(mlib.to_int(mlib.mpf_floor(self._mpf_, self._prec))))
def ceiling(self):
return C.Integer(int(mlib.to_int(mlib.mpf_ceil(self._mpf_, self._prec))))
@property
def num(self):
return mpmath.mpf(self._mpf_)
def _as_mpf_val(self, prec):
return self._mpf_
def _as_mpf_op(self, prec):
return self._mpf_, max(prec, self._prec)
def __new__(cls, num, prec=15):
prec = mpmath.settings.dps_to_prec(prec)
if isinstance(num, (int, long)):
return Integer(num)
if isinstance(num, (str, decimal.Decimal)):
_mpf_ = mlib.from_str(str(num), prec, rnd)
elif isinstance(num, tuple) and len(num) == 4:
_mpf_ = num
else:
_mpf_ = mpmath.mpf(num)._mpf_
if not num:
return C.Zero()
obj = Basic.__new__(cls)
obj._mpf_ = _mpf_
obj._prec = prec
return obj
@classmethod
def _new(cls, _mpf_, _prec):
if _mpf_ == mlib.fzero:
return S.Zero
obj = Basic.__new__(cls)
obj._mpf_ = _mpf_
obj._prec = _prec
return obj
def _hashable_content(self):
return (self._mpf_, self._prec)
def _eval_is_positive(self):
return self.num > 0
def _eval_is_negative(self):
return self.num < 0
def __neg__(self):
return Real._new(mlib.mpf_neg(self._mpf_), self._prec)
def __mul__(self, other):
try:
other = _sympify(other)
except SympifyError:
return NotImplemented
if isinstance(other, Number):
rhs, prec = other._as_mpf_op(self._prec)
return Real._new(mlib.mpf_mul(self._mpf_, rhs, prec, rnd), prec)
return Number.__mul__(self, other)
def __add__(self, other):
try:
other = _sympify(other)
except SympifyError:
return NotImplemented
if (other is S.NaN) or (self is NaN):
return S.NaN
if isinstance(other, Number):
rhs, prec = other._as_mpf_op(self._prec)
return Real._new(mlib.mpf_add(self._mpf_, rhs, prec, rnd), prec)
return Number.__add__(self, other)
def _eval_power(b, e):
"""
b is Real but not equal to rationals, integers, 0.5, oo, -oo, nan
e is symbolic object but not equal to 0, 1
(-p) ** r -> exp(r * log(-p)) -> exp(r * (log(p) + I*Pi)) ->
-> p ** r * (sin(Pi*r) + cos(Pi*r) * I)
"""
if isinstance(e, Number):
if isinstance(e, Integer):
prec = b._prec
return Real._new(mlib.mpf_pow_int(b._mpf_, e.p, prec, rnd), prec)
e, prec = e._as_mpf_op(b._prec)
b = b._mpf_
try:
y = mpf_pow(b, e, prec, rnd)
return Real._new(y, prec)
except mlib.ComplexResult:
re, im = mlibc.mpc_pow((b, mlib.fzero), (e, mlib.fzero), prec, rnd)
return Real._new(re, prec) + Real._new(im, prec) * S.ImaginaryUnit
def __abs__(self):
return Real._new(mlib.mpf_abs(self._mpf_), self._prec)
def __int__(self):
return int(mlib.to_int(self._mpf_))
def __eq__(self, other):
try:
other = _sympify(other)
except SympifyError:
return False # sympy != other --> not ==
if isinstance(other, NumberSymbol):
if other.is_irrational: return False
return other.__eq__(self)
if other.is_comparable: other = other.evalf()
if isinstance(other, Number):
return bool(mlib.mpf_eq(self._mpf_, other._as_mpf_val(self._prec)))
return False # Real != non-Number
def __ne__(self, other):
try:
other = _sympify(other)
except SympifyError:
return True # sympy != other
if isinstance(other, NumberSymbol):
if other.is_irrational: return True
return other.__ne__(self)
if other.is_comparable: other = other.evalf()
if isinstance(other, Number):
return bool(not mlib.mpf_eq(self._mpf_, other._as_mpf_val(self._prec)))
return True # Real != non-Number
def __lt__(self, other):
try:
other = _sympify(other)
except SympifyError:
return False # sympy > other
if isinstance(other, NumberSymbol):
return other.__ge__(self)
if other.is_comparable: other = other.evalf()
if isinstance(other, Number):
return bool(mlib.mpf_lt(self._mpf_, other._as_mpf_val(self._prec)))
