Exemple #1
0
def test_hyper():
    raises(TypeError, lambda: hyper(1, 2, z))

    assert hyper((1, 2), (1,), z) == hyper(Tuple(1, 2), Tuple(1), z)

    h = hyper((1, 2), (3, 4, 5), z)
    assert h.ap == Tuple(1, 2)
    assert h.bq == Tuple(3, 4, 5)
    assert h.argument == z
    assert h.is_commutative is True

    # just a few checks to make sure that all arguments go where they should
    assert tn(hyper(Tuple(), Tuple(), z), exp(z), z)
    assert tn(z*hyper((1, 1), Tuple(2), -z), log(1 + z), z)

    # differentiation
    h = hyper(
        (randcplx(), randcplx(), randcplx()), (randcplx(), randcplx()), z)
    assert td(h, z)

    a1, a2, b1, b2, b3 = symbols('a1:3, b1:4')
    assert hyper((a1, a2), (b1, b2, b3), z).diff(z) == \
        a1*a2/(b1*b2*b3) * hyper((a1 + 1, a2 + 1), (b1 + 1, b2 + 1, b3 + 1), z)

    # differentiation wrt parameters is not supported
    assert hyper([z], [], z).diff(z) == Derivative(hyper([z], [], z), z)

    # hyper is unbranched wrt parameters
    from sympy.functions.elementary.complexes import polar_lift
    assert hyper([polar_lift(z)], [polar_lift(k)], polar_lift(x)) == \
        hyper([z], [k], polar_lift(x))

    # hyper does not automatically evaluate anyway, but the test is to make
    # sure that the evaluate keyword is accepted
    assert hyper((1, 2), (1,), z, evaluate=False).func is hyper
 def t(fac, arg):
     g = meijerg([a], [b], [c], [d], arg) * fac
     subs = {
         a: randcplx() / 10,
         b: randcplx() / 10 + I,
         c: randcplx(),
         d: randcplx()
     }
     integral = meijerint_indefinite(g, x)
     assert integral is not None
     assert verify_numerically(g.subs(subs), integral.diff(x).subs(subs), x)
Exemple #3
0
def test_expand_func():
    # evaluation at 1 of Gauss' hypergeometric function:
    from sympy.abc import a, b, c
    from sympy.core.function import expand_func
    a1, b1, c1 = randcplx(), randcplx(), randcplx() + 5
    assert expand_func(hyper([a, b], [c], 1)) == \
        gamma(c)*gamma(-a - b + c)/(gamma(-a + c)*gamma(-b + c))
    assert abs(expand_func(hyper([a1, b1], [c1], 1)).n()
               - hyper([a1, b1], [c1], 1).n()) < 1e-10

    # hyperexpand wrapper for hyper:
    assert expand_func(hyper([], [], z)) == exp(z)
    assert expand_func(hyper([1, 2, 3], [], z)) == hyper([1, 2, 3], [], z)
    assert expand_func(meijerg([[1, 1], []], [[1], [0]], z)) == log(z + 1)
    assert expand_func(meijerg([[1, 1], []], [[], []], z)) == \
        meijerg([[1, 1], []], [[], []], z)
Exemple #4
0
def test_meijerg_eval():
    from sympy.functions.elementary.exponential import exp_polar
    from sympy.functions.special.bessel import besseli
    from sympy.abc import l
    a = randcplx()
    arg = x*exp_polar(k*pi*I)
    expr1 = pi*meijerg([[], [(a + 1)/2]], [[a/2], [-a/2, (a + 1)/2]], arg**2/4)
    expr2 = besseli(a, arg)

    # Test that the two expressions agree for all arguments.
    for x_ in [0.5, 1.5]:
        for k_ in [0.0, 0.1, 0.3, 0.5, 0.8, 1, 5.751, 15.3]:
            assert abs((expr1 - expr2).n(subs={x: x_, k: k_})) < 1e-10
            assert abs((expr1 - expr2).n(subs={x: x_, k: -k_})) < 1e-10

