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Python sympy.besselj函数代码示例

原作者: [db:作者] 来自: [db:来源] 收藏 邀请

本文整理汇总了Python中sympy.besselj函数的典型用法代码示例。如果您正苦于以下问题:Python besselj函数的具体用法?Python besselj怎么用?Python besselj使用的例子?那么恭喜您, 这里精选的函数代码示例或许可以为您提供帮助。



在下文中一共展示了besselj函数的20个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于我们的系统推荐出更棒的Python代码示例。

示例1: test_airyai

def test_airyai():
    z = Symbol('z', real=False)
    t = Symbol('t', negative=True)
    p = Symbol('p', positive=True)

    assert isinstance(airyai(z), airyai)

    assert airyai(0) == 3**(S(1)/3)/(3*gamma(S(2)/3))
    assert airyai(oo) == 0
    assert airyai(-oo) == 0

    assert diff(airyai(z), z) == airyaiprime(z)

    assert series(airyai(z), z, 0, 3) == (
        3**(S(5)/6)*gamma(S(1)/3)/(6*pi) - 3**(S(1)/6)*z*gamma(S(2)/3)/(2*pi) + O(z**3))

    assert airyai(z).rewrite(hyper) == (
        -3**(S(2)/3)*z*hyper((), (S(4)/3,), z**S(3)/9)/(3*gamma(S(1)/3)) +
         3**(S(1)/3)*hyper((), (S(2)/3,), z**S(3)/9)/(3*gamma(S(2)/3)))

    assert isinstance(airyai(z).rewrite(besselj), airyai)
    assert airyai(t).rewrite(besselj) == (
        sqrt(-t)*(besselj(-S(1)/3, 2*(-t)**(S(3)/2)/3) +
                  besselj(S(1)/3, 2*(-t)**(S(3)/2)/3))/3)
    assert airyai(z).rewrite(besseli) == (
        -z*besseli(S(1)/3, 2*z**(S(3)/2)/3)/(3*(z**(S(3)/2))**(S(1)/3)) +
         (z**(S(3)/2))**(S(1)/3)*besseli(-S(1)/3, 2*z**(S(3)/2)/3)/3)
    assert airyai(p).rewrite(besseli) == (
        sqrt(p)*(besseli(-S(1)/3, 2*p**(S(3)/2)/3) -
                 besseli(S(1)/3, 2*p**(S(3)/2)/3))/3)

    assert expand_func(airyai(2*(3*z**5)**(S(1)/3))) == (
        -sqrt(3)*(-1 + (z**5)**(S(1)/3)/z**(S(5)/3))*airybi(2*3**(S(1)/3)*z**(S(5)/3))/6 +
         (1 + (z**5)**(S(1)/3)/z**(S(5)/3))*airyai(2*3**(S(1)/3)*z**(S(5)/3))/2)
开发者ID:KonstantinTogoi,项目名称:sympy,代码行数:34,代码来源:test_bessel.py