return Basic.__lt__(self, other)
def __le__(self, other):
try:
other = _sympify(other)
except SympifyError:
return False # sympy > other --> ! <=
if isinstance(other, NumberSymbol):
return other.__gt__(self)
if other.is_comparable: other = other.evalf()
if isinstance(other, Number):
return bool(mlib.mpf_le(self._mpf_, other._as_mpf_val(self._prec)))
return Basic.__le__(self, other)
def epsilon_eq(self, other, epsilon="10e-16"):
return abs(self - other) < Real(epsilon)
def _sage_(self):
import sage.all as sage
return sage.RealNumber(str(self))
# this is here to work nicely in Sage
RealNumber = Real
def _parse_rational(s):
"""Parse rational number from string representation"""
# Simple fraction
if "/" in s:
p, q = s.split("/")
return int(p), int(q)
# Recurring decimal
elif "[" in s:
sign = 1
if s[0] == "-":
sign = -1
s = s[1:]
s, periodic = s.split("[")
periodic = periodic.rstrip("]")
offset = len(s) - s.index(".") - 1
n1 = int(periodic)
n2 = int("9" * len(periodic))
r = Rational(*_parse_rational(s)) + Rational(n1, n2*10**offset)
return sign*r.p, r.q
# Ordinary decimal string. Use the Decimal class's built-in parser
else:
sign, digits, expt = decimal.Decimal(s).as_tuple()
p = (1, -1)[sign] * int("".join(str(x) for x in digits))
if expt >= 0:
return p*(10**expt), 1
else:
return p, 10**-expt
class Rational(Number):
"""Represents integers and rational numbers (p/q) of any size.
Examples
========
>>> Rational(3)
3
>>> Rational(1,2)
1/2
You can create a rational from a string:
>>> Rational("3/5")
3/5
>>> Rational("1.23")
123/100
Use square brackets to indicate a recurring decimal:
>>> Rational("0.[333]")
1/3
>>> Rational("1.2[05]")
1193/990
>>> float(Rational(1193,990))
1.20505050505
Low-level
---------
Access nominator and denominator as .p and .q:
>>> r = Rational(3,4)
>>> r
3/4
>>> r.p
3
>>> r.q
4
"""
is_real = True
is_integer = False
is_rational = True
__slots__ = ['p', 'q']
is_Rational = True
@Memoizer(type, (int, long, str, 'Integer'), MemoizerArg((int, long, 'Integer', type(None)), name="q"))
def __new__(cls, p, q = None):
if q is None:
if isinstance(p, str):
p, q = _parse_rational(p)
else:
return Integer(p)
if q==0:
if p==0:
if _errdict["divide"]:
raise ValueError("Indeterminate 0/0")
else:
return S.NaN
if p<0: return S.NegativeInfinity
return S.Infinity
if q<0:
q = -q
p = -p
n = igcd(abs(p), q)
if n>1:
p //= n
q //= n
if q==1: return Integer(p)
if p==1 and q==2: return S.Half
obj = Basic.__new__(cls)
obj.p = int(p)
obj.q = int(q)
#obj._args = (p, q)
return obj
def __getnewargs__(self):
return (self.p, self.q)
def _hashable_content(self):
return (self.p, self.q)
def _eval_is_positive(self):
return self.p > 0
def _eval_is_zero(self):
return self.p == 0
def __neg__(self): return Rational(-self.p, self.q)
@_sympifyit('other', NotImplemented)
def __mul__(self, other):
if (other is S.NaN) or (self is S.NaN):
return S.NaN
if isinstance(other, Real):
return other * self
if isinstance(other, Rational):
return Rational(self.p * other.p, self.q * other.q)
return Number.__mul__(self, other)
# TODO reorder
@_sympifyit('other', NotImplemented)
def __add__(self, other):
if (other is S.NaN) or (self is S.NaN):
return S.NaN
if isinstance(other, Real):
return other + self
if isinstance(other, Rational):
if self.is_unbounded:
if other.is_bounded:
return self
elif self==other:
return self
else:
if other.is_unbounded:
return other
return Rational(self.p * other.q + self.q * other.p, self.q * other.q)
return Number.__add__(self, other)
def _eval_power(b, e):
