def test_specfun():
n = Symbol('n')
for f in [besselj, bessely, besseli, besselk]:
assert octave_code(f(n, x)) == f.__name__ + '(n, x)'
for f in (erfc, erfi, erf, erfinv, erfcinv, fresnelc, fresnels, gamma):
assert octave_code(f(x)) == f.__name__ + '(x)'
assert octave_code(hankel1(n, x)) == 'besselh(n, 1, x)'
assert octave_code(hankel2(n, x)) == 'besselh(n, 2, x)'
assert octave_code(airyai(x)) == 'airy(0, x)'
assert octave_code(airyaiprime(x)) == 'airy(1, x)'
assert octave_code(airybi(x)) == 'airy(2, x)'
assert octave_code(airybiprime(x)) == 'airy(3, x)'
assert octave_code(uppergamma(
n, x)) == '(gammainc(x, n, \'upper\').*gamma(n))'
assert octave_code(lowergamma(n, x)) == '(gammainc(x, n).*gamma(n))'
assert octave_code(z**lowergamma(n, x)) == 'z.^(gammainc(x, n).*gamma(n))'
assert octave_code(jn(
n, x)) == 'sqrt(2)*sqrt(pi)*sqrt(1./x).*besselj(n + 1/2, x)/2'
assert octave_code(yn(
n, x)) == 'sqrt(2)*sqrt(pi)*sqrt(1./x).*bessely(n + 1/2, x)/2'
assert octave_code(LambertW(x)) == 'lambertw(x)'
assert octave_code(LambertW(x, n)) == 'lambertw(n, x)'
# Automatic rewrite
assert octave_code(Ei(x)) == 'logint(exp(x))'
assert octave_code(dirichlet_eta(x)) == '(1 - 2.^(1 - x)).*zeta(x)'
assert octave_code(
riemann_xi(x)) == 'pi.^(-x/2).*x.*(x - 1).*gamma(x/2).*zeta(x)/2'
def test_branch_bug():
assert hyperexpand(hyper((Rational(-1, 3), S.Half), (Rational(2, 3), Rational(3, 2)), -z)) == \
-z**S('1/3')*lowergamma(exp_polar(I*pi)/3, z)/5 \
+ sqrt(pi)*erf(sqrt(z))/(5*sqrt(z))
assert hyperexpand(meijerg([Rational(7, 6), 1], [], [Rational(2, 3)], [Rational(1, 6), 0], z)) == \
2*z**S('2/3')*(2*sqrt(pi)*erf(sqrt(z))/sqrt(z) - 2*lowergamma(
Rational(2, 3), z)/z**S('2/3'))*gamma(Rational(2, 3))/gamma(Rational(5, 3))
def test_issue_16536():
if not scipy:
skip("scipy not installed")
a = symbols('a')
f1 = lowergamma(a, x)
F = lambdify((a, x), f1, modules='scipy')
assert abs(lowergamma(1, 3) - F(1, 3)) <= 1e-10
f2 = uppergamma(a, x)
F = lambdify((a, x), f2, modules='scipy')
assert abs(uppergamma(1, 3) - F(1, 3)) <= 1e-10
def test_GammaProcess_symbolic():
t, d, x, y, g, l = symbols('t d x y g l', positive=True)
X = GammaProcess("X", l, g)
raises(NotImplementedError, lambda: X[t])
raises(IndexError, lambda: X(-1))
assert isinstance(X(t), RandomIndexedSymbol)
assert X.state_space == Interval(0, oo)
assert X.distribution(t) == GammaDistribution(g * t, 1 / l)
assert X.joint_distribution(5, X(3)) == JointDistributionHandmade(
Lambda(
(X(5), X(3)),
l**(8 * g) * exp(-l * X(3)) * exp(-l * X(5)) * X(3)**(3 * g - 1) *
X(5)**(5 * g - 1) / (gamma(3 * g) * gamma(5 * g))))
# property of the gamma process at any given timestamp
assert E(X(t)) == g * t / l
assert variance(X(t)).simplify() == g * t / l**2
