def _create_evalf_table():
global evalf_table
from sympy.functions.combinatorial.numbers import bernoulli
from sympy.concrete.products import Product
from sympy.concrete.summations import Sum
from sympy.core.add import Add
from sympy.core.mul import Mul
from sympy.core.numbers import Exp1, Float, Half, ImaginaryUnit, Integer, NaN, NegativeOne, One, Pi, Rational, Zero
from sympy.core.power import Pow
from sympy.core.symbol import Dummy, Symbol
from sympy.functions.elementary.complexes import Abs, im, re
from sympy.functions.elementary.exponential import exp, log
from sympy.functions.elementary.integers import ceiling, floor
from sympy.functions.elementary.piecewise import Piecewise
from sympy.functions.elementary.trigonometric import atan, cos, sin
from sympy.integrals.integrals import Integral
evalf_table = {
Symbol: evalf_symbol,
Dummy: evalf_symbol,
Float: lambda x, prec, options: (x._mpf_, None, prec, None),
Rational: lambda x, prec, options: (from_rational(x.p, x.q, prec), None, prec, None),
Integer: lambda x, prec, options: (from_int(x.p, prec), None, prec, None),
Zero: lambda x, prec, options: (None, None, prec, None),
One: lambda x, prec, options: (fone, None, prec, None),
Half: lambda x, prec, options: (fhalf, None, prec, None),
Pi: lambda x, prec, options: (mpf_pi(prec), None, prec, None),
Exp1: lambda x, prec, options: (mpf_e(prec), None, prec, None),
ImaginaryUnit: lambda x, prec, options: (None, fone, None, prec),
NegativeOne: lambda x, prec, options: (fnone, None, prec, None),
NaN: lambda x, prec, options: (fnan, None, prec, None),
exp: lambda x, prec, options: evalf_pow(
Pow(S.Exp1, x.args[0], evaluate=False), prec, options),
cos: evalf_trig,
sin: evalf_trig,
Add: evalf_add,
Mul: evalf_mul,
Pow: evalf_pow,
log: evalf_log,
atan: evalf_atan,
Abs: evalf_abs,
re: evalf_re,
im: evalf_im,
floor: evalf_floor,
ceiling: evalf_ceiling,
Integral: evalf_integral,
Sum: evalf_sum,
Product: evalf_prod,
Piecewise: evalf_piecewise,
bernoulli: evalf_bernoulli,
}
def _create_evalf_table():
global evalf_table
from sympy.functions.combinatorial.numbers import bernoulli
from sympy.concrete.products import Product
from sympy.concrete.summations import Sum
from sympy.core.add import Add
from sympy.core.mul import Mul
from sympy.core.numbers import Exp1, Float, Half, ImaginaryUnit, Integer, NaN, NegativeOne, One, Pi, Rational, Zero
from sympy.core.power import Pow
from sympy.core.symbol import Dummy, Symbol
from sympy.functions.elementary.complexes import Abs, im, re
from sympy.functions.elementary.exponential import exp, log
from sympy.functions.elementary.integers import ceiling, floor
from sympy.functions.elementary.piecewise import Piecewise
from sympy.functions.elementary.trigonometric import atan, cos, sin
from sympy.integrals.integrals import Integral
evalf_table = {
Symbol: evalf_symbol,
Dummy: evalf_symbol,
Float: lambda x, prec, options: (x._mpf_, None, prec, None),
Rational: lambda x, prec, options: (from_rational(x.p, x.q, prec), None, prec, None),
Integer: lambda x, prec, options: (from_int(x.p, prec), None, prec, None),
Zero: lambda x, prec, options: (None, None, prec, None),
One: lambda x, prec, options: (fone, None, prec, None),
Half: lambda x, prec, options: (fhalf, None, prec, None),
Pi: lambda x, prec, options: (mpf_pi(prec), None, prec, None),
Exp1: lambda x, prec, options: (mpf_e(prec), None, prec, None),
ImaginaryUnit: lambda x, prec, options: (None, fone, None, prec),
NegativeOne: lambda x, prec, options: (fnone, None, prec, None),
NaN : lambda x, prec, options: (fnan, None, prec, None),
exp: lambda x, prec, options: evalf_pow(
Pow(S.Exp1, x.args[0], evaluate=False), prec, options),
cos: evalf_trig,
sin: evalf_trig,
Add: evalf_add,
Mul: evalf_mul,
Pow: evalf_pow,
log: evalf_log,
atan: evalf_atan,
Abs: evalf_abs,
re: evalf_re,
im: evalf_im,
floor: evalf_floor,
ceiling: evalf_ceiling,
Integral: evalf_integral,
Sum: evalf_sum,