    # Test continuity independently
    eps = 1e-13
    expr2 = expr1.subs(k, l)
    for x_ in [0.5, 1.5]:
        for k_ in [0.5, Rational(1, 3), 0.25, 0.75, Rational(2, 3), 1.0, 1.5]:
            assert abs((expr1 - expr2).n(
                       subs={x: x_, k: k_ + eps, l: k_ - eps})) < 1e-10
            assert abs((expr1 - expr2).n(
                       subs={x: x_, k: -k_ + eps, l: -k_ - eps})) < 1e-10

    expr = (meijerg(((0.5,), ()), ((0.5, 0, 0.5), ()), exp_polar(-I*pi)/4)
            + meijerg(((0.5,), ()), ((0.5, 0, 0.5), ()), exp_polar(I*pi)/4)) \
        /(2*sqrt(pi))
    assert (expr - pi/exp(1)).n(chop=True) == 0
Exemple #5
0
def test_conjugate():
    n = Symbol('n')
    z = Symbol('z', extended_real=False)
    x = Symbol('x', extended_real=True)
    y = Symbol('y', positive=True)
    t = Symbol('t', negative=True)

    for f in [besseli, besselj, besselk, bessely, hankel1, hankel2]:
        assert f(n, -1).conjugate() != f(conjugate(n), -1)
        assert f(n, x).conjugate() != f(conjugate(n), x)
        assert f(n, t).conjugate() != f(conjugate(n), t)

    rz = randcplx(b=0.5)

    for f in [besseli, besselj, besselk, bessely]:
        assert f(n, 1 + I).conjugate() == f(conjugate(n), 1 - I)
        assert f(n, 0).conjugate() == f(conjugate(n), 0)
        assert f(n, 1).conjugate() == f(conjugate(n), 1)
        assert f(n, z).conjugate() == f(conjugate(n), conjugate(z))
        assert f(n, y).conjugate() == f(conjugate(n), y)
        assert tn(f(n, rz).conjugate(), f(conjugate(n), conjugate(rz)))

    assert hankel1(n, 1 + I).conjugate() == hankel2(conjugate(n), 1 - I)
    assert hankel1(n, 0).conjugate() == hankel2(conjugate(n), 0)
    assert hankel1(n, 1).conjugate() == hankel2(conjugate(n), 1)
    assert hankel1(n, y).conjugate() == hankel2(conjugate(n), y)
    assert hankel1(n, z).conjugate() == hankel2(conjugate(n), conjugate(z))
    assert tn(hankel1(n, rz).conjugate(), hankel2(conjugate(n), conjugate(rz)))

    assert hankel2(n, 1 + I).conjugate() == hankel1(conjugate(n), 1 - I)
    assert hankel2(n, 0).conjugate() == hankel1(conjugate(n), 0)
    assert hankel2(n, 1).conjugate() == hankel1(conjugate(n), 1)
    assert hankel2(n, y).conjugate() == hankel1(conjugate(n), y)
    assert hankel2(n, z).conjugate() == hankel1(conjugate(n), conjugate(z))
    assert tn(hankel2(n, rz).conjugate(), hankel1(conjugate(n), conjugate(rz)))
Exemple #6
0
def test_slow_expand():
    def check(eq, ans):
        return tn(eq, ans) and eq == ans

    rn = randcplx(a=1, b=0, d=0, c=2)

    for besselx in [besselj, bessely, besseli, besselk]:
        ri = S(2*randint(-11, 10) + 1) / 2  # half integer in [-21/2, 21/2]
        assert tn(besselsimp(besselx(ri, z)), besselx(ri, z))

    assert check(expand_func(besseli(rn, x)),
                 besseli(rn - 2, x) - 2*(rn - 1)*besseli(rn - 1, x)/x)
    assert check(expand_func(besseli(-rn, x)),
                 besseli(-rn + 2, x) + 2*(-rn + 1)*besseli(-rn + 1, x)/x)

