ai-content-maker/.venv/Lib/site-packages/sympy/polys/tests/test_ring_series.py

636 lines
24 KiB
Python

from sympy.polys.domains import QQ, EX, RR
from sympy.polys.rings import ring
from sympy.polys.ring_series import (_invert_monoms, rs_integrate,
rs_trunc, rs_mul, rs_square, rs_pow, _has_constant_term, rs_hadamard_exp,
rs_series_from_list, rs_exp, rs_log, rs_newton, rs_series_inversion,
rs_compose_add, rs_asin, rs_atan, rs_atanh, rs_tan, rs_cot, rs_sin, rs_cos,
rs_cos_sin, rs_sinh, rs_cosh, rs_tanh, _tan1, rs_fun, rs_nth_root,
rs_LambertW, rs_series_reversion, rs_is_puiseux, rs_series)
from sympy.testing.pytest import raises, slow
from sympy.core.symbol import symbols
from sympy.functions import (sin, cos, exp, tan, cot, atan, atanh,
tanh, log, sqrt)
from sympy.core.numbers import Rational
from sympy.core import expand, S
def is_close(a, b):
tol = 10**(-10)
assert abs(a - b) < tol
def test_ring_series1():
R, x = ring('x', QQ)
p = x**4 + 2*x**3 + 3*x + 4
assert _invert_monoms(p) == 4*x**4 + 3*x**3 + 2*x + 1
assert rs_hadamard_exp(p) == x**4/24 + x**3/3 + 3*x + 4
R, x = ring('x', QQ)
p = x**4 + 2*x**3 + 3*x + 4
assert rs_integrate(p, x) == x**5/5 + x**4/2 + 3*x**2/2 + 4*x
R, x, y = ring('x, y', QQ)
p = x**2*y**2 + x + 1
assert rs_integrate(p, x) == x**3*y**2/3 + x**2/2 + x
assert rs_integrate(p, y) == x**2*y**3/3 + x*y + y
def test_trunc():
R, x, y, t = ring('x, y, t', QQ)
p = (y + t*x)**4
p1 = rs_trunc(p, x, 3)
assert p1 == y**4 + 4*y**3*t*x + 6*y**2*t**2*x**2
def test_mul_trunc():
R, x, y, t = ring('x, y, t', QQ)
p = 1 + t*x + t*y
for i in range(2):
p = rs_mul(p, p, t, 3)
assert p == 6*x**2*t**2 + 12*x*y*t**2 + 6*y**2*t**2 + 4*x*t + 4*y*t + 1
p = 1 + t*x + t*y + t**2*x*y
p1 = rs_mul(p, p, t, 2)
assert p1 == 1 + 2*t*x + 2*t*y
R1, z = ring('z', QQ)
raises(ValueError, lambda: rs_mul(p, z, x, 2))
p1 = 2 + 2*x + 3*x**2
p2 = 3 + x**2
assert rs_mul(p1, p2, x, 4) == 2*x**3 + 11*x**2 + 6*x + 6
def test_square_trunc():
R, x, y, t = ring('x, y, t', QQ)
p = (1 + t*x + t*y)*2
p1 = rs_mul(p, p, x, 3)
p2 = rs_square(p, x, 3)
assert p1 == p2
p = 1 + x + x**2 + x**3
assert rs_square(p, x, 4) == 4*x**3 + 3*x**2 + 2*x + 1
def test_pow_trunc():
R, x, y, z = ring('x, y, z', QQ)
p0 = y + x*z
p = p0**16
for xx in (x, y, z):
p1 = rs_trunc(p, xx, 8)
p2 = rs_pow(p0, 16, xx, 8)
assert p1 == p2
p = 1 + x
p1 = rs_pow(p, 3, x, 2)
assert p1 == 1 + 3*x
assert rs_pow(p, 0, x, 2) == 1
assert rs_pow(p, -2, x, 2) == 1 - 2*x
p = x + y
assert rs_pow(p, 3, y, 3) == x**3 + 3*x**2*y + 3*x*y**2
assert rs_pow(1 + x, Rational(2, 3), x, 4) == 4*x**3/81 - x**2/9 + x*Rational(2, 3) + 1
def test_has_constant_term():
R, x, y, z = ring('x, y, z', QQ)
p = y + x*z
assert _has_constant_term(p, x)
p = x + x**4
assert not _has_constant_term(p, x)