Product: evalf_prod,
Piecewise: evalf_piecewise,
bernoulli: evalf_bernoulli,
}
def _create_evalf_table():
global evalf_table
from ..functions.combinatorial.numbers import bernoulli
from ..concrete.products import Product
from ..concrete.summations import Sum
from .add import Add
from .mul import Mul
from .numbers import (Exp1, Float, Half, ImaginaryUnit,
Integer, NaN, NegativeOne, One, Pi,
Rational, Zero)
from .power import Pow
from .symbol import Dummy, Symbol
from ..functions.elementary.complexes import Abs, im, re
from ..functions.elementary.exponential import log
from ..functions.elementary.piecewise import Piecewise
from ..functions.elementary.trigonometric import atan, cos, sin
from ..integrals.integrals import Integral
evalf_table = {
Symbol: evalf_symbol,
Dummy: evalf_symbol,
Float: lambda x, prec, options: (x._mpf_, None, prec if prec <= x._prec else x._prec, None),
Rational: lambda x, prec, options: (from_rational(x.numerator, x.denominator, prec),
None, prec, None),
Integer: lambda x, prec, options: (from_int(x.numerator, prec),
None, prec, None),
Zero: lambda x, prec, options: (None, None, prec, None),
One: lambda x, prec, options: (fone, None, prec, None),
Half: lambda x, prec, options: (fhalf, None, prec, None),
Pi: lambda x, prec, options: (mpf_pi(prec), None, prec, None),
Exp1: lambda x, prec, options: (mpf_e(prec), None, prec, None),
ImaginaryUnit: lambda x, prec, options: (None, fone, None, prec),
NegativeOne: lambda x, prec, options: (fnone, None, prec, None),
NaN: lambda x, prec, options: (fnan, None, prec, None),
cos: evalf_trig,
sin: evalf_trig,
Add: evalf_add,
Mul: evalf_mul,
Pow: evalf_pow,
log: evalf_log,
atan: evalf_atan,
Abs: evalf_abs,
re: evalf_re,
im: evalf_im,
Integral: evalf_integral,
Sum: evalf_sum,
Product: evalf_prod,
Piecewise: evalf_piecewise,
bernoulli: evalf_bernoulli,
}
def _create_evalf_table():
global evalf_table
from ..functions.combinatorial.numbers import bernoulli
from ..concrete.products import Product
from ..concrete.summations import Sum
from .add import Add
from .mul import Mul
from .numbers import (Exp1, Float, Half, ImaginaryUnit,
Integer, NaN, NegativeOne, One, Pi,
Rational, Zero)
from .power import Pow
from .symbol import Dummy, Symbol
from ..functions.elementary.complexes import Abs, im, re
from ..functions.elementary.exponential import log
from ..functions.elementary.piecewise import Piecewise
from ..functions.elementary.trigonometric import atan, cos, sin
from ..integrals.integrals import Integral
evalf_table = {
Symbol: evalf_symbol,
Dummy: evalf_symbol,
Float: lambda x, prec, options: (x._mpf_, None, prec if prec <= x._prec else x._prec, None),
Rational: lambda x, prec, options: (from_rational(x.numerator, x.denominator, prec),
None, prec, None),
Integer: lambda x, prec, options: (from_int(x.numerator, prec),
None, prec, None),
Zero: lambda x, prec, options: (None, None, prec, None),
One: lambda x, prec, options: (fone, None, prec, None),
Half: lambda x, prec, options: (fhalf, None, prec, None),
Pi: lambda x, prec, options: (mpf_pi(prec), None, prec, None),
Exp1: lambda x, prec, options: (mpf_e(prec), None, prec, None),
ImaginaryUnit: lambda x, prec, options: (None, fone, None, prec),
NegativeOne: lambda x, prec, options: (fnone, None, prec, None),
NaN: lambda x, prec, options: (fnan, None, prec, None),
cos: evalf_trig,
sin: evalf_trig,
Add: evalf_add,
Mul: evalf_mul,
Pow: evalf_pow,
log: evalf_log,
atan: evalf_atan,
Abs: evalf_abs,
re: evalf_re,
im: evalf_im,
Integral: evalf_integral,
Sum: evalf_sum,
Product: evalf_prod,
Piecewise: evalf_piecewise,
bernoulli: evalf_bernoulli,
}
def npartitions(n, verbose=False):
"""
Calculate the partition function P(n), i.e. the number of ways that
n can be written as a sum of positive integers.
P(n) is computed using the Hardy-Ramanujan-Rademacher formula [1]_.
The correctness of this implementation has been tested through 10**10.