    assert check(expand_func(besselj(rn, x)),
                 -besselj(rn - 2, x) + 2*(rn - 1)*besselj(rn - 1, x)/x)
    assert check(expand_func(besselj(-rn, x)),
                 -besselj(-rn + 2, x) + 2*(-rn + 1)*besselj(-rn + 1, x)/x)

    assert check(expand_func(besselk(rn, x)),
                 besselk(rn - 2, x) + 2*(rn - 1)*besselk(rn - 1, x)/x)
    assert check(expand_func(besselk(-rn, x)),
                 besselk(-rn + 2, x) - 2*(-rn + 1)*besselk(-rn + 1, x)/x)

    assert check(expand_func(bessely(rn, x)),
                 -bessely(rn - 2, x) + 2*(rn - 1)*bessely(rn - 1, x)/x)
    assert check(expand_func(bessely(-rn, x)),
                 -bessely(-rn + 2, x) + 2*(-rn + 1)*bessely(-rn + 1, x)/x)
def test_F():
    assert F(z, 0) == z
    assert F(0, m) == 0
    assert F(pi*i/2, m) == i*K(m)
    assert F(z, oo) == 0
    assert F(z, -oo) == 0

    assert F(-z, m) == -F(z, m)

    assert F(z, m).diff(z) == 1/sqrt(1 - m*sin(z)**2)
    assert F(z, m).diff(m) == E(z, m)/(2*m*(1 - m)) - F(z, m)/(2*m) - \
        sin(2*z)/(4*(1 - m)*sqrt(1 - m*sin(z)**2))
    r = randcplx()
    assert td(F(z, r), z)
    assert td(F(r, m), m)

    mi = Symbol('m', real=False)
    assert F(z, mi).conjugate() == F(z.conjugate(), mi.conjugate())
    mr = Symbol('m', negative=True)
    assert F(z, mr).conjugate() == F(z.conjugate(), mr)

    assert F(z, m).series(z) == \
        z + z**5*(3*m**2/40 - m/30) + m*z**3/6 + O(z**6)

    assert F(z, m).rewrite(Integral).dummy_eq(
        Integral(1/sqrt(1 - m*sin(t)**2), (t, 0, z)))
Exemple #8
0
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
Exemple #9
0
def test_rewrite():
    assert besselj(n, z).rewrite(jn) == sqrt(2*z/pi)*jn(n - S.Half, z)
    assert bessely(n, z).rewrite(yn) == sqrt(2*z/pi)*yn(n - S.Half, z)
    assert besseli(n, z).rewrite(besselj) == \
        exp(-I*n*pi/2)*besselj(n, polar_lift(I)*z)
    assert besselj(n, z).rewrite(besseli) == \
        exp(I*n*pi/2)*besseli(n, polar_lift(-I)*z)

    nu = randcplx()

    assert tn(besselj(nu, z), besselj(nu, z).rewrite(besseli), z)
    assert tn(besselj(nu, z), besselj(nu, z).rewrite(bessely), z)

    assert tn(besseli(nu, z), besseli(nu, z).rewrite(besselj), z)
    assert tn(besseli(nu, z), besseli(nu, z).rewrite(bessely), z)

    assert tn(bessely(nu, z), bessely(nu, z).rewrite(besselj), z)
    assert tn(bessely(nu, z), bessely(nu, z).rewrite(besseli), z)

    assert tn(besselk(nu, z), besselk(nu, z).rewrite(besselj), z)
    assert tn(besselk(nu, z), besselk(nu, z).rewrite(besseli), z)
    assert tn(besselk(nu, z), besselk(nu, z).rewrite(bessely), z)