p = 1 + x + x**4
assert _has_constant_term(p, x)
p = x + y + x*z
def test_inversion():
R, x = ring('x', QQ)
p = 2 + x + 2*x**2
n = 5
p1 = rs_series_inversion(p, x, n)
assert rs_trunc(p*p1, x, n) == 1
R, x, y = ring('x, y', QQ)
p = 2 + x + 2*x**2 + y*x + x**2*y
p1 = rs_series_inversion(p, x, n)
assert rs_trunc(p*p1, x, n) == 1
R, x, y = ring('x, y', QQ)
p = 1 + x + y
raises(NotImplementedError, lambda: rs_series_inversion(p, x, 4))
p = R.zero
raises(ZeroDivisionError, lambda: rs_series_inversion(p, x, 3))
def test_series_reversion():
R, x, y = ring('x, y', QQ)
p = rs_tan(x, x, 10)
assert rs_series_reversion(p, x, 8, y) == rs_atan(y, y, 8)
p = rs_sin(x, x, 10)
assert rs_series_reversion(p, x, 8, y) == 5*y**7/112 + 3*y**5/40 + \
y**3/6 + y
def test_series_from_list():
R, x = ring('x', QQ)
p = 1 + 2*x + x**2 + 3*x**3
c = [1, 2, 0, 4, 4]
r = rs_series_from_list(p, c, x, 5)
pc = R.from_list(list(reversed(c)))
r1 = rs_trunc(pc.compose(x, p), x, 5)
assert r == r1
R, x, y = ring('x, y', QQ)
c = [1, 3, 5, 7]
p1 = rs_series_from_list(x + y, c, x, 3, concur=0)
p2 = rs_trunc((1 + 3*(x+y) + 5*(x+y)**2 + 7*(x+y)**3), x, 3)
assert p1 == p2
R, x = ring('x', QQ)
h = 25
p = rs_exp(x, x, h) - 1
p1 = rs_series_from_list(p, c, x, h)
p2 = 0
for i, cx in enumerate(c):
p2 += cx*rs_pow(p, i, x, h)
assert p1 == p2
def test_log():
R, x = ring('x', QQ)
p = 1 + x
p1 = rs_log(p, x, 4)/x**2
assert p1 == Rational(1, 3)*x - S.Half + x**(-1)
p = 1 + x +2*x**2/3
p1 = rs_log(p, x, 9)
assert p1 == -17*x**8/648 + 13*x**7/189 - 11*x**6/162 - x**5/45 + \
7*x**4/36 - x**3/3 + x**2/6 + x
p2 = rs_series_inversion(p, x, 9)
p3 = rs_log(p2, x, 9)
assert p3 == -p1
R, x, y = ring('x, y', QQ)
p = 1 + x + 2*y*x**2
p1 = rs_log(p, x, 6)
assert p1 == (4*x**5*y**2 - 2*x**5*y - 2*x**4*y**2 + x**5/5 + 2*x**4*y -
x**4/4 - 2*x**3*y + x**3/3 + 2*x**2*y - x**2/2 + x)
# Constant term in series
a = symbols('a')
R, x, y = ring('x, y', EX)
assert rs_log(x + a, x, 5) == -EX(1/(4*a**4))*x**4 + EX(1/(3*a**3))*x**3 \
- EX(1/(2*a**2))*x**2 + EX(1/a)*x + EX(log(a))
assert rs_log(x + x**2*y + a, x, 4) == -EX(a**(-2))*x**3*y + \
EX(1/(3*a**3))*x**3 + EX(1/a)*x**2*y - EX(1/(2*a**2))*x**2 + \
EX(1/a)*x + EX(log(a))
p = x + x**2 + 3
assert rs_log(p, x, 10).compose(x, 5) == EX(log(3) + Rational(19281291595, 9920232))
def test_exp():
R, x = ring('x', QQ)
p = x + x**4
for h in [10, 30]:
q = rs_series_inversion(1 + p, x, h) - 1
p1 = rs_exp(q, x, h)
q1 = rs_log(p1, x, h)
assert q1 == q
p1 = rs_exp(p, x, 30)
assert p1.coeff(x**29) == QQ(74274246775059676726972369, 353670479749588078181744640000)
prec = 21
p = rs_log(1 + x, x, prec)
p1 = rs_exp(p, x, prec)
assert p1 == x + 1
# Constant term in series
a = symbols('a')
R, x, y = ring('x, y', QQ[exp(a), a])
assert rs_exp(x + a, x, 5) == exp(a)*x**4/24 + exp(a)*x**3/6 + \