# Equivalent to E(2*X(1)) + E(X(1)**2) + E(X(1)**3), where E(X(1)) == g/l
assert E(X(t)**2 + X(d)*2 + X(y)**3, Contains(t, Interval.Lopen(0, 1))
& Contains(d, Interval.Lopen(1, 2)) & Contains(y, Interval.Ropen(3, 4))) == \
2*g/l + (g**2 + g)/l**2 + (g**3 + 3*g**2 + 2*g)/l**3
assert P(X(t) > 3, Contains(t, Interval.Lopen(3, 4))).simplify() == \
1 - lowergamma(g, 3*l)/gamma(g) # equivalent to P(X(1)>3)
#test issue 20078
assert (2 * X(t) + 3 * X(t)).simplify() == 5 * X(t)
assert (2 * X(t) - 3 * X(t)).simplify() == -X(t)
assert (2 * (0.25 * X(t))).simplify() == 0.5 * X(t)
assert (2 * X(t) * 0.25 * X(t)).simplify() == 0.5 * X(t)**2
assert (X(t)**2 + X(t)**3).simplify() == (X(t) + 1) * X(t)**2
def test_Mod1_behavior():
from sympy.core.symbol import Symbol
from sympy.simplify.simplify import simplify
n = Symbol('n', integer=True)
# Note: this should not hang.
assert simplify(hyperexpand(meijerg([1], [], [n + 1], [0], z))) == \
lowergamma(n + 1, z)
def test_specfun():
n = Symbol('n')
for f in [besselj, bessely, besseli, besselk]:
assert octave_code(f(n, x)) == f.__name__ + '(n, x)'
for f in (erfc, erfi, erf, erfinv, erfcinv, fresnelc, fresnels, gamma):
assert octave_code(f(x)) == f.__name__ + '(x)'
assert octave_code(hankel1(n, x)) == 'besselh(n, 1, x)'
assert octave_code(hankel2(n, x)) == 'besselh(n, 2, x)'
assert octave_code(airyai(x)) == 'airy(0, x)'
assert octave_code(airyaiprime(x)) == 'airy(1, x)'
assert octave_code(airybi(x)) == 'airy(2, x)'
assert octave_code(airybiprime(x)) == 'airy(3, x)'
assert octave_code(uppergamma(n, x)) == '(gammainc(x, n, \'upper\').*gamma(n))'
assert octave_code(lowergamma(n, x)) == '(gammainc(x, n).*gamma(n))'
assert octave_code(z**lowergamma(n, x)) == 'z.^(gammainc(x, n).*gamma(n))'
assert octave_code(jn(n, x)) == 'sqrt(2)*sqrt(pi)*sqrt(1./x).*besselj(n + 1/2, x)/2'
assert octave_code(yn(n, x)) == 'sqrt(2)*sqrt(pi)*sqrt(1./x).*bessely(n + 1/2, x)/2'
assert octave_code(LambertW(x)) == 'lambertw(x)'
assert octave_code(LambertW(x, n)) == 'lambertw(n, x)'
def test_specfun():
n = Symbol('n')
for f in [besselj, bessely, besseli, besselk]:
assert octave_code(f(n, x)) == f.__name__ + '(n, x)'
for f in (erfc, erfi, erf, erfinv, erfcinv, fresnelc, fresnels, gamma):
assert octave_code(f(x)) == f.__name__ + '(x)'
assert octave_code(hankel1(n, x)) == 'besselh(n, 1, x)'
assert octave_code(hankel2(n, x)) == 'besselh(n, 2, x)'
assert octave_code(airyai(x)) == 'airy(0, x)'
assert octave_code(airyaiprime(x)) == 'airy(1, x)'
assert octave_code(airybi(x)) == 'airy(2, x)'
assert octave_code(airybiprime(x)) == 'airy(3, x)'
assert octave_code(uppergamma(n, x)) == '(gammainc(x, n, \'upper\').*gamma(n))'
assert octave_code(lowergamma(n, x)) == '(gammainc(x, n).*gamma(n))'