示例2: test_from_sympy

def test_from_sympy():
    x = symbols("x")
    R, Dx = DifferentialOperators(QQ.old_poly_ring(x), "Dx")
    p = from_sympy((sin(x) / x) ** 2)
    q = HolonomicFunction(
        8 * x + (4 * x ** 2 + 6) * Dx + 6 * x * Dx ** 2 + x ** 2 * Dx ** 3,
        x,
        1,
        [sin(1) ** 2, -2 * sin(1) ** 2 + 2 * sin(1) * cos(1), -8 * sin(1) * cos(1) + 2 * cos(1) ** 2 + 4 * sin(1) ** 2],
    )
    assert p == q
    p = from_sympy(1 / (1 + x ** 2) ** 2)
    q = HolonomicFunction(4 * x + (x ** 2 + 1) * Dx, x, 0, 1)
    assert p == q
    p = from_sympy(exp(x) * sin(x) + x * log(1 + x))
    q = HolonomicFunction(
        (4 * x ** 3 + 20 * x ** 2 + 40 * x + 36)
        + (-4 * x ** 4 - 20 * x ** 3 - 40 * x ** 2 - 36 * x) * Dx
        + (4 * x ** 5 + 12 * x ** 4 + 14 * x ** 3 + 16 * x ** 2 + 20 * x - 8) * Dx ** 2
        + (-4 * x ** 5 - 10 * x ** 4 - 4 * x ** 3 + 4 * x ** 2 - 2 * x + 8) * Dx ** 3
        + (2 * x ** 5 + 4 * x ** 4 - 2 * x ** 3 - 7 * x ** 2 + 2 * x + 5) * Dx ** 4,
        x,
        0,
        [0, 1, 4, -1],
    )
    assert p == q
    p = from_sympy(x * exp(x) + cos(x) + 1)
    q = HolonomicFunction(
        (-x - 3) * Dx + (x + 2) * Dx ** 2 + (-x - 3) * Dx ** 3 + (x + 2) * Dx ** 4, x, 0, [2, 1, 1, 3]
    )
    assert p == q
    assert (x * exp(x) + cos(x) + 1).series(n=10) == p.series(n=10)
    p = from_sympy(log(1 + x) ** 2 + 1)
    q = HolonomicFunction(Dx + (3 * x + 3) * Dx ** 2 + (x ** 2 + 2 * x + 1) * Dx ** 3, x, 0, [1, 0, 2])
    assert p == q
    p = from_sympy(erf(x) ** 2 + x)
    q = HolonomicFunction(
        (32 * x ** 4 - 8 * x ** 2 + 8) * Dx ** 2 + (24 * x ** 3 - 2 * x) * Dx ** 3 + (4 * x ** 2 + 1) * Dx ** 4,
        x,
        0,
        [0, 1, 8 / pi, 0],
    )
    assert p == q
    p = from_sympy(cosh(x) * x)
    q = HolonomicFunction((-x ** 2 + 2) - 2 * x * Dx + x ** 2 * Dx ** 2, x, 0, [0, 1])
    assert p == q
    p = from_sympy(besselj(2, x))
    q = HolonomicFunction((x ** 2 - 4) + x * Dx + x ** 2 * Dx ** 2, x, 0, [0, 0])
    assert p == q
    p = from_sympy(besselj(0, x) + exp(x))
    q = HolonomicFunction(
        (-2 * x ** 2 - x + 1)
        + (2 * x ** 2 - x - 3) * Dx
        + (-2 * x ** 2 + x + 2) * Dx ** 2
        + (2 * x ** 2 + x) * Dx ** 3,
        x,
        0,
        [2, 1, 1 / 2],
    )
    assert p == q
开发者ID:rwong,项目名称:sympy,代码行数:60,代码来源:test_holonomic.py


示例3: test_airybiprime

def test_airybiprime():
    z = Symbol('z', real=False)
    t = Symbol('t', negative=True)
    p = Symbol('p', positive=True)

    assert isinstance(airybiprime(z), airybiprime)

    assert airybiprime(0) == 3**(S(1)/6)/gamma(S(1)/3)
    assert airybiprime(oo) == oo
    assert airybiprime(-oo) == 0

    assert diff(airybiprime(z), z) == z*airybi(z)

    assert series(airybiprime(z), z, 0, 3) == (
        3**(S(1)/6)/gamma(S(1)/3) + 3**(S(5)/6)*z**2/(6*gamma(S(2)/3)) + O(z**3))

    assert airybiprime(z).rewrite(hyper) == (
        3**(S(5)/6)*z**2*hyper((), (S(5)/3,), z**S(3)/9)/(6*gamma(S(2)/3)) +
        3**(S(1)/6)*hyper((), (S(1)/3,), z**S(3)/9)/gamma(S(1)/3))