exp(a)*x**2/2 + exp(a)*x + exp(a)
assert rs_exp(x + x**2*y + a, x, 5) == exp(a)*x**4*y**2/2 + \
exp(a)*x**4*y/2 + exp(a)*x**4/24 + exp(a)*x**3*y + \
exp(a)*x**3/6 + exp(a)*x**2*y + exp(a)*x**2/2 + exp(a)*x + exp(a)
R, x, y = ring('x, y', EX)
assert rs_exp(x + a, x, 5) == EX(exp(a)/24)*x**4 + EX(exp(a)/6)*x**3 + \
EX(exp(a)/2)*x**2 + EX(exp(a))*x + EX(exp(a))
assert rs_exp(x + x**2*y + a, x, 5) == EX(exp(a)/2)*x**4*y**2 + \
EX(exp(a)/2)*x**4*y + EX(exp(a)/24)*x**4 + EX(exp(a))*x**3*y + \
EX(exp(a)/6)*x**3 + EX(exp(a))*x**2*y + EX(exp(a)/2)*x**2 + \
EX(exp(a))*x + EX(exp(a))
def test_newton():
R, x = ring('x', QQ)
p = x**2 - 2
r = rs_newton(p, x, 4)
assert r == 8*x**4 + 4*x**2 + 2
def test_compose_add():
R, x = ring('x', QQ)
p1 = x**3 - 1
p2 = x**2 - 2
assert rs_compose_add(p1, p2) == x**6 - 6*x**4 - 2*x**3 + 12*x**2 - 12*x - 7
def test_fun():
R, x, y = ring('x, y', QQ)
p = x*y + x**2*y**3 + x**5*y
assert rs_fun(p, rs_tan, x, 10) == rs_tan(p, x, 10)
assert rs_fun(p, _tan1, x, 10) == _tan1(p, x, 10)
def test_nth_root():
R, x, y = ring('x, y', QQ)
assert rs_nth_root(1 + x**2*y, 4, x, 10) == -77*x**8*y**4/2048 + \
7*x**6*y**3/128 - 3*x**4*y**2/32 + x**2*y/4 + 1
assert rs_nth_root(1 + x*y + x**2*y**3, 3, x, 5) == -x**4*y**6/9 + \
5*x**4*y**5/27 - 10*x**4*y**4/243 - 2*x**3*y**4/9 + 5*x**3*y**3/81 + \
x**2*y**3/3 - x**2*y**2/9 + x*y/3 + 1
assert rs_nth_root(8*x, 3, x, 3) == 2*x**QQ(1, 3)
assert rs_nth_root(8*x + x**2 + x**3, 3, x, 3) == x**QQ(4,3)/12 + 2*x**QQ(1,3)
r = rs_nth_root(8*x + x**2*y + x**3, 3, x, 4)
assert r == -x**QQ(7,3)*y**2/288 + x**QQ(7,3)/12 + x**QQ(4,3)*y/12 + 2*x**QQ(1,3)
# Constant term in series
a = symbols('a')
R, x, y = ring('x, y', EX)
assert rs_nth_root(x + a, 3, x, 4) == EX(5/(81*a**QQ(8, 3)))*x**3 - \
EX(1/(9*a**QQ(5, 3)))*x**2 + EX(1/(3*a**QQ(2, 3)))*x + EX(a**QQ(1, 3))
assert rs_nth_root(x**QQ(2, 3) + x**2*y + 5, 2, x, 3) == -EX(sqrt(5)/100)*\
x**QQ(8, 3)*y - EX(sqrt(5)/16000)*x**QQ(8, 3) + EX(sqrt(5)/10)*x**2*y + \
EX(sqrt(5)/2000)*x**2 - EX(sqrt(5)/200)*x**QQ(4, 3) + \
EX(sqrt(5)/10)*x**QQ(2, 3) + EX(sqrt(5))
def test_atan():
R, x, y = ring('x, y', QQ)
assert rs_atan(x, x, 9) == -x**7/7 + x**5/5 - x**3/3 + x
assert rs_atan(x*y + x**2*y**3, x, 9) == 2*x**8*y**11 - x**8*y**9 + \
2*x**7*y**9 - x**7*y**7/7 - x**6*y**9/3 + x**6*y**7 - x**5*y**7 + \
x**5*y**5/5 - x**4*y**5 - x**3*y**3/3 + x**2*y**3 + x*y
# Constant term in series
a = symbols('a')
R, x, y = ring('x, y', EX)
assert rs_atan(x + a, x, 5) == -EX((a**3 - a)/(a**8 + 4*a**6 + 6*a**4 + \
4*a**2 + 1))*x**4 + EX((3*a**2 - 1)/(3*a**6 + 9*a**4 + \
9*a**2 + 3))*x**3 - EX(a/(a**4 + 2*a**2 + 1))*x**2 + \
EX(1/(a**2 + 1))*x + EX(atan(a))
assert rs_atan(x + x**2*y + a, x, 4) == -EX(2*a/(a**4 + 2*a**2 + 1)) \