Examples
========
>>> from sympy.ntheory import npartitions
>>> npartitions(25)
1958
References
==========
.. [1] http://mathworld.wolfram.com/PartitionFunctionP.html
"""
n = int(n)
if n < 0:
return 0
if n <= 5:
return [1, 1, 2, 3, 5, 7][n]
if '_factor' not in globals():
_pre()
# Estimate number of bits in p(n). This formula could be tidied
pbits = int((
math.pi*(2*n/3.)**0.5 -
math.log(4*n))/math.log(10) + 1) * \
math.log(10, 2)
prec = p = int(pbits*1.1 + 100)
s = fzero
M = max(6, int(0.24*n**0.5 + 4))
if M > 10**5:
raise ValueError("Input too big") # Corresponds to n > 1.7e11
sq23pi = mpf_mul(mpf_sqrt(from_rational(2, 3, p), p), mpf_pi(p), p)
sqrt8 = mpf_sqrt(from_int(8), p)
for q in range(1, M):
a = _a(n, q, p)
d = _d(n, q, p, sq23pi, sqrt8)
s = mpf_add(s, mpf_mul(a, d), prec)
if verbose:
print("step", q, "of", M, to_str(a, 10), to_str(d, 10))
# On average, the terms decrease rapidly in magnitude.
# Dynamically reducing the precision greatly improves
# performance.
p = bitcount(abs(to_int(d))) + 50
return int(to_int(mpf_add(s, fhalf, prec)))
def npartitions(n, verbose=False):
"""
Calculate the partition function P(n), i.e. the number of ways that
n can be written as a sum of positive integers.
P(n) is computed using the Hardy-Ramanujan-Rademacher formula [1]_.
The correctness of this implementation has been tested through 10**10.
Examples
========
>>> from sympy.ntheory import npartitions
>>> npartitions(25)
1958
References
==========
.. [1] http://mathworld.wolfram.com/PartitionFunctionP.html
"""
n = int(n)
if n < 0:
return 0
if n <= 5:
return [1, 1, 2, 3, 5, 7][n]
if '_factor' not in globals():
_pre()
# Estimate number of bits in p(n). This formula could be tidied
pbits = int((
math.pi*(2*n/3.)**0.5 -
math.log(4*n))/math.log(10) + 1) * \
math.log(10, 2)
prec = p = int(pbits * 1.1 + 100)
s = fzero
M = max(6, int(0.24 * n**0.5 + 4))
if M > 10**5:
raise ValueError("Input too big") # Corresponds to n > 1.7e11
sq23pi = mpf_mul(mpf_sqrt(from_rational(2, 3, p), p), mpf_pi(p), p)
sqrt8 = mpf_sqrt(from_int(8), p)
for q in range(1, M):
a = _a(n, q, p)
d = _d(n, q, p, sq23pi, sqrt8)
s = mpf_add(s, mpf_mul(a, d), prec)
if verbose:
print("step", q, "of", M, to_str(a, 10), to_str(d, 10))
# On average, the terms decrease rapidly in magnitude.
# Dynamically reducing the precision greatly improves
# performance.
p = bitcount(abs(to_int(d))) + 50
return int(to_int(mpf_add(s, fhalf, prec)))
def _d(n, j, prec, sq23pi, sqrt8):
"""
Compute the sinh term in the outer sum of the HRR formula.
The constants sqrt(2/3*pi) and sqrt(8) must be precomputed.
"""
j = from_int(j)
pi = mpf_pi(prec)
a = mpf_div(sq23pi, j, prec)
b = mpf_sub(from_int(n), from_rational(1, 24, prec), prec)
c = mpf_sqrt(b, prec)
ch, sh = mpf_cosh_sinh(mpf_mul(a, c), prec)
D = mpf_div(mpf_sqrt(j, prec), mpf_mul(mpf_mul(sqrt8, b), pi), prec)
E = mpf_sub(mpf_mul(a, ch), mpf_div(sh, c, prec), prec)
return mpf_mul(D, E)
def _d(n, j, prec, sq23pi, sqrt8):
"""
Compute the sinh term in the outer sum of the HRR formula.
The constants sqrt(2/3*pi) and sqrt(8) must be precomputed.
"""
j = from_int(j)
pi = mpf_pi(prec)
a = mpf_div(sq23pi, j, prec)
b = mpf_sub(from_int(n), from_rational(1, 24, prec), prec)
c = mpf_sqrt(b, prec)
ch, sh = mpf_cosh_sinh(mpf_mul(a, c), prec)
D = mpf_div(mpf_sqrt(j, prec), mpf_mul(mpf_mul(sqrt8, b), pi), prec)
E = mpf_sub(mpf_mul(a, ch), mpf_div(sh, c, prec), prec)
return mpf_mul(D, E)
def npartitions(n):
"""Calculate the partition function P(n), i.e. the number of ways that
n can be written as a sum of positive integers.