    assert isinstance(airybiprime(z).rewrite(besselj), airybiprime)
    assert airyai(t).rewrite(besselj) == (
        sqrt(-t)*(besselj(-S(1)/3, 2*(-t)**(S(3)/2)/3) +
                  besselj(S(1)/3, 2*(-t)**(S(3)/2)/3))/3)
    assert airybiprime(z).rewrite(besseli) == (
        sqrt(3)*(z**2*besseli(S(2)/3, 2*z**(S(3)/2)/3)/(z**(S(3)/2))**(S(2)/3) +
                 (z**(S(3)/2))**(S(2)/3)*besseli(-S(2)/3, 2*z**(S(3)/2)/3))/3)
    assert airybiprime(p).rewrite(besseli) == (
        sqrt(3)*p*(besseli(-S(2)/3, 2*p**(S(3)/2)/3) + besseli(S(2)/3, 2*p**(S(3)/2)/3))/3)

    assert expand_func(airybiprime(2*(3*z**5)**(S(1)/3))) == (
        sqrt(3)*(z**(S(5)/3)/(z**5)**(S(1)/3) - 1)*airyaiprime(2*3**(S(1)/3)*z**(S(5)/3))/2 +
        (z**(S(5)/3)/(z**5)**(S(1)/3) + 1)*airybiprime(2*3**(S(1)/3)*z**(S(5)/3))/2)
开发者ID:KonstantinTogoi,项目名称:sympy,代码行数:33,代码来源:test_bessel.py


示例4: test_to_hyper

def test_to_hyper():
    x = symbols('x')
    R, Dx = DifferentialOperators(QQ.old_poly_ring(x), 'Dx')
    p = HolonomicFunction(Dx - 2, x, 0, [3]).to_hyper()
    q = 3 * hyper([], [], 2*x)
    assert p == q
    p = hyperexpand(HolonomicFunction((1 + x) * Dx - 3, x, 0, [2]).to_hyper()).expand()
    q = 2*x**3 + 6*x**2 + 6*x + 2
    assert p == q
    p = HolonomicFunction((1 + x)*Dx**2 + Dx, x, 0, [0, 1]).to_hyper()
    q = -x**2*hyper((2, 2, 1), (2, 3), -x)/2 + x
    assert p == q
    p = HolonomicFunction(2*x*Dx + Dx**2, x, 0, [0, 2/sqrt(pi)]).to_hyper()
    q = 2*x*hyper((1/2,), (3/2,), -x**2)/sqrt(pi)
    assert p == q
    p = hyperexpand(HolonomicFunction(2*x*Dx + Dx**2, x, 0, [1, -2/sqrt(pi)]).to_hyper())
    q = erfc(x)
    assert p.rewrite(erfc) == q
    p =  hyperexpand(HolonomicFunction((x**2 - 1) + x*Dx + x**2*Dx**2,
        x, 0, [0, S(1)/2]).to_hyper())
    q = besselj(1, x)
    assert p == q
    p = hyperexpand(HolonomicFunction(x*Dx**2 + Dx + x, x, 0, [1, 0]).to_hyper())
    q = besselj(0, x)
    assert p == q
开发者ID:ashutoshsaboo,项目名称:sympy,代码行数:25,代码来源:test_holonomic.py


示例5: test_diff

def test_diff():
    assert besselj(n, z).diff(z) == besselj(n - 1, z)/2 - besselj(n + 1, z)/2
    assert bessely(n, z).diff(z) == bessely(n - 1, z)/2 - bessely(n + 1, z)/2
    assert besseli(n, z).diff(z) == besseli(n - 1, z)/2 + besseli(n + 1, z)/2
    assert besselk(n, z).diff(z) == -besselk(n - 1, z)/2 - besselk(n + 1, z)/2
    assert hankel1(n, z).diff(z) == hankel1(n - 1, z)/2 - hankel1(n + 1, z)/2
    assert hankel2(n, z).diff(z) == hankel2(n - 1, z)/2 - hankel2(n + 1, z)/2
开发者ID:Abhityagi16,项目名称:sympy,代码行数:7,代码来源:test_bessel.py