assert octave_code(z**lowergamma(n, x)) == 'z.^(gammainc(x, n).*gamma(n))'
assert octave_code(jn(n, x)) == 'sqrt(2)*sqrt(pi)*sqrt(1./x).*besselj(n + 1/2, x)/2'
assert octave_code(yn(n, x)) == 'sqrt(2)*sqrt(pi)*sqrt(1./x).*bessely(n + 1/2, x)/2'
assert octave_code(LambertW(x)) == 'lambertw(x)'
assert octave_code(LambertW(x, n)) == 'lambertw(n, x)'
def test_branch_bug():
from sympy.functions.special.gamma_functions import lowergamma
from sympy.simplify.powsimp import powdenest
# TODO gammasimp cannot prove that the factor is unity
assert powdenest(integrate(erf(x**3), x, meijerg=True).diff(x),
polar=True) == 2 * erf(x**3) * gamma(Rational(
2, 3)) / 3 / gamma(Rational(5, 3))
assert integrate(erf(x**3), x, meijerg=True) == \
2*x*erf(x**3)*gamma(Rational(2, 3))/(3*gamma(Rational(5, 3))) \
- 2*gamma(Rational(2, 3))*lowergamma(Rational(2, 3), x**6)/(3*sqrt(pi)*gamma(Rational(5, 3)))
def test_specfun():
n = Symbol("n")
for f in [besselj, bessely, besseli, besselk]:
assert octave_code(f(n, x)) == f.__name__ + "(n, x)"
for f in (erfc, erfi, erf, erfinv, erfcinv, fresnelc, fresnels, gamma):
assert octave_code(f(x)) == f.__name__ + "(x)"
assert octave_code(hankel1(n, x)) == "besselh(n, 1, x)"
assert octave_code(hankel2(n, x)) == "besselh(n, 2, x)"
assert octave_code(airyai(x)) == "airy(0, x)"
assert octave_code(airyaiprime(x)) == "airy(1, x)"
assert octave_code(airybi(x)) == "airy(2, x)"
assert octave_code(airybiprime(x)) == "airy(3, x)"
assert octave_code(uppergamma(n,
x)) == "(gammainc(x, n, 'upper').*gamma(n))"
assert octave_code(lowergamma(n, x)) == "(gammainc(x, n).*gamma(n))"
assert octave_code(z**lowergamma(n, x)) == "z.^(gammainc(x, n).*gamma(n))"
assert octave_code(jn(
n, x)) == "sqrt(2)*sqrt(pi)*sqrt(1./x).*besselj(n + 1/2, x)/2"
assert octave_code(yn(
n, x)) == "sqrt(2)*sqrt(pi)*sqrt(1./x).*bessely(n + 1/2, x)/2"
assert octave_code(LambertW(x)) == "lambertw(x)"
assert octave_code(LambertW(x, n)) == "lambertw(n, x)"
def test_specfun():
n = Symbol('n')
for f in [besselj, bessely, besseli, besselk]:
assert octave_code(f(n, x)) == f.__name__ + '(n, x)'
assert octave_code(hankel1(n, x)) == 'besselh(n, 1, x)'
assert octave_code(hankel2(n, x)) == 'besselh(n, 2, x)'
assert octave_code(airyai(x)) == 'airy(0, x)'
assert octave_code(airyaiprime(x)) == 'airy(1, x)'
assert octave_code(airybi(x)) == 'airy(2, x)'
assert octave_code(airybiprime(x)) == 'airy(3, x)'
assert octave_code(uppergamma(n, x)) == 'gammainc(x, n, \'upper\')'
assert octave_code(lowergamma(n, x)) == 'gammainc(x, n, \'lower\')'
assert octave_code(jn(n, x)) == 'sqrt(2)*sqrt(pi)*sqrt(1./x).*besselj(n + 1/2, x)/2'
assert octave_code(yn(n, x)) == 'sqrt(2)*sqrt(pi)*sqrt(1./x).*bessely(n + 1/2, x)/2'
def test_specfun():
n = Symbol('n')
for f in [besselj, bessely, besseli, besselk]:
assert octave_code(f(n, x)) == f.__name__ + '(n, x)'
assert octave_code(hankel1(n, x)) == 'besselh(n, 1, x)'
assert octave_code(hankel2(n, x)) == 'besselh(n, 2, x)'
assert octave_code(airyai(x)) == 'airy(0, x)'
assert octave_code(airyaiprime(x)) == 'airy(1, x)'
assert octave_code(airybi(x)) == 'airy(2, x)'
assert octave_code(airybiprime(x)) == 'airy(3, x)'
assert octave_code(uppergamma(n, x)) == 'gammainc(x, n, \'upper\')'
assert octave_code(lowergamma(n, x)) == 'gammainc(x, n, \'lower\')'
assert octave_code(jn(n, x)) == 'sqrt(2)*sqrt(pi)*sqrt(1./x).*besselj(n + 1/2, x)/2'
assert octave_code(yn(n, x)) == 'sqrt(2)*sqrt(pi)*sqrt(1./x).*bessely(n + 1/2, x)/2'
def test_uppergamma():
from sympy.functions.special.error_functions import expint
from sympy.functions.special.hyper import meijerg
assert uppergamma(4, 0) == 6
assert uppergamma(x, y).diff(y) == -y**(x - 1)*exp(-y)
assert td(uppergamma(randcplx(), y), y)
assert uppergamma(x, y).diff(x) == \
uppergamma(x, y)*log(y) + meijerg([], [1, 1], [0, 0, x], [], y)
assert td(uppergamma(x, randcplx()), x)
p = Symbol('p', positive=True)
assert uppergamma(0, p) == -Ei(-p)
assert uppergamma(p, 0) == gamma(p)
assert uppergamma(S.Half, x) == sqrt(pi)*erfc(sqrt(x))
assert not uppergamma(S.Half - 3, x).has(uppergamma)
assert not uppergamma(S.Half + 3, x).has(uppergamma)
assert uppergamma(S.Half, x, evaluate=False).has(uppergamma)
assert tn(uppergamma(S.Half + 3, x, evaluate=False),
uppergamma(S.Half + 3, x), x)
assert tn(uppergamma(S.Half - 3, x, evaluate=False),
uppergamma(S.Half - 3, x), x)
assert unchanged(uppergamma, x, -oo)
assert unchanged(uppergamma, x, 0)
assert tn_branch(-3, uppergamma)
assert tn_branch(-4, uppergamma)
assert tn_branch(Rational(1, 3), uppergamma)
assert tn_branch(pi, uppergamma)
assert uppergamma(3, exp_polar(4*pi*I)*x) == uppergamma(3, x)
assert uppergamma(y, exp_polar(5*pi*I)*x) == \
exp(4*I*pi*y)*uppergamma(y, x*exp_polar(pi*I)) + \
gamma(y)*(1 - exp(4*pi*I*y))
assert uppergamma(-2, exp_polar(5*pi*I)*x) == \
uppergamma(-2, x*exp_polar(I*pi)) - 2*pi*I
assert uppergamma(-2, x) == expint(3, x)/x**2
assert conjugate(uppergamma(x, y)) == uppergamma(conjugate(x), conjugate(y))
assert unchanged(conjugate, uppergamma(x, -oo))
assert uppergamma(x, y).rewrite(expint) == y**x*expint(-x + 1, y)
assert uppergamma(x, y).rewrite(lowergamma) == gamma(x) - lowergamma(x, y)
assert uppergamma(70, 6) == 69035724522603011058660187038367026272747334489677105069435923032634389419656200387949342530805432320*exp(-6)
assert (uppergamma(S(77) / 2, 6) - uppergamma(S(77) / 2, 6, evaluate=False)).evalf() < 1e-16
assert (uppergamma(-S(77) / 2, 6) - uppergamma(-S(77) / 2, 6, evaluate=False)).evalf() < 1e-16
def test_issue_16535_16536():