if (e is S.NaN): return S.NaN
if isinstance(e, Number):
if isinstance(e, Real):
return b._eval_evalf(e._prec) ** e
if e.is_negative:
# (3/4)**-2 -> (4/3)**2
ne = -e
if (ne is S.One):
return Rational(b.q, b.p)
return Rational(b.q, b.p) ** ne
if (e is S.Infinity):
if b.p > b.q:
# (3/2)**oo -> oo
return S.Infinity
if b.p < -b.q:
# (-3/2)**oo -> oo + I*oo
return S.Infinity + S.Infinity * S.ImaginaryUnit
return S.Zero
if isinstance(e, Integer):
# (4/3)**2 -> 4**2 / 3**2
return Rational(b.p ** e.p, b.q ** e.p)
if isinstance(e, Rational):
if b.p != 1:
# (4/3)**(5/6) -> 4**(5/6) * 3**(-5/6)
return Integer(b.p) ** e * Integer(b.q) ** (-e)
if b >= 0:
return Integer(b.q)**Rational(e.p * (e.q-1), e.q) / ( Integer(b.q) ** Integer(e.p))
else:
return (-1)**e * (-b)**e
c,t = b.as_coeff_terms()
if e.is_even and isinstance(c, Number) and c < 0:
return (-c * Mul(*t)) ** e
return
def _as_mpf_val(self, prec):
return mlib.from_rational(self.p, self.q, prec, rnd)
def __abs__(self):
return Rational(abs(self.p), self.q)
def __int__(self):
return int(self.p//self.q)
def __eq__(self, other):
try:
other = _sympify(other)
except SympifyError:
return False # sympy != other --> not ==
if isinstance(other, NumberSymbol):
if other.is_irrational: return False
return other.__eq__(self)
if isinstance(self, Number) and isinstance(other, FunctionClass):
return False
if other.is_comparable and not isinstance(other, Rational): other = other.evalf()
if isinstance(other, Number):
if isinstance(other, Real):
return bool(mlib.mpf_eq(self._as_mpf_val(other._prec), other._mpf_))
return bool(self.p==other.p and self.q==other.q)
return False # Rational != non-Number
def __ne__(self, other):
try:
other = _sympify(other)
except SympifyError:
return True # sympy != other
if isinstance(other, NumberSymbol):
if other.is_irrational: return True
return other.__ne__(self)
if other.is_comparable and not isinstance(other, Rational): other = other.evalf()
if isinstance(other, Number):
if isinstance(other, Real):
return bool(not mlib.feq(self._as_mpf_val(other._prec), other._mpf_))
return bool(self.p!=other.p or self.q!=other.q)
return True # Rational != non-Number
def __lt__(self, other):
try:
other = _sympify(other)
except SympifyError:
return False # sympy > other --> not <
if isinstance(other, NumberSymbol):
return other.__ge__(self)
if other.is_comparable and not isinstance(other, Rational): other = other.evalf()
if isinstance(other, Number):
if isinstance(other, Real):
return bool(mlib.mpf_lt(self._as_mpf_val(other._prec), other._mpf_))
return bool(self.p * other.q < self.q * other.p)
return Basic.__lt__(self, other)
def __le__(self, other):
try:
other = _sympify(other)
except SympifyError:
return False # sympy > other --> not <=
if isinstance(other, NumberSymbol):
return other.__gt__(self)
if other.is_comparable and not isinstance(other, Rational): other = other.evalf()
if isinstance(other, Number):
if isinstance(other, Real):
return bool(mlib.mpf_le(self._as_mpf_val(other._prec), other._mpf_))
return bool(self.p * other.q <= self.q * other.p)
return Basic.__le__(self, other)
def factors(self):
f = factor_trial_division(self.p).copy()
for p,e in factor_trial_division(self.q).items():
try: f[p] += -e
except KeyError: f[p] = -e
if len(f)>1 and 1 in f: del f[1]
return f
def as_numer_denom(self):
return Integer(self.p), Integer(self.q)
def _sage_(self):
import sage.all as sage
#XXX: fixme, this should work:
#return sage.Integer(self[0])/sage.Integer(self[1])
return sage.Integer(self.p)/sage.Integer(self.q)