示例6: test_messy

def test_messy():
    from sympy import (laplace_transform, Si, Shi, Chi, atan, Piecewise,
                       acoth, E1, besselj, acosh, asin, And, re,
                       fourier_transform, sqrt)
    assert laplace_transform(Si(x), x, s) == ((-atan(s) + pi/2)/s, 0, True)

    assert laplace_transform(Shi(x), x, s) == (acoth(s)/s, 1, True)

    # where should the logs be simplified?
    assert laplace_transform(Chi(x), x, s) == \
        ((log(s**(-2)) - log((s**2 - 1)/s**2))/(2*s), 1, True)

    # TODO maybe simplify the inequalities?
    assert laplace_transform(besselj(a, x), x, s)[1:] == \
        (0, And(S(0) < re(a/2) + S(1)/2, S(0) < re(a/2) + 1))

    # NOTE s < 0 can be done, but argument reduction is not good enough yet
    assert fourier_transform(besselj(1, x)/x, x, s, noconds=False) == \
        (Piecewise((0, 4*abs(pi**2*s**2) > 1),
                   (2*sqrt(-4*pi**2*s**2 + 1), True)), s > 0)
    # TODO FT(besselj(0,x)) - conditions are messy (but for acceptable reasons)
    #                       - folding could be better

    assert integrate(E1(x)*besselj(0, x), (x, 0, oo), meijerg=True) == \
        log(1 + sqrt(2))
    assert integrate(E1(x)*besselj(1, x), (x, 0, oo), meijerg=True) == \
        log(S(1)/2 + sqrt(2)/2)

    assert integrate(1/x/sqrt(1 - x**2), x, meijerg=True) == \
        Piecewise((-acosh(1/x), 1 < abs(x**(-2))), (I*asin(1/x), True))
开发者ID:chaffra,项目名称:sympy,代码行数:30,代码来源:test_meijerint.py