from sympy.functions.special.gamma_functions import (lowergamma, uppergamma)
a = symbols('a')
expr1 = lowergamma(a, x)
expr2 = uppergamma(a, x)
prntr = SciPyPrinter()
assert prntr.doprint(expr1) == 'scipy.special.gamma(a)*scipy.special.gammainc(a, x)'
assert prntr.doprint(expr2) == 'scipy.special.gamma(a)*scipy.special.gammaincc(a, x)'
prntr = NumPyPrinter()
assert "Not supported" in prntr.doprint(expr1)
assert "Not supported" in prntr.doprint(expr2)
prntr = PythonCodePrinter()
assert "Not supported" in prntr.doprint(expr1)
assert "Not supported" in prntr.doprint(expr2)
def test_hyperexpand_bases():
assert hyperexpand(hyper([2], [a], z)) == \
a + z**(-a + 1)*(-a**2 + 3*a + z*(a - 1) - 2)*exp(z)* \
lowergamma(a - 1, z) - 1
# TODO [a+1, aRational(-1, 2)], [2*a]
assert hyperexpand(hyper([1, 2], [3], z)) == -2/z - 2*log(-z + 1)/z**2
assert hyperexpand(hyper([S.Half, 2], [Rational(3, 2)], z)) == \
-1/(2*z - 2) + atanh(sqrt(z))/sqrt(z)/2
assert hyperexpand(hyper([S.Half, S.Half], [Rational(5, 2)], z)) == \
(-3*z + 3)/4/(z*sqrt(-z + 1)) \
+ (6*z - 3)*asin(sqrt(z))/(4*z**Rational(3, 2))
assert hyperexpand(hyper([1, 2], [Rational(3, 2)], z)) == -1/(2*z - 2) \
- asin(sqrt(z))/(sqrt(z)*(2*z - 2)*sqrt(-z + 1))
assert hyperexpand(hyper([Rational(-1, 2) - 1, 1, 2], [S.Half, 3], z)) == \
sqrt(z)*(z*Rational(6, 7) - Rational(6, 5))*atanh(sqrt(z)) \
+ (-30*z**2 + 32*z - 6)/35/z - 6*log(-z + 1)/(35*z**2)
assert hyperexpand(hyper([1 + S.Half, 1, 1], [2, 2], z)) == \
-4*log(sqrt(-z + 1)/2 + S.Half)/z
# TODO hyperexpand(hyper([a], [2*a + 1], z))
# TODO [S.Half, a], [Rational(3, 2), a+1]
assert hyperexpand(hyper([2], [b, 1], z)) == \
z**(-b/2 + S.Half)*besseli(b - 1, 2*sqrt(z))*gamma(b) \
+ z**(-b/2 + 1)*besseli(b, 2*sqrt(z))*gamma(b)
def _eval_rewrite_as_gamma(self, arg, piecewise=True, **kwargs):
from sympy.functions.elementary.exponential import exp
from sympy.functions.special.gamma_functions import (gamma, lowergamma)
return (S.NegativeOne**(arg + 1) * exp(-I * pi * arg) *
lowergamma(arg + 1, -1) + gamma(arg + 1)) * exp(-1)
def test_meijerint():
from sympy.core.function import expand
from sympy.core.symbol import symbols
from sympy.functions.elementary.complexes import arg
s, t, mu = symbols('s t mu', real=True)
assert integrate(
meijerg([], [], [0], [], s * t) *
meijerg([], [], [mu / 2], [-mu / 2], t**2 / 4),
(t, 0, oo)).is_Piecewise
s = symbols('s', positive=True)
assert integrate(x**s*meijerg([[], []], [[0], []], x), (x, 0, oo)) == \
gamma(s + 1)
assert integrate(x**s * meijerg([[], []], [[0], []], x), (x, 0, oo),
meijerg=True) == gamma(s + 1)
assert isinstance(
integrate(x**s * meijerg([[], []], [[0], []], x), (x, 0, oo),
meijerg=False), Integral)
assert meijerint_indefinite(exp(x), x) == exp(x)