P(n) is computed using the Hardy-Ramanujan-Rademacher formula.
The correctness of this implementation has been tested for 10**n
up to n = 8.
Examples
========
>>> npartitions(25)
1958
References
==========
* https://mathworld.wolfram.com/PartitionFunctionP.html
"""
n = int(n)
if n < 0:
return 0
if n <= 5:
return [1, 1, 2, 3, 5, 7][n]
# Estimate number of bits in p(n). This formula could be tidied
pbits = int((math.pi*(2*n/3.)**0.5 - math.log(4*n))/math.log(10) + 1) * \
math.log(10, 2)
prec = p = int(pbits * 1.1 + 100)
s = fzero
M = max(6, int(0.24 * n**0.5 + 4))
sq23pi = mpf_mul(mpf_sqrt(from_rational(2, 3, p), p), mpf_pi(p), p)
sqrt8 = mpf_sqrt(from_int(8), p)
for q in range(1, M):
a = _a(n, q, p)
d = _d(n, q, p, sq23pi, sqrt8)
s = mpf_add(s, mpf_mul(a, d), prec)
debug('step', q, 'of', M, to_str(a, 10), to_str(d, 10))
# On average, the terms decrease rapidly in magnitude. Dynamically
# reducing the precision greatly improves performance.
p = bitcount(abs(to_int(d))) + 50
return int(to_int(mpf_add(s, fhalf, prec)))
def _create_evalf_table():
global evalf_table
evalf_table = {
C.Symbol: evalf_symbol,
C.Dummy: evalf_symbol,
C.Float: lambda x, prec, options: (x._mpf_, None, prec, None),
C.Rational: lambda x, prec, options: (from_rational(x.p, x.q, prec), None, prec, None),
C.Integer: lambda x, prec, options: (from_int(x.p, prec), None, prec, None),
C.Zero: lambda x, prec, options: (None, None, prec, None),
C.One: lambda x, prec, options: (fone, None, prec, None),
C.Half: lambda x, prec, options: (fhalf, None, prec, None),
C.Pi: lambda x, prec, options: (mpf_pi(prec), None, prec, None),
C.Exp1: lambda x, prec, options: (mpf_e(prec), None, prec, None),
C.ImaginaryUnit: lambda x, prec, options: (None, fone, None, prec),
C.NegativeOne: lambda x, prec, options: (fnone, None, prec, None),
C.NaN : lambda x, prec, options: (fnan, None, prec, None),
C.exp: lambda x, prec, options: evalf_pow(C.Pow(S.Exp1, x.args[0],
evaluate=False), prec, options),
C.cos: evalf_trig,
C.sin: evalf_trig,
C.Add: evalf_add,
C.Mul: evalf_mul,
C.Pow: evalf_pow,
C.log: evalf_log,
C.atan: evalf_atan,
C.Abs: evalf_abs,
C.re: evalf_re,
C.im: evalf_im,
C.floor: evalf_floor,
C.ceiling: evalf_ceiling,
C.Integral: evalf_integral,
C.Sum: evalf_sum,
C.Product: evalf_prod,
C.Piecewise: evalf_piecewise,
C.bernoulli: evalf_bernoulli,
}
def npartitions(n):
"""Calculate the partition function P(n), i.e. the number of ways that
n can be written as a sum of positive integers.
P(n) is computed using the Hardy-Ramanujan-Rademacher formula.
The correctness of this implementation has been tested for 10**n
up to n = 8.
Examples
========
>>> npartitions(25)
1958
References
==========
* http://mathworld.wolfram.com/PartitionFunctionP.html
"""
n = int(n)
if n < 0:
return 0
if n <= 5:
return [1, 1, 2, 3, 5, 7][n]
# Estimate number of bits in p(n). This formula could be tidied
pbits = int((math.pi*(2*n/3.)**0.5 - math.log(4*n))/math.log(10) + 1) * \
math.log(10, 2)
prec = p = int(pbits*1.1 + 100)
s = fzero
M = max(6, int(0.24*n**0.5 + 4))
sq23pi = mpf_mul(mpf_sqrt(from_rational(2, 3, p), p), mpf_pi(p), p)
sqrt8 = mpf_sqrt(from_int(8), p)
for q in range(1, M):
a = _a(n, q, p)
d = _d(n, q, p, sq23pi, sqrt8)
s = mpf_add(s, mpf_mul(a, d), prec)
debug("step", q, "of", M, to_str(a, 10), to_str(d, 10))
# On average, the terms decrease rapidly in magnitude. Dynamically
# reducing the precision greatly improves performance.
p = bitcount(abs(to_int(d))) + 50
return int(to_int(mpf_add(s, fhalf, prec)))