*x**3*y + EX((3*a**2 - 1)/(3*a**6 + 9*a**4 + 9*a**2 + 3))*x**3 + \
EX(1/(a**2 + 1))*x**2*y - EX(a/(a**4 + 2*a**2 + 1))*x**2 + EX(1/(a**2 \
+ 1))*x + EX(atan(a))
def test_asin():
R, x, y = ring('x, y', QQ)
assert rs_asin(x + x*y, x, 5) == x**3*y**3/6 + x**3*y**2/2 + x**3*y/2 + \
x**3/6 + x*y + x
assert rs_asin(x*y + x**2*y**3, x, 6) == x**5*y**7/2 + 3*x**5*y**5/40 + \
x**4*y**5/2 + x**3*y**3/6 + x**2*y**3 + x*y
def test_tan():
R, x, y = ring('x, y', QQ)
assert rs_tan(x, x, 9)/x**5 == \
Rational(17, 315)*x**2 + Rational(2, 15) + Rational(1, 3)*x**(-2) + x**(-4)
assert rs_tan(x*y + x**2*y**3, x, 9) == 4*x**8*y**11/3 + 17*x**8*y**9/45 + \
4*x**7*y**9/3 + 17*x**7*y**7/315 + x**6*y**9/3 + 2*x**6*y**7/3 + \
x**5*y**7 + 2*x**5*y**5/15 + x**4*y**5 + x**3*y**3/3 + x**2*y**3 + x*y
# Constant term in series
a = symbols('a')
R, x, y = ring('x, y', QQ[tan(a), a])
assert rs_tan(x + a, x, 5) == (tan(a)**5 + 5*tan(a)**3/3 +
2*tan(a)/3)*x**4 + (tan(a)**4 + 4*tan(a)**2/3 + Rational(1, 3))*x**3 + \
(tan(a)**3 + tan(a))*x**2 + (tan(a)**2 + 1)*x + tan(a)
assert rs_tan(x + x**2*y + a, x, 4) == (2*tan(a)**3 + 2*tan(a))*x**3*y + \
(tan(a)**4 + Rational(4, 3)*tan(a)**2 + Rational(1, 3))*x**3 + (tan(a)**2 + 1)*x**2*y + \
(tan(a)**3 + tan(a))*x**2 + (tan(a)**2 + 1)*x + tan(a)
R, x, y = ring('x, y', EX)
assert rs_tan(x + a, x, 5) == EX(tan(a)**5 + 5*tan(a)**3/3 +
2*tan(a)/3)*x**4 + EX(tan(a)**4 + 4*tan(a)**2/3 + EX(1)/3)*x**3 + \
EX(tan(a)**3 + tan(a))*x**2 + EX(tan(a)**2 + 1)*x + EX(tan(a))
assert rs_tan(x + x**2*y + a, x, 4) == EX(2*tan(a)**3 +
2*tan(a))*x**3*y + EX(tan(a)**4 + 4*tan(a)**2/3 + EX(1)/3)*x**3 + \
EX(tan(a)**2 + 1)*x**2*y + EX(tan(a)**3 + tan(a))*x**2 + \
EX(tan(a)**2 + 1)*x + EX(tan(a))
p = x + x**2 + 5
assert rs_atan(p, x, 10).compose(x, 10) == EX(atan(5) + S(67701870330562640) / \
668083460499)
def test_cot():
R, x, y = ring('x, y', QQ)
assert rs_cot(x**6 + x**7, x, 8) == x**(-6) - x**(-5) + x**(-4) - \
x**(-3) + x**(-2) - x**(-1) + 1 - x + x**2 - x**3 + x**4 - x**5 + \
2*x**6/3 - 4*x**7/3
assert rs_cot(x + x**2*y, x, 5) == -x**4*y**5 - x**4*y/15 + x**3*y**4 - \
x**3/45 - x**2*y**3 - x**2*y/3 + x*y**2 - x/3 - y + x**(-1)
def test_sin():
R, x, y = ring('x, y', QQ)
assert rs_sin(x, x, 9)/x**5 == \
Rational(-1, 5040)*x**2 + Rational(1, 120) - Rational(1, 6)*x**(-2) + x**(-4)
assert rs_sin(x*y + x**2*y**3, x, 9) == x**8*y**11/12 - \
x**8*y**9/720 + x**7*y**9/12 - x**7*y**7/5040 - x**6*y**9/6 + \
x**6*y**7/24 - x**5*y**7/2 + x**5*y**5/120 - x**4*y**5/2 - \
x**3*y**3/6 + x**2*y**3 + x*y
# Constant term in series
a = symbols('a')
R, x, y = ring('x, y', QQ[sin(a), cos(a), a])
assert rs_sin(x + a, x, 5) == sin(a)*x**4/24 - cos(a)*x**3/6 - \
sin(a)*x**2/2 + cos(a)*x + sin(a)
assert rs_sin(x + x**2*y + a, x, 5) == -sin(a)*x**4*y**2/2 - \