# TODO what simplifications should be done automatically?
# This tests "extra case" for antecedents_1.
a, b = symbols('a b', positive=True)
assert simplify(meijerint_definite(x**a, x, 0, b)[0]) == \
b**(a + 1)/(a + 1)
# This tests various conditions and expansions:
assert meijerint_definite((x + 1)**3 * exp(-x), x, 0, oo) == (16, True)
# Again, how about simplifications?
sigma, mu = symbols('sigma mu', positive=True)
i, c = meijerint_definite(exp(-((x - mu) / (2 * sigma))**2), x, 0, oo)
assert simplify(i) == sqrt(pi) * sigma * (2 - erfc(mu / (2 * sigma)))
assert c == True
i, _ = meijerint_definite(exp(-mu * x) * exp(sigma * x), x, 0, oo)
# TODO it would be nice to test the condition
assert simplify(i) == 1 / (mu - sigma)
# Test substitutions to change limits
assert meijerint_definite(exp(x), x, -oo, 2) == (exp(2), True)
# Note: causes a NaN in _check_antecedents
assert expand(meijerint_definite(exp(x), x, 0, I)[0]) == exp(I) - 1
assert expand(meijerint_definite(exp(-x), x, 0, x)[0]) == \
1 - exp(-exp(I*arg(x))*abs(x))
# Test -oo to oo
assert meijerint_definite(exp(-x**2), x, -oo, oo) == (sqrt(pi), True)
assert meijerint_definite(exp(-abs(x)), x, -oo, oo) == (2, True)
assert meijerint_definite(exp(-(2*x - 3)**2), x, -oo, oo) == \
(sqrt(pi)/2, True)
assert meijerint_definite(exp(-abs(2 * x - 3)), x, -oo, oo) == (1, True)
assert meijerint_definite(
exp(-((x - mu) / sigma)**2 / 2) / sqrt(2 * pi * sigma**2), x, -oo,
oo) == (1, True)
assert meijerint_definite(sinc(x)**2, x, -oo, oo) == (pi, True)
# Test one of the extra conditions for 2 g-functinos
assert meijerint_definite(exp(-x) * sin(x), x, 0, oo) == (S.Half, True)
# Test a bug
def res(n):
return (1 / (1 + x**2)).diff(x, n).subs(x, 1) * (-1)**n
for n in range(6):
assert integrate(exp(-x)*sin(x)*x**n, (x, 0, oo), meijerg=True) == \
res(n)
# This used to test trigexpand... now it is done by linear substitution
assert simplify(integrate(exp(-x) * sin(x + a), (x, 0, oo),
meijerg=True)) == sqrt(2) * sin(a + pi / 4) / 2
# Test the condition 14 from prudnikov.
# (This is besselj*besselj in disguise, to stop the product from being
# recognised in the tables.)
a, b, s = symbols('a b s')
from sympy.functions.elementary.complexes import re
assert meijerint_definite(
meijerg([], [], [a / 2], [-a / 2], x / 4) *
meijerg([], [], [b / 2], [-b / 2], x / 4) * x**(s - 1), x, 0,
oo) == ((4 * 2**(2 * s - 2) * gamma(-2 * s + 1) *
gamma(a / 2 + b / 2 + s) /
(gamma(-a / 2 + b / 2 - s + 1) *
gamma(a / 2 - b / 2 - s + 1) * gamma(a / 2 + b / 2 - s + 1)),
(re(s) < 1) & (re(s) < S(1) / 2) &
(re(a) / 2 + re(b) / 2 + re(s) > 0)))
# test a bug
assert integrate(sin(x**a)*sin(x**b), (x, 0, oo), meijerg=True) == \
Integral(sin(x**a)*sin(x**b), (x, 0, oo))
# test better hyperexpand
assert integrate(exp(-x**2)*log(x), (x, 0, oo), meijerg=True) == \
(sqrt(pi)*polygamma(0, S.Half)/4).expand()