    # check that a rewrite was triggered, when the order is set to a generic
    # symbol 'nu'
    assert yn(nu, z) != yn(nu, z).rewrite(jn)
    assert hn1(nu, z) != hn1(nu, z).rewrite(jn)
    assert hn2(nu, z) != hn2(nu, z).rewrite(jn)
    assert jn(nu, z) != jn(nu, z).rewrite(yn)
    assert hn1(nu, z) != hn1(nu, z).rewrite(yn)
    assert hn2(nu, z) != hn2(nu, z).rewrite(yn)

    # rewriting spherical bessel functions (SBFs) w.r.t. besselj, bessely is
    # not allowed if a generic symbol 'nu' is used as the order of the SBFs
    # to avoid inconsistencies (the order of bessel[jy] is allowed to be
    # complex-valued, whereas SBFs are defined only for integer orders)
    order = nu
    for f in (besselj, bessely):
        assert hn1(order, z) == hn1(order, z).rewrite(f)
        assert hn2(order, z) == hn2(order, z).rewrite(f)

    assert jn(order, z).rewrite(besselj) == sqrt(2)*sqrt(pi)*sqrt(1/z)*besselj(order + S.Half, z)/2
    assert jn(order, z).rewrite(bessely) == (-1)**nu*sqrt(2)*sqrt(pi)*sqrt(1/z)*bessely(-order - S.Half, z)/2

    # for integral orders rewriting SBFs w.r.t bessel[jy] is allowed
    N = Symbol('n', integer=True)
    ri = randint(-11, 10)
    for order in (ri, N):
        for f in (besselj, bessely):
            assert yn(order, z) != yn(order, z).rewrite(f)
            assert jn(order, z) != jn(order, z).rewrite(f)
            assert hn1(order, z) != hn1(order, z).rewrite(f)
            assert hn2(order, z) != hn2(order, z).rewrite(f)

    for func, refunc in product((yn, jn, hn1, hn2),
                                (jn, yn, besselj, bessely)):
        assert tn(func(ri, z), func(ri, z).rewrite(refunc), z)
def test_derivatives():
    from sympy.core.function import Derivative
    assert zeta(x, a).diff(x) == Derivative(zeta(x, a), x)
    assert zeta(x, a).diff(a) == -x*zeta(x + 1, a)
    assert lerchphi(
        z, s, a).diff(z) == (lerchphi(z, s - 1, a) - a*lerchphi(z, s, a))/z
    assert lerchphi(z, s, a).diff(a) == -s*lerchphi(z, s + 1, a)
    assert polylog(s, z).diff(z) == polylog(s - 1, z)/z

    b = randcplx()
    c = randcplx()
    assert td(zeta(b, x), x)
    assert td(polylog(b, z), z)
    assert td(lerchphi(c, b, x), x)
    assert td(lerchphi(x, b, c), x)
    raises(ArgumentIndexError, lambda: lerchphi(c, b, x).fdiff(2))
    raises(ArgumentIndexError, lambda: lerchphi(c, b, x).fdiff(4))
    raises(ArgumentIndexError, lambda: polylog(b, z).fdiff(1))
    raises(ArgumentIndexError, lambda: polylog(b, z).fdiff(3))
def myexpand(func, target):
    expanded = expand_func(func)
    if target is not None:
        return expanded == target
    if expanded == func:  # it didn't expand
        return False

    # check to see that the expanded and original evaluate to the same value
    subs = {}
    for a in func.free_symbols:
        subs[a] = randcplx()
    return abs(func.subs(subs).n()
               - expanded.replace(exp_polar, exp).subs(subs).n()) < 1e-10
Exemple #12
0
def test_inflate():
    subs = {
        a: randcplx() / 10,
        b: randcplx() / 10 + I,
        c: randcplx(),
        d: randcplx(),
        y: randcplx() / 10
    }

    def t(a, b, arg, n):
        from sympy.core.mul import Mul
        m1 = meijerg(a, b, arg)
        m2 = Mul(*_inflate_g(m1, n))
        # NOTE: (the random number)**9 must still be on the principal sheet.
        # Thus make b&d small to create random numbers of small imaginary part.
        return verify_numerically(m1.subs(subs),
                                  m2.subs(subs),
                                  x,
                                  b=0.1,
                                  d=-0.1)