cos(a)*x**4*y/2 + sin(a)*x**4/24 - sin(a)*x**3*y - cos(a)*x**3/6 + \
cos(a)*x**2*y - sin(a)*x**2/2 + cos(a)*x + sin(a)
R, x, y = ring('x, y', EX)
assert rs_sin(x + a, x, 5) == EX(sin(a)/24)*x**4 - EX(cos(a)/6)*x**3 - \
EX(sin(a)/2)*x**2 + EX(cos(a))*x + EX(sin(a))
assert rs_sin(x + x**2*y + a, x, 5) == -EX(sin(a)/2)*x**4*y**2 - \
EX(cos(a)/2)*x**4*y + EX(sin(a)/24)*x**4 - EX(sin(a))*x**3*y - \
EX(cos(a)/6)*x**3 + EX(cos(a))*x**2*y - EX(sin(a)/2)*x**2 + \
EX(cos(a))*x + EX(sin(a))
def test_cos():
R, x, y = ring('x, y', QQ)
assert rs_cos(x, x, 9)/x**5 == \
Rational(1, 40320)*x**3 - Rational(1, 720)*x + Rational(1, 24)*x**(-1) - S.Half*x**(-3) + x**(-5)
assert rs_cos(x*y + x**2*y**3, x, 9) == x**8*y**12/24 - \
x**8*y**10/48 + x**8*y**8/40320 + x**7*y**10/6 - \
x**7*y**8/120 + x**6*y**8/4 - x**6*y**6/720 + x**5*y**6/6 - \
x**4*y**6/2 + x**4*y**4/24 - x**3*y**4 - x**2*y**2/2 + 1
# Constant term in series
a = symbols('a')
R, x, y = ring('x, y', QQ[sin(a), cos(a), a])
assert rs_cos(x + a, x, 5) == cos(a)*x**4/24 + sin(a)*x**3/6 - \
cos(a)*x**2/2 - sin(a)*x + cos(a)
assert rs_cos(x + x**2*y + a, x, 5) == -cos(a)*x**4*y**2/2 + \
sin(a)*x**4*y/2 + cos(a)*x**4/24 - cos(a)*x**3*y + sin(a)*x**3/6 - \
sin(a)*x**2*y - cos(a)*x**2/2 - sin(a)*x + cos(a)
R, x, y = ring('x, y', EX)
assert rs_cos(x + a, x, 5) == EX(cos(a)/24)*x**4 + EX(sin(a)/6)*x**3 - \
EX(cos(a)/2)*x**2 - EX(sin(a))*x + EX(cos(a))
assert rs_cos(x + x**2*y + a, x, 5) == -EX(cos(a)/2)*x**4*y**2 + \
EX(sin(a)/2)*x**4*y + EX(cos(a)/24)*x**4 - EX(cos(a))*x**3*y + \
EX(sin(a)/6)*x**3 - EX(sin(a))*x**2*y - EX(cos(a)/2)*x**2 - \
EX(sin(a))*x + EX(cos(a))
def test_cos_sin():
R, x, y = ring('x, y', QQ)
cos, sin = rs_cos_sin(x, x, 9)
assert cos == rs_cos(x, x, 9)
assert sin == rs_sin(x, x, 9)
cos, sin = rs_cos_sin(x + x*y, x, 5)
assert cos == rs_cos(x + x*y, x, 5)
assert sin == rs_sin(x + x*y, x, 5)
def test_atanh():
R, x, y = ring('x, y', QQ)
assert rs_atanh(x, x, 9)/x**5 == Rational(1, 7)*x**2 + Rational(1, 5) + Rational(1, 3)*x**(-2) + x**(-4)
assert rs_atanh(x*y + x**2*y**3, x, 9) == 2*x**8*y**11 + x**8*y**9 + \
2*x**7*y**9 + x**7*y**7/7 + x**6*y**9/3 + x**6*y**7 + x**5*y**7 + \
x**5*y**5/5 + x**4*y**5 + x**3*y**3/3 + x**2*y**3 + x*y
# Constant term in series
a = symbols('a')
R, x, y = ring('x, y', EX)
assert rs_atanh(x + a, x, 5) == EX((a**3 + a)/(a**8 - 4*a**6 + 6*a**4 - \
4*a**2 + 1))*x**4 - EX((3*a**2 + 1)/(3*a**6 - 9*a**4 + \
9*a**2 - 3))*x**3 + EX(a/(a**4 - 2*a**2 + 1))*x**2 - EX(1/(a**2 - \
1))*x + EX(atanh(a))
assert rs_atanh(x + x**2*y + a, x, 4) == EX(2*a/(a**4 - 2*a**2 + \
1))*x**3*y - EX((3*a**2 + 1)/(3*a**6 - 9*a**4 + 9*a**2 - 3))*x**3 - \
EX(1/(a**2 - 1))*x**2*y + EX(a/(a**4 - 2*a**2 + 1))*x**2 - \
EX(1/(a**2 - 1))*x + EX(atanh(a))