示例7: test_expr_to_holonomic

def test_expr_to_holonomic():
    x = symbols('x')
    R, Dx = DifferentialOperators(QQ.old_poly_ring(x), 'Dx')
    p = expr_to_holonomic((sin(x)/x)**2)
    q = HolonomicFunction(8*x + (4*x**2 + 6)*Dx + 6*x*Dx**2 + x**2*Dx**3, x, 0, \
        [1, 0, -2/3])
    assert p == q
    p = expr_to_holonomic(1/(1+x**2)**2)
    q = HolonomicFunction(4*x + (x**2 + 1)*Dx, x, 0, 1)
    assert p == q
    p = expr_to_holonomic(exp(x)*sin(x)+x*log(1+x))
    q = HolonomicFunction((2*x**3 + 10*x**2 + 20*x + 18) + (-2*x**4 - 10*x**3 - 20*x**2 \
        - 18*x)*Dx + (2*x**5 + 6*x**4 + 7*x**3 + 8*x**2 + 10*x - 4)*Dx**2 + \
        (-2*x**5 - 5*x**4 - 2*x**3 + 2*x**2 - x + 4)*Dx**3 + (x**5 + 2*x**4 - x**3 - \
        7*x**2/2 + x + 5/2)*Dx**4, x, 0, [0, 1, 4, -1])
    assert p == q
    p = expr_to_holonomic(x*exp(x)+cos(x)+1)
    q = HolonomicFunction((-x - 3)*Dx + (x + 2)*Dx**2 + (-x - 3)*Dx**3 + (x + 2)*Dx**4, x, \
        0, [2, 1, 1, 3])
    assert p == q
    assert (x*exp(x)+cos(x)+1).series(n=10) == p.series(n=10)
    p = expr_to_holonomic(log(1 + x)**2 + 1)
    q = HolonomicFunction(Dx + (3*x + 3)*Dx**2 + (x**2 + 2*x + 1)*Dx**3, x, 0, [1, 0, 2])
    assert p == q
    p = expr_to_holonomic(erf(x)**2 + x)
    q = HolonomicFunction((8*x**4 - 2*x**2 + 2)*Dx**2 + (6*x**3 - x/2)*Dx**3 + \
        (x**2+ 1/4)*Dx**4, x, 0, [0, 1, 8/pi, 0])
    assert p == q
    p = expr_to_holonomic(cosh(x)*x)
    q = HolonomicFunction((-x**2 + 2) -2*x*Dx + x**2*Dx**2, x, 0, [0, 1])
    assert p == q
    p = expr_to_holonomic(besselj(2, x))
    q = HolonomicFunction((x**2 - 4) + x*Dx + x**2*Dx**2, x, 0, [0, 0])
    assert p == q
    p = expr_to_holonomic(besselj(0, x) + exp(x))
    q = HolonomicFunction((-x**2 - x/2 + 1/2) + (x**2 - x/2 - 3/2)*Dx + (-x**2 + x/2 + 1)*Dx**2 +\
        (x**2 + x/2)*Dx**3, x, 0, [2, 1, 1/2])
    assert p == q
    p = expr_to_holonomic(sin(x)**2/x)
    q = HolonomicFunction(4 + 4*x*Dx + 3*Dx**2 + x*Dx**3, x, 0, [0, 1, 0])
    assert p == q
    p = expr_to_holonomic(sin(x)**2/x, x0=2)
    q = HolonomicFunction((4) + (4*x)*Dx + (3)*Dx**2 + (x)*Dx**3, x, 2, [sin(2)**2/2,
        sin(2)*cos(2) - sin(2)**2/4, -3*sin(2)**2/4 + cos(2)**2 - sin(2)*cos(2)])
    assert p == q
    p = expr_to_holonomic(log(x)/2 - Ci(2*x)/2 + Ci(2)/2)
    q = HolonomicFunction(4*Dx + 4*x*Dx**2 + 3*Dx**3 + x*Dx**4, x, 0, \
        [-log(2)/2 - EulerGamma/2 + Ci(2)/2, 0, 1, 0])
    assert p == q
    p = p.to_expr()
    q = log(x)/2 - Ci(2*x)/2 + Ci(2)/2
    assert p == q
    p = expr_to_holonomic(x**(S(1)/2), x0=1)
    q = HolonomicFunction(x*Dx - 1/2, x, 1, 1)
    assert p == q
    p = expr_to_holonomic(sqrt(1 + x**2))
    q = HolonomicFunction((-x) + (x**2 + 1)*Dx, x, 0, 1)
    assert p == q
开发者ID:Kogorushi,项目名称:sympy,代码行数:58,代码来源:test_holonomic.py


示例8: test_rewrite

def test_rewrite():
    from sympy import polar_lift, exp, I
    assert besselj(n, z).rewrite(jn) == sqrt(2*z/pi)*jn(n - S(1)/2, z)
    assert bessely(n, z).rewrite(yn) == sqrt(2*z/pi)*yn(n - S(1)/2, 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(besseli(nu, z), besseli(nu, z).rewrite(besselj), z)
开发者ID:Abhityagi16,项目名称:sympy,代码行数:11,代码来源:test_bessel.py


示例9: test_laplace_transform

def test_laplace_transform():
    LT = laplace_transform
    a, b, c, = symbols('a b c', positive=True)
    t = symbols('t')
    w = Symbol("w")
    f = Function("f")

    # Test unevaluated form
    assert laplace_transform(f(t), t, w) == LaplaceTransform(f(t), t, w)
    assert inverse_laplace_transform(f(w), w, t, plane=0) == InverseLaplaceTransform(f(w), w, t, 0)

    # test a bug
    spos = symbols('s', positive=True)
    assert LT(exp(t), t, spos)[:2] == (1/(spos - 1), True)

    # basic tests from wikipedia

    assert LT((t-a)**b*exp(-c*(t-a))*Heaviside(t-a), t, s) \
           == ((s + c)**(-b - 1)*exp(-a*s)*gamma(b + 1), -c, True)
    assert LT(t**a, t, s) == (s**(-a - 1)*gamma(a + 1), 0, True)
    assert LT(Heaviside(t), t, s) == (1/s, 0, True)
    assert LT(Heaviside(t - a), t, s) == (exp(-a*s)/s, 0, True)
    assert LT(1 - exp(-a*t), t, s) == (a/(s*(a + s)), 0, True)