    assert t([[a], [b]], [[c], [d]], x, 3)
    assert t([[a, y], [b]], [[c], [d]], x, 3)
    assert t([[a], [b]], [[c, y], [d]], 2 * x**3, 3)
Exemple #13
0
def test_meijerg_derivative():
    assert meijerg([], [1, 1], [0, 0, x], [], z).diff(x) == \
        log(z)*meijerg([], [1, 1], [0, 0, x], [], z) \
        + 2*meijerg([], [1, 1, 1], [0, 0, x, 0], [], z)

    y = randcplx()
    a = 5  # mpmath chokes with non-real numbers, and Mod1 with floats
    assert td(meijerg([x], [], [], [], y), x)
    assert td(meijerg([x**2], [], [], [], y), x)
    assert td(meijerg([], [x], [], [], y), x)
    assert td(meijerg([], [], [x], [], y), x)
    assert td(meijerg([], [], [], [x], y), x)
    assert td(meijerg([x], [a], [a + 1], [], y), x)
    assert td(meijerg([x], [a + 1], [a], [], y), x)
    assert td(meijerg([x, a], [], [], [a + 1], y), x)
    assert td(meijerg([x, a + 1], [], [], [a], y), x)
    b = Rational(3, 2)
    assert td(meijerg([a + 2], [b], [b - 3, x], [a], y), x)
def test_E():
    assert E(z, 0) == z
    assert E(0, m) == 0
    assert E(i*pi/2, m) == i*E(m)
    assert E(z, oo) is zoo
    assert E(z, -oo) is zoo
    assert E(0) == pi/2
    assert E(1) == 1
    assert E(oo) == I*oo
    assert E(-oo) is oo
    assert E(zoo) is zoo

    assert E(-z, m) == -E(z, m)

    assert E(z, m).diff(z) == sqrt(1 - m*sin(z)**2)
    assert E(z, m).diff(m) == (E(z, m) - F(z, m))/(2*m)
    assert E(z).diff(z) == (E(z) - K(z))/(2*z)
    r = randcplx()
    assert td(E(r, m), m)
    assert td(E(z, r), z)
    assert td(E(z), z)

    mi = Symbol('m', real=False)
    assert E(z, mi).conjugate() == E(z.conjugate(), mi.conjugate())
    assert E(mi).conjugate() == E(mi.conjugate())
    mr = Symbol('m', negative=True)
    assert E(z, mr).conjugate() == E(z.conjugate(), mr)
    assert E(mr).conjugate() == E(mr)

    assert E(z).rewrite(hyper) == (pi/2)*hyper((Rational(-1, 2), S.Half), (S.One,), z)
    assert tn(E(z), (pi/2)*hyper((Rational(-1, 2), S.Half), (S.One,), z))
    assert E(z).rewrite(meijerg) == \
        -meijerg(((S.Half, Rational(3, 2)), []), ((S.Zero,), (S.Zero,)), -z)/4
    assert tn(E(z), -meijerg(((S.Half, Rational(3, 2)), []), ((S.Zero,), (S.Zero,)), -z)/4)

    assert E(z, m).series(z) == \
        z + z**5*(-m**2/40 + m/30) - m*z**3/6 + O(z**6)
    assert E(z).series(z) == pi/2 - pi*z/8 - 3*pi*z**2/128 - \
        5*pi*z**3/512 - 175*pi*z**4/32768 - 441*pi*z**5/131072 + O(z**6)

    assert E(z, m).rewrite(Integral).dummy_eq(
        Integral(sqrt(1 - m*sin(t)**2), (t, 0, z)))
    assert E(m).rewrite(Integral).dummy_eq(
        Integral(sqrt(1 - m*sin(t)**2), (t, 0, pi/2)))
Exemple #15
0
def test_meijer():
    raises(TypeError, lambda: meijerg(1, z))
    raises(TypeError, lambda: meijerg(((1,), (2,)), (3,), (4,), z))