p = x + x**2 + 5
assert rs_atanh(p, x, 10).compose(x, 10) == EX(Rational(-733442653682135, 5079158784) \
+ atanh(5))
def test_sinh():
R, x, y = ring('x, y', QQ)
assert rs_sinh(x, x, 9)/x**5 == Rational(1, 5040)*x**2 + Rational(1, 120) + Rational(1, 6)*x**(-2) + x**(-4)
assert rs_sinh(x*y + x**2*y**3, x, 9) == x**8*y**11/12 + \
x**8*y**9/720 + x**7*y**9/12 + x**7*y**7/5040 + x**6*y**9/6 + \
x**6*y**7/24 + x**5*y**7/2 + x**5*y**5/120 + x**4*y**5/2 + \
x**3*y**3/6 + x**2*y**3 + x*y
def test_cosh():
R, x, y = ring('x, y', QQ)
assert rs_cosh(x, x, 9)/x**5 == Rational(1, 40320)*x**3 + Rational(1, 720)*x + Rational(1, 24)*x**(-1) + \
S.Half*x**(-3) + x**(-5)
assert rs_cosh(x*y + x**2*y**3, x, 9) == x**8*y**12/24 + \
x**8*y**10/48 + x**8*y**8/40320 + x**7*y**10/6 + \
x**7*y**8/120 + x**6*y**8/4 + x**6*y**6/720 + x**5*y**6/6 + \
x**4*y**6/2 + x**4*y**4/24 + x**3*y**4 + x**2*y**2/2 + 1
def test_tanh():
R, x, y = ring('x, y', QQ)
assert rs_tanh(x, x, 9)/x**5 == Rational(-17, 315)*x**2 + Rational(2, 15) - Rational(1, 3)*x**(-2) + x**(-4)
assert rs_tanh(x*y + x**2*y**3, x, 9) == 4*x**8*y**11/3 - \
17*x**8*y**9/45 + 4*x**7*y**9/3 - 17*x**7*y**7/315 - x**6*y**9/3 + \
2*x**6*y**7/3 - x**5*y**7 + 2*x**5*y**5/15 - x**4*y**5 - \
x**3*y**3/3 + x**2*y**3 + x*y
# Constant term in series
a = symbols('a')
R, x, y = ring('x, y', EX)
assert rs_tanh(x + a, x, 5) == EX(tanh(a)**5 - 5*tanh(a)**3/3 +
2*tanh(a)/3)*x**4 + EX(-tanh(a)**4 + 4*tanh(a)**2/3 - QQ(1, 3))*x**3 + \
EX(tanh(a)**3 - tanh(a))*x**2 + EX(-tanh(a)**2 + 1)*x + EX(tanh(a))
p = rs_tanh(x + x**2*y + a, x, 4)
assert (p.compose(x, 10)).compose(y, 5) == EX(-1000*tanh(a)**4 + \
10100*tanh(a)**3 + 2470*tanh(a)**2/3 - 10099*tanh(a) + QQ(530, 3))
def test_RR():
rs_funcs = [rs_sin, rs_cos, rs_tan, rs_cot, rs_atan, rs_tanh]
sympy_funcs = [sin, cos, tan, cot, atan, tanh]
R, x, y = ring('x, y', RR)
a = symbols('a')
for rs_func, sympy_func in zip(rs_funcs, sympy_funcs):
p = rs_func(2 + x, x, 5).compose(x, 5)
q = sympy_func(2 + a).series(a, 0, 5).removeO()
is_close(p.as_expr(), q.subs(a, 5).n())
p = rs_nth_root(2 + x, 5, x, 5).compose(x, 5)
q = ((2 + a)**QQ(1, 5)).series(a, 0, 5).removeO()
is_close(p.as_expr(), q.subs(a, 5).n())
def test_is_regular():
R, x, y = ring('x, y', QQ)
p = 1 + 2*x + x**2 + 3*x**3
assert not rs_is_puiseux(p, x)
p = x + x**QQ(1,5)*y
assert rs_is_puiseux(p, x)
assert not rs_is_puiseux(p, y)
p = x + x**2*y**QQ(1,5)*y
assert not rs_is_puiseux(p, x)
def test_puiseux():
R, x, y = ring('x, y', QQ)
p = x**QQ(2,5) + x**QQ(2,3) + x
r = rs_series_inversion(p, x, 1)
r1 = -x**QQ(14,15) + x**QQ(4,5) - 3*x**QQ(11,15) + x**QQ(2,3) + \
2*x**QQ(7,15) - x**QQ(2,5) - x**QQ(1,5) + x**QQ(2,15) - x**QQ(-2,15) \
+ x**QQ(-2,5)
assert r == r1
r = rs_nth_root(1 + p, 3, x, 1)