# int -> Integer
_intcache = {}
# TODO move this tracing facility to sympy/core/trace.py ?
def _intcache_printinfo():
ints = sorted(_intcache.keys())
nhit = _intcache_hits
nmiss= _intcache_misses
if nhit == 0 and nmiss == 0:
print
print 'Integer cache statistic was not collected'
return
miss_ratio = float(nmiss) / (nhit+nmiss)
print
print 'Integer cache statistic'
print '-----------------------'
print
print '#items: %i' % len(ints)
print
print ' #hit #miss #total'
print
print '%5i %5i (%7.5f %%) %5i' % (nhit, nmiss, miss_ratio*100, nhit+nmiss)
print
print ints
_intcache_hits = 0
_intcache_misses = 0
def int_trace(f):
import os
if os.getenv('SYMPY_TRACE_INT', 'no').lower() != 'yes':
return f
def Integer_tracer(cls, i):
global _intcache_hits, _intcache_misses
try:
_intcache_hits += 1
return _intcache[i]
except KeyError:
_intcache_hits -= 1
_intcache_misses += 1
return f(cls, i)
# also we want to hook our _intcache_printinfo into sys.atexit
import atexit
atexit.register(_intcache_printinfo)
return Integer_tracer
class Integer(Rational):
q = 1
is_integer = True
is_Integer = True
__slots__ = ['p']
def _as_mpf_val(self, prec):
return mlib.from_int(self.p)
# TODO caching with decorator, but not to degrade performance
@int_trace
def __new__(cls, i):
try:
return _intcache[i]
except KeyError:
# The most often situation is when Integers are created from Python
# int or long
if isinstance(i, (int, long)):
obj = Basic.__new__(cls)
obj.p = i
_intcache[i] = obj
return obj
# Also, we seldomly need the following to work:
# UC: Integer(Integer(4)) <-- sympify('4')
elif isinstance(i, Integer):
return i
else:
raise ValueError('invalid argument for Integer: %r' % (i,))
def __getnewargs__(self):
return (self.p,)
# Arithmetic operations are here for efficiency
def __int__(self):
return self.p
def __neg__(self):
return Integer(-self.p)
def __abs__(self):
if self.p >= 0:
return self
else:
return Integer(-self.p)
def __mod__(self, other):
return self.p % other
def __rmod__(self, other):
return other % self.p
# TODO make it decorator + bytecodehacks?
def __add__(a, b):
if type(b) is int:
return Integer(a.p + b)
elif isinstance(b, Integer):
return Integer(a.p + b.p)
return Rational.__add__(a, b) # a,b -not- b,a
def __radd__(a, b):
if type(b) is int:
return Integer(b + a.p)
elif isinstance(b, Integer):
return Integer(b.p + a.p)
return Rational.__add__(a, b)
def __sub__(a, b):
if type(b) is int:
return Integer(a.p - b)
elif isinstance(b, Integer):
return Integer(a.p - b.p)
return Rational.__sub__(a, b)
def __rsub__(a, b):
if type(b) is int:
return Integer(b - a.p)
elif isinstance(b, Integer):
return Integer(b.p - a.p)
return Rational.__rsub__(a, b)
def __mul__(a, b):
if type(b) is int:
return Integer(a.p * b)
elif isinstance(b, Integer):
return Integer(a.p * b.p)
return Rational.__mul__(a, b)
def __rmul__(a, b):
if type(b) is int:
return Integer(b * a.p)
elif isinstance(b, Integer):
return Integer(b.p * a.p)
return Rational.__mul__(a, b)