    assert LT((exp(2*t)-1)*exp(-b - t)*Heaviside(t)/2, t, s, noconds=True) \
           == exp(-b)/(s**2 - 1)

    assert LT(exp(t), t, s)[:2] == (1/(s-1), 1)
    assert LT(exp(2*t), t, s)[:2] == (1/(s-2), 2)
    assert LT(exp(a*t), t, s)[:2] == (1/(s-a), a)

    assert LT(log(t/a), t, s) == ((log(a) + log(s) + EulerGamma)/(-s), 0, True)

    assert LT(erf(t), t, s) == ((-erf(s/2) + 1)*exp(s**2/4)/s, 0, True)

    assert LT(sin(a*t), t, s) == (a/(a**2 + s**2), 0, True)
    assert LT(cos(a*t), t, s) == (s/(a**2 + s**2), 0, True)
    # TODO would be nice to have these come out better
    assert LT(exp(-a*t)*sin(b*t), t, s) == (1/b/(1 + (a + s)**2/b**2), -a, True)
    assert LT(exp(-a*t)*cos(b*t), t, s) == \
           (1/(s + a)/(1 + b**2/(a + s)**2), -a, True)
    # TODO sinh, cosh have delicate cancellation

    assert LT(besselj(0, t), t, s) == (1/sqrt(1 + s**2), 0, True)
    assert LT(besselj(1, t), t, s) == (1 - 1/sqrt(1 + 1/s**2), 0, True)
    # TODO general order works, but is a *mess*
    # TODO besseli also works, but is an even greater mess

    # test a bug in conditions processing
    # TODO the auxiliary condition should be recognised/simplified
    assert LT(exp(t)*cos(t), t, s)[:-1] in [
        ((s - 1)/(s**2 - 2*s + 2), -oo),
        ((s - 1)/((s - 1)**2 + 1), -oo),
        ]
开发者ID:goodok,项目名称:sympy,代码行数:54,代码来源:test_transforms.py


示例10: test_besselsimp

def test_besselsimp():
    from sympy import besselj, besseli, besselk, bessely, jn, yn, exp_polar, cosh
    assert besselsimp(exp(-I*pi*y/2)*besseli(y, z*exp_polar(I*pi/2))) == \
           besselj(y, z)
    assert besselsimp(exp(-I*pi*a/2)*besseli(a, 2*sqrt(x)*exp_polar(I*pi/2))) == \
           besselj(a, 2*sqrt(x))
    assert besselsimp(sqrt(2)*sqrt(pi)*x**(S(1)/4)*exp(I*pi/4)*exp(-I*pi*a/2) * \
                      besseli(-S(1)/2, sqrt(x)*exp_polar(I*pi/2)) * \
                      besseli(a, sqrt(x)*exp_polar(I*pi/2))/2) == \
           besselj(a, sqrt(x)) * cos(sqrt(x))
    assert besselsimp(besseli(S(-1)/2, z)) == sqrt(2)*cosh(z)/(sqrt(pi)*sqrt(z))
    assert besselsimp(besseli(a, z*exp_polar(-I*pi/2))) == exp(-I*pi*a/2)*besselj(a, z)
开发者ID:marshall2389,项目名称:sympy,代码行数:12,代码来源:test_simplify.py


示例11: test_branching

def test_branching():
    from sympy import exp_polar, polar_lift, Symbol, I, exp
    assert besselj(polar_lift(k), x) == besselj(k, x)
    assert besseli(polar_lift(k), x) == besseli(k, x)

    n = Symbol('n', integer=True)
    assert besselj(n, exp_polar(2*pi*I)*x) == besselj(n, x)
    assert besselj(n, polar_lift(x)) == besselj(n, x)
    assert besseli(n, exp_polar(2*pi*I)*x) == besseli(n, x)
    assert besseli(n, polar_lift(x)) == besseli(n, x)