assert r == -x**QQ(4,5)/9 + x**QQ(2,3)/3 + x**QQ(2,5)/3 + 1
r = rs_log(1 + p, x, 1)
assert r == -x**QQ(4,5)/2 + x**QQ(2,3) + x**QQ(2,5)
r = rs_LambertW(p, x, 1)
assert r == -x**QQ(4,5) + x**QQ(2,3) + x**QQ(2,5)
p1 = x + x**QQ(1,5)*y
r = rs_exp(p1, x, 1)
assert r == x**QQ(4,5)*y**4/24 + x**QQ(3,5)*y**3/6 + x**QQ(2,5)*y**2/2 + \
x**QQ(1,5)*y + 1
r = rs_atan(p, x, 2)
assert r == -x**QQ(9,5) - x**QQ(26,15) - x**QQ(22,15) - x**QQ(6,5)/3 + \
x + x**QQ(2,3) + x**QQ(2,5)
r = rs_atan(p1, x, 2)
assert r == x**QQ(9,5)*y**9/9 + x**QQ(9,5)*y**4 - x**QQ(7,5)*y**7/7 - \
x**QQ(7,5)*y**2 + x*y**5/5 + x - x**QQ(3,5)*y**3/3 + x**QQ(1,5)*y
r = rs_asin(p, x, 2)
assert r == x**QQ(9,5)/2 + x**QQ(26,15)/2 + x**QQ(22,15)/2 + \
x**QQ(6,5)/6 + x + x**QQ(2,3) + x**QQ(2,5)
r = rs_cot(p, x, 1)
assert r == -x**QQ(14,15) + x**QQ(4,5) - 3*x**QQ(11,15) + \
2*x**QQ(2,3)/3 + 2*x**QQ(7,15) - 4*x**QQ(2,5)/3 - x**QQ(1,5) + \
x**QQ(2,15) - x**QQ(-2,15) + x**QQ(-2,5)
r = rs_cos_sin(p, x, 2)
assert r[0] == x**QQ(28,15)/6 - x**QQ(5,3) + x**QQ(8,5)/24 - x**QQ(7,5) - \
x**QQ(4,3)/2 - x**QQ(16,15) - x**QQ(4,5)/2 + 1
assert r[1] == -x**QQ(9,5)/2 - x**QQ(26,15)/2 - x**QQ(22,15)/2 - \
x**QQ(6,5)/6 + x + x**QQ(2,3) + x**QQ(2,5)
r = rs_atanh(p, x, 2)
assert r == x**QQ(9,5) + x**QQ(26,15) + x**QQ(22,15) + x**QQ(6,5)/3 + x + \
x**QQ(2,3) + x**QQ(2,5)
r = rs_sinh(p, x, 2)
assert r == x**QQ(9,5)/2 + x**QQ(26,15)/2 + x**QQ(22,15)/2 + \
x**QQ(6,5)/6 + x + x**QQ(2,3) + x**QQ(2,5)
r = rs_cosh(p, x, 2)
assert r == x**QQ(28,15)/6 + x**QQ(5,3) + x**QQ(8,5)/24 + x**QQ(7,5) + \
x**QQ(4,3)/2 + x**QQ(16,15) + x**QQ(4,5)/2 + 1
r = rs_tanh(p, x, 2)
assert r == -x**QQ(9,5) - x**QQ(26,15) - x**QQ(22,15) - x**QQ(6,5)/3 + \
x + x**QQ(2,3) + x**QQ(2,5)
def test_puiseux_algebraic(): # https://github.com/sympy/sympy/issues/24395
K = QQ.algebraic_field(sqrt(2))
sqrt2 = K.from_sympy(sqrt(2))
x, y = symbols('x, y')
R, xr, yr = ring([x, y], K)
p = (1+sqrt2)*xr**QQ(1,2) + (1-sqrt2)*yr**QQ(2,3)
assert dict(p) == {(QQ(1,2),QQ(0)):1+sqrt2, (QQ(0),QQ(2,3)):1-sqrt2}
assert p.as_expr() == (1 + sqrt(2))*x**(S(1)/2) + (1 - sqrt(2))*y**(S(2)/3)
def test1():
R, x = ring('x', QQ)
r = rs_sin(x, x, 15)*x**(-5)
assert r == x**8/6227020800 - x**6/39916800 + x**4/362880 - x**2/5040 + \
QQ(1,120) - x**-2/6 + x**-4
p = rs_sin(x, x, 10)
r = rs_nth_root(p, 2, x, 10)
assert r == -67*x**QQ(17,2)/29030400 - x**QQ(13,2)/24192 + \
x**QQ(9,2)/1440 - x**QQ(5,2)/12 + x**QQ(1,2)
p = rs_sin(x, x, 10)
r = rs_nth_root(p, 7, x, 10)
r = rs_pow(r, 5, x, 10)
assert r == -97*x**QQ(61,7)/124467840 - x**QQ(47,7)/16464 + \
11*x**QQ(33,7)/3528 - 5*x**QQ(19,7)/42 + x**QQ(5,7)
r = rs_exp(x**QQ(1,2), x, 10)
assert r == x**QQ(19,2)/121645100408832000 + x**9/6402373705728000 + \
x**QQ(17,2)/355687428096000 + x**8/20922789888000 + \