# XXX __pow__ ?
# XXX do we need to define __cmp__ ?
# def __cmp__(a, b):
def __eq__(a, b):
if type(b) is int:
return (a.p == b)
elif isinstance(b, Integer):
return (a.p == b.p)
return Rational.__eq__(a, b)
def __ne__(a, b):
if type(b) is int:
return (a.p != b)
elif isinstance(b, Integer):
return (a.p != b.p)
return Rational.__ne__(a, b)
def __gt__(a, b):
if type(b) is int:
return (a.p > b)
elif isinstance(b, Integer):
return (a.p > b.p)
return Rational.__gt__(a, b)
def __lt__(a, b):
if type(b) is int:
return (a.p < b)
elif isinstance(b, Integer):
return (a.p < b.p)
return Rational.__lt__(a, b)
def __ge__(a, b):
if type(b) is int:
return (a.p >= b)
elif isinstance(b, Integer):
return (a.p >= b.p)
return Rational.__ge__(a, b)
def __le__(a, b):
if type(b) is int:
return (a.p <= b)
elif isinstance(b, Integer):
return (a.p <= b.p)
return Rational.__le__(a, b)
########################################
def _eval_is_odd(self):
return bool(self.p % 2)
def _eval_power(base, exp):
"""
Tries to do some simplifications on base ** exp, where base is
an instance of Integer
Returns None if no further simplifications can be done
When exponent is a fraction (so we have for example a square root),
we try to find the simplest possible representation, so that
- 4**Rational(1,2) becomes 2
- (-4)**Rational(1,2) becomes 2*I
We will
"""
if exp is S.NaN: return S.NaN
if base is S.One: return S.One
if base is S.NegativeOne: return
if exp is S.Infinity:
if base.p > S.One: return S.Infinity
if base.p == -1: return S.NaN
# cases 0, 1 are done in their respective classes
return S.Infinity + S.ImaginaryUnit * S.Infinity
if not isinstance(exp, Number):
# simplify when exp is even
# (-2) ** k --> 2 ** k
c,t = base.as_coeff_terms()
if exp.is_even and isinstance(c, Number) and c < 0:
return (-c * Mul(*t)) ** exp
if not isinstance(exp, Rational): return
if exp is S.Half and base < 0:
# we extract I for this special case since everyone is doing so
return S.ImaginaryUnit * Pow(-base, exp)
result = None
if exp < 0:
# invert base and change sign on exponent
return Rational(1, base.p) ** (-exp)
# see if base is a perfect root, sqrt(4) --> 2
x, xexact = integer_nthroot(abs(base.p), exp.q)
if xexact:
# if it's a perfect root we've finished
result = Integer(x ** abs(exp.p))
if exp < 0: result = 1/result
if base < 0: result *= (-1)**exp
return result
# The following is an algorithm where we collect perfect roots
# from the factors of base
if base > 4294967296:
# Prevent from factorizing too big integers
return None
dict = base.factors()
out_int = 1
sqr_int = 1
sqr_gcd = 0
sqr_dict = {}
for prime,exponent in dict.iteritems():
exponent *= exp.p
div_e = exponent // exp.q
div_m = exponent % exp.q
if div_e > 0:
out_int *= prime**div_e
if div_m > 0:
sqr_dict[prime] = div_m
for p,ex in sqr_dict.iteritems():
if sqr_gcd == 0:
sqr_gcd = ex
else:
sqr_gcd = igcd(sqr_gcd, ex)
for k,v in sqr_dict.iteritems():
sqr_int *= k**(v // sqr_gcd)
if sqr_int == base.p and out_int == 1:
result = None
else:
result = out_int * Pow(sqr_int , Rational(sqr_gcd, exp.q))
return result
def _eval_is_prime(self):
if self.p < 0:
return False
def as_numer_denom(self):
return self, S.One
def __floordiv__(self, other):
return Integer(self.p // Integer(other).p)
def __rfloordiv__(self, other):
return Integer(Integer(other).p // self.p)
class Zero(Integer):
__metaclass__ = SingletonMeta
p = 0
q = 1
is_positive = False
is_negative = False
is_finite = False
is_zero = True
is_prime = False