    def tn(func, s):
        from random import uniform
        c = uniform(1, 5)
        expr = func(s, c*exp_polar(I*pi)) - func(s, c*exp_polar(-I*pi))
        eps = 1e-15
        expr2 = func(s + eps, -c + eps*I) - func(s + eps, -c - eps*I)
        return abs(expr.n() - expr2.n()).n() < 1e-10

    nu = Symbol('nu')
    assert besselj(nu, exp_polar(2*pi*I)*x) == exp(2*pi*I*nu)*besselj(nu, x)
    assert besseli(nu, exp_polar(2*pi*I)*x) == exp(2*pi*I*nu)*besseli(nu, x)
    assert tn(besselj, 2)
    assert tn(besselj, pi)
    assert tn(besselj, I)
    assert tn(besseli, 2)
    assert tn(besseli, pi)
    assert tn(besseli, I)
开发者ID:Abhityagi16,项目名称:sympy,代码行数:28,代码来源:test_bessel.py


示例12: test_rewrite

def test_rewrite():
    from sympy import polar_lift, exp, I

    assert besselj(n, z).rewrite(jn) == sqrt(2*z/pi)*jn(n - S(1)/2, z)
    assert bessely(n, z).rewrite(yn) == sqrt(2*z/pi)*yn(n - S(1)/2, 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(1)/2, z)/2
    assert jn(order, z).rewrite(bessely) == (-1)**nu*sqrt(2)*sqrt(pi)*sqrt(1/z)*bessely(-order - S(1)/2, 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)
开发者ID:KonstantinTogoi,项目名称:sympy,代码行数:59,代码来源:test_bessel.py


示例13: test_hyper

def test_hyper():
    for x in sorted(exparg):
        test("erf", x, N(sp.erf(x)))
    for x in sorted(exparg):
        test("erfc", x, N(sp.erfc(x)))

    gamarg = FiniteSet(*(x+S(1)/12 for x in exparg))
    betarg = ProductSet(gamarg, gamarg)
    for x in sorted(gamarg):
        test("lgamma", x, N(sp.log(abs(sp.gamma(x)))))
    for x in sorted(gamarg):
        test("gamma", x, N(sp.gamma(x)))
    for x, y in sorted(betarg, key=lambda (x, y): (y, x)):
        test("beta", x, y, N(sp.beta(x, y)))

    pgamarg = FiniteSet(S(1)/12, S(1)/3, S(3)/2, 5)
    pgamargp = ProductSet(gamarg & Interval(0, oo, True), pgamarg)
    for a, x in sorted(pgamargp):
        test("pgamma", a, x, N(sp.lowergamma(a, x)))
    for a, x in sorted(pgamargp):
        test("pgammac", a, x, N(sp.uppergamma(a, x)))
    for a, x in sorted(pgamargp):
        test("pgammar", a, x, N(sp.lowergamma(a, x)/sp.gamma(a)))
    for a, x in sorted(pgamargp):
        test("pgammarc", a, x, N(sp.uppergamma(a, x)/sp.gamma(a)))
    for a, x in sorted(pgamargp):
        test("ipgammarc", a, N(sp.uppergamma(a, x)/sp.gamma(a)), x)

    pbetargp = [(a, b, x) for a, b, x in ProductSet(betarg, pgamarg)
                if a > 0 and b > 0 and x < 1]
    pbetargp.sort(key=lambda (a, b, x): (b, a, x))
    for a, b, x in pbetargp:
        test("pbeta", a, b, x, mp.betainc(mpf(a), mpf(b), x2=mpf(x)))
    for a, b, x in pbetargp:
        test("pbetar", a, b, x, mp.betainc(mpf(a), mpf(b), x2=mpf(x),
                                           regularized=True))
    for a, b, x in pbetargp:
        test("ipbetar", a, b, mp.betainc(mpf(a), mpf(b), x2=mpf(x),
                                         regularized=True), x)

    for x in sorted(posarg):
        test("j0", x, N(sp.besselj(0, x)))
    for x in sorted(posarg):
        test("j1", x, N(sp.besselj(1, x)))
    for x in sorted(posarg-FiniteSet(0)):
        test("y0", x, N(sp.bessely(0, x)))
    for x in sorted(posarg-FiniteSet(0)):
        test("y1", x, N(sp.bessely(1, x)))
开发者ID:zholos,项目名称:qml,代码行数:48,代码来源:libm.py