# Test hyperexpand bug.
from sympy.functions.special.gamma_functions import lowergamma
n = symbols('n', integer=True)
assert simplify(integrate(exp(-x)*x**n, x, meijerg=True)) == \
lowergamma(n + 1, x)
# Test a bug with argument 1/x
alpha = symbols('alpha', positive=True)
assert meijerint_definite((2 - x)**alpha*sin(alpha/x), x, 0, 2) == \
(sqrt(pi)*alpha*gamma(alpha + 1)*meijerg(((), (alpha/2 + S.Half,
alpha/2 + 1)), ((0, 0, S.Half), (Rational(-1, 2),)), alpha**2/16)/4, True)
# test a bug related to 3016
a, s = symbols('a s', positive=True)
assert simplify(integrate(x**s*exp(-a*x**2), (x, -oo, oo))) == \
a**(-s/2 - S.Half)*((-1)**s + 1)*gamma(s/2 + S.Half)/2
def test_lowergamma():
from sympy.functions.special.error_functions import expint
from sympy.functions.special.hyper import meijerg
assert lowergamma(x, 0) == 0
assert lowergamma(x, y).diff(y) == y**(x - 1)*exp(-y)
assert td(lowergamma(randcplx(), y), y)
assert td(lowergamma(x, randcplx()), x)
assert lowergamma(x, y).diff(x) == \
gamma(x)*digamma(x) - uppergamma(x, y)*log(y) \
- meijerg([], [1, 1], [0, 0, x], [], y)
assert lowergamma(S.Half, x) == sqrt(pi)*erf(sqrt(x))
assert not lowergamma(S.Half - 3, x).has(lowergamma)
assert not lowergamma(S.Half + 3, x).has(lowergamma)
assert lowergamma(S.Half, x, evaluate=False).has(lowergamma)
assert tn(lowergamma(S.Half + 3, x, evaluate=False),
lowergamma(S.Half + 3, x), x)
assert tn(lowergamma(S.Half - 3, x, evaluate=False),
lowergamma(S.Half - 3, x), x)
assert tn_branch(-3, lowergamma)
assert tn_branch(-4, lowergamma)
assert tn_branch(Rational(1, 3), lowergamma)
assert tn_branch(pi, lowergamma)
assert lowergamma(3, exp_polar(4*pi*I)*x) == lowergamma(3, x)
assert lowergamma(y, exp_polar(5*pi*I)*x) == \
exp(4*I*pi*y)*lowergamma(y, x*exp_polar(pi*I))
assert lowergamma(-2, exp_polar(5*pi*I)*x) == \
lowergamma(-2, x*exp_polar(I*pi)) + 2*pi*I
assert conjugate(lowergamma(x, y)) == lowergamma(conjugate(x), conjugate(y))
assert conjugate(lowergamma(x, 0)) == 0
assert unchanged(conjugate, lowergamma(x, -oo))
assert lowergamma(0, x)._eval_is_meromorphic(x, 0) == False
assert lowergamma(S(1)/3, x)._eval_is_meromorphic(x, 0) == False
assert lowergamma(1, x, evaluate=False)._eval_is_meromorphic(x, 0) == True
assert lowergamma(x, x)._eval_is_meromorphic(x, 0) == False
assert lowergamma(x + 1, x)._eval_is_meromorphic(x, 0) == False
assert lowergamma(1/x, x)._eval_is_meromorphic(x, 0) == False
assert lowergamma(0, x + 1)._eval_is_meromorphic(x, 0) == False
assert lowergamma(S(1)/3, x + 1)._eval_is_meromorphic(x, 0) == True
assert lowergamma(1, x + 1, evaluate=False)._eval_is_meromorphic(x, 0) == True
assert lowergamma(x, x + 1)._eval_is_meromorphic(x, 0) == True