x**QQ(15,2)/1307674368000 + x**7/87178291200 + \
x**QQ(13,2)/6227020800 + x**6/479001600 + x**QQ(11,2)/39916800 + \
x**5/3628800 + x**QQ(9,2)/362880 + x**4/40320 + x**QQ(7,2)/5040 + \
x**3/720 + x**QQ(5,2)/120 + x**2/24 + x**QQ(3,2)/6 + x/2 + \
x**QQ(1,2) + 1
def test_puiseux2():
R, y = ring('y', QQ)
S, x = ring('x', R)
p = x + x**QQ(1,5)*y
r = rs_atan(p, x, 3)
assert r == (y**13/13 + y**8 + 2*y**3)*x**QQ(13,5) - (y**11/11 + y**6 +
y)*x**QQ(11,5) + (y**9/9 + y**4)*x**QQ(9,5) - (y**7/7 +
y**2)*x**QQ(7,5) + (y**5/5 + 1)*x - y**3*x**QQ(3,5)/3 + y*x**QQ(1,5)
@slow
def test_rs_series():
x, a, b, c = symbols('x, a, b, c')
assert rs_series(a, a, 5).as_expr() == a
assert rs_series(sin(a), a, 5).as_expr() == (sin(a).series(a, 0,
5)).removeO()
assert rs_series(sin(a) + cos(a), a, 5).as_expr() == ((sin(a) +
cos(a)).series(a, 0, 5)).removeO()
assert rs_series(sin(a)*cos(a), a, 5).as_expr() == ((sin(a)*
cos(a)).series(a, 0, 5)).removeO()
p = (sin(a) - a)*(cos(a**2) + a**4/2)
assert expand(rs_series(p, a, 10).as_expr()) == expand(p.series(a, 0,
10).removeO())
p = sin(a**2/2 + a/3) + cos(a/5)*sin(a/2)**3
assert expand(rs_series(p, a, 5).as_expr()) == expand(p.series(a, 0,
5).removeO())
p = sin(x**2 + a)*(cos(x**3 - 1) - a - a**2)
assert expand(rs_series(p, a, 5).as_expr()) == expand(p.series(a, 0,
5).removeO())
p = sin(a**2 - a/3 + 2)**5*exp(a**3 - a/2)
assert expand(rs_series(p, a, 10).as_expr()) == expand(p.series(a, 0,
10).removeO())
p = sin(a + b + c)
assert expand(rs_series(p, a, 5).as_expr()) == expand(p.series(a, 0,
5).removeO())
p = tan(sin(a**2 + 4) + b + c)
assert expand(rs_series(p, a, 6).as_expr()) == expand(p.series(a, 0,
6).removeO())
p = a**QQ(2,5) + a**QQ(2,3) + a
r = rs_series(tan(p), a, 2)
assert r.as_expr() == a**QQ(9,5) + a**QQ(26,15) + a**QQ(22,15) + a**QQ(6,5)/3 + \
a + a**QQ(2,3) + a**QQ(2,5)
r = rs_series(exp(p), a, 1)
assert r.as_expr() == a**QQ(4,5)/2 + a**QQ(2,3) + a**QQ(2,5) + 1
r = rs_series(sin(p), a, 2)
assert r.as_expr() == -a**QQ(9,5)/2 - a**QQ(26,15)/2 - a**QQ(22,15)/2 - \
a**QQ(6,5)/6 + a + a**QQ(2,3) + a**QQ(2,5)
r = rs_series(cos(p), a, 2)
assert r.as_expr() == a**QQ(28,15)/6 - a**QQ(5,3) + a**QQ(8,5)/24 - a**QQ(7,5) - \
a**QQ(4,3)/2 - a**QQ(16,15) - a**QQ(4,5)/2 + 1
assert rs_series(sin(a)/7, a, 5).as_expr() == (sin(a)/7).series(a, 0,
5).removeO()
assert rs_series(log(1 + x), x, 5).as_expr() == -x**4/4 + x**3/3 - \
x**2/2 + x
assert rs_series(log(1 + 4*x), x, 5).as_expr() == -64*x**4 + 64*x**3/3 - \
8*x**2 + 4*x
assert rs_series(log(1 + x + x**2), x, 10).as_expr() == -2*x**9/9 + \
x**8/8 + x**7/7 - x**6/3 + x**5/5 + x**4/4 - 2*x**3/3 + \
x**2/2 + x
assert rs_series(log(1 + x*a**2), x, 7).as_expr() == -x**6*a**12/6 + \
x**5*a**10/5 - x**4*a**8/4 + x**3*a**6/3 - \
x**2*a**4/2 + x*a**2