    assert meijerg(((1, 2), (3,)), ((4,), (5,)), z) == \
        meijerg(Tuple(1, 2), Tuple(3), Tuple(4), Tuple(5), z)

    g = meijerg((1, 2), (3, 4, 5), (6, 7, 8, 9), (10, 11, 12, 13, 14), z)
    assert g.an == Tuple(1, 2)
    assert g.ap == Tuple(1, 2, 3, 4, 5)
    assert g.aother == Tuple(3, 4, 5)
    assert g.bm == Tuple(6, 7, 8, 9)
    assert g.bq == Tuple(6, 7, 8, 9, 10, 11, 12, 13, 14)
    assert g.bother == Tuple(10, 11, 12, 13, 14)
    assert g.argument == z
    assert g.nu == 75
    assert g.delta == -1
    assert g.is_commutative is True
    assert g.is_number is False
    #issue 13071
    assert meijerg([[],[]], [[S.Half],[0]], 1).is_number is True

    assert meijerg([1, 2], [3], [4], [5], z).delta == S.Half

    # just a few checks to make sure that all arguments go where they should
    assert tn(meijerg(Tuple(), Tuple(), Tuple(0), Tuple(), -z), exp(z), z)
    assert tn(sqrt(pi)*meijerg(Tuple(), Tuple(),
                               Tuple(0), Tuple(S.Half), z**2/4), cos(z), z)
    assert tn(meijerg(Tuple(1, 1), Tuple(), Tuple(1), Tuple(0), z),
              log(1 + z), z)

    # test exceptions
    raises(ValueError, lambda: meijerg(((3, 1), (2,)), ((oo,), (2, 0)), x))
    raises(ValueError, lambda: meijerg(((3, 1), (2,)), ((1,), (2, 0)), x))

    # differentiation
    g = meijerg((randcplx(),), (randcplx() + 2*I,), Tuple(),
                (randcplx(), randcplx()), z)
    assert td(g, z)

    g = meijerg(Tuple(), (randcplx(),), Tuple(),
                (randcplx(), randcplx()), z)
    assert td(g, z)

    g = meijerg(Tuple(), Tuple(), Tuple(randcplx()),
                Tuple(randcplx(), randcplx()), z)
    assert td(g, z)

    a1, a2, b1, b2, c1, c2, d1, d2 = symbols('a1:3, b1:3, c1:3, d1:3')
    assert meijerg((a1, a2), (b1, b2), (c1, c2), (d1, d2), z).diff(z) == \
        (meijerg((a1 - 1, a2), (b1, b2), (c1, c2), (d1, d2), z)
         + (a1 - 1)*meijerg((a1, a2), (b1, b2), (c1, c2), (d1, d2), z))/z

    assert meijerg([z, z], [], [], [], z).diff(z) == \
        Derivative(meijerg([z, z], [], [], [], z), z)

    # meijerg is unbranched wrt parameters
    from sympy.functions.elementary.complexes import polar_lift as pl
    assert meijerg([pl(a1)], [pl(a2)], [pl(b1)], [pl(b2)], pl(z)) == \
        meijerg([a1], [a2], [b1], [b2], pl(z))

    # integrand
    from sympy.abc import a, b, c, d, s
    assert meijerg([a], [b], [c], [d], z).integrand(s) == \
        z**s*gamma(c - s)*gamma(-a + s + 1)/(gamma(b - s)*gamma(-d + s + 1))
Exemple #16
0
def test_bessel_rand():
    for f in [besselj, bessely, besseli, besselk, hankel1, hankel2]:
        assert td(f(randcplx(), z), z)

    for f in [jn, yn, hn1, hn2]:
        assert td(f(randint(-10, 10), z), z)
Exemple #17
0
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