assert lowergamma(x + 1, x + 1)._eval_is_meromorphic(x, 0) == True
assert lowergamma(1/x, x + 1)._eval_is_meromorphic(x, 0) == False
assert lowergamma(0, 1/x)._eval_is_meromorphic(x, 0) == False
assert lowergamma(S(1)/3, 1/x)._eval_is_meromorphic(x, 0) == False
assert lowergamma(1, 1/x, evaluate=False)._eval_is_meromorphic(x, 0) == False
assert lowergamma(x, 1/x)._eval_is_meromorphic(x, 0) == False
assert lowergamma(x + 1, 1/x)._eval_is_meromorphic(x, 0) == False
assert lowergamma(1/x, 1/x)._eval_is_meromorphic(x, 0) == False
assert lowergamma(x, 2).series(x, oo, 3) == \
2**x*(1 + 2/(x + 1))*exp(-2)/x + O(exp(x*log(2))/x**3, (x, oo))
assert lowergamma(
x, y).rewrite(expint) == -y**x*expint(-x + 1, y) + gamma(x)
k = Symbol('k', integer=True)
assert lowergamma(
k, y).rewrite(expint) == -y**k*expint(-k + 1, y) + gamma(k)
k = Symbol('k', integer=True, positive=False)
assert lowergamma(k, y).rewrite(expint) == lowergamma(k, y)
assert lowergamma(x, y).rewrite(uppergamma) == gamma(x) - uppergamma(x, y)
assert lowergamma(70, 6) == factorial(69) - 69035724522603011058660187038367026272747334489677105069435923032634389419656200387949342530805432320 * exp(-6)
assert (lowergamma(S(77) / 2, 6) - lowergamma(S(77) / 2, 6, evaluate=False)).evalf() < 1e-16
assert (lowergamma(-S(77) / 2, 6) - lowergamma(-S(77) / 2, 6, evaluate=False)).evalf() < 1e-16
def test_issue_12173():
#test for issue 12173
exp1 = lambdify((x, y), uppergamma(x, y),"mpmath")(1, 2)
exp2 = lambdify((x, y), lowergamma(x, y),"mpmath")(1, 2)
assert exp1 == uppergamma(1, 2).evalf()
assert exp2 == lowergamma(1, 2).evalf()
def test_sympy__functions__special__gamma_functions__lowergamma():
from sympy.functions.special.gamma_functions import lowergamma
assert _test_args(lowergamma(x, 2))
def chi_square_cdf(x, k):
from sympy.functions.special.gamma_functions import lowergamma
return lowergamma(k / 2, x / 2) / gamma(k / 2)
def test_issue_14450():
assert uppergamma(Rational(3, 8), x).evalf() == uppergamma(Rational(3, 8), x)
assert lowergamma(x, Rational(3, 8)).evalf() == lowergamma(x, Rational(3, 8))
# some values from Wolfram Alpha for comparison
assert abs(uppergamma(Rational(3, 8), 2).evalf() - 0.07105675881) < 1e-9
assert abs(lowergamma(Rational(3, 8), 2).evalf() - 2.2993794256) < 1e-9
def test_issue_12173():
#test for issue 12173
exp1 = lambdify((x, y), uppergamma(x, y), "mpmath")(1, 2)
exp2 = lambdify((x, y), lowergamma(x, y), "mpmath")(1, 2)
assert exp1 == uppergamma(1, 2).evalf()
assert exp2 == lowergamma(1, 2).evalf()
def test_sympy__functions__special__gamma_functions__lowergamma():
from sympy.functions.special.gamma_functions import lowergamma
assert _test_args(lowergamma(x, 2))