示例14: test_inverse_laplace_transform

def test_inverse_laplace_transform():
    from sympy import sinh, cosh, besselj, besseli, simplify, factor_terms

    ILT = inverse_laplace_transform
    a, b, c, = symbols("a b c", positive=True, finite=True)
    t = symbols("t")

    def simp_hyp(expr):
        return factor_terms(expand_mul(expr)).rewrite(sin)

    # just test inverses of all of the above
    assert ILT(1 / s, s, t) == Heaviside(t)
    assert ILT(1 / s ** 2, s, t) == t * Heaviside(t)
    assert ILT(1 / s ** 5, s, t) == t ** 4 * Heaviside(t) / 24
    assert ILT(exp(-a * s) / s, s, t) == Heaviside(t - a)
    assert ILT(exp(-a * s) / (s + b), s, t) == exp(b * (a - t)) * Heaviside(-a + t)
    assert ILT(a / (s ** 2 + a ** 2), s, t) == sin(a * t) * Heaviside(t)
    assert ILT(s / (s ** 2 + a ** 2), s, t) == cos(a * t) * Heaviside(t)
    # TODO is there a way around simp_hyp?
    assert simp_hyp(ILT(a / (s ** 2 - a ** 2), s, t)) == sinh(a * t) * Heaviside(t)
    assert simp_hyp(ILT(s / (s ** 2 - a ** 2), s, t)) == cosh(a * t) * Heaviside(t)
    assert ILT(a / ((s + b) ** 2 + a ** 2), s, t) == exp(-b * t) * sin(a * t) * Heaviside(t)
    assert ILT((s + b) / ((s + b) ** 2 + a ** 2), s, t) == exp(-b * t) * cos(a * t) * Heaviside(t)
    # TODO sinh/cosh shifted come out a mess. also delayed trig is a mess
    # TODO should this simplify further?
    assert ILT(exp(-a * s) / s ** b, s, t) == (t - a) ** (b - 1) * Heaviside(t - a) / gamma(b)

    assert ILT(exp(-a * s) / sqrt(1 + s ** 2), s, t) == Heaviside(t - a) * besselj(
        0, a - t
    )  # note: besselj(0, x) is even

    # XXX ILT turns these branch factor into trig functions ...
    assert simplify(
        ILT(a ** b * (s + sqrt(s ** 2 - a ** 2)) ** (-b) / sqrt(s ** 2 - a ** 2), s, t).rewrite(exp)
    ) == Heaviside(t) * besseli(b, a * t)
    assert ILT(a ** b * (s + sqrt(s ** 2 + a ** 2)) ** (-b) / sqrt(s ** 2 + a ** 2), s, t).rewrite(exp) == Heaviside(
        t
    ) * besselj(b, a * t)

    assert ILT(1 / (s * sqrt(s + 1)), s, t) == Heaviside(t) * erf(sqrt(t))
    # TODO can we make erf(t) work?

    assert ILT(1 / (s ** 2 * (s ** 2 + 1)), s, t) == (t - sin(t)) * Heaviside(t)

    assert ILT((s * eye(2) - Matrix([[1, 0], [0, 2]])).inv(), s, t) == Matrix(
        [[exp(t) * Heaviside(t), 0], [0, exp(2 * t) * Heaviside(t)]]
    )
开发者ID:whimsy-Pan,项目名称:sympy,代码行数:47,代码来源:test_transforms.py


示例15: test_bessel_rand

def test_bessel_rand():
    assert td(besselj(randcplx(), z), z)
    assert td(bessely(randcplx(), z), z)
    assert td(besseli(randcplx(), z), z)
    assert td(besselk(randcplx(), z), z)
    assert td(hankel1(randcplx(), z), z)
    assert td(hankel2(randcplx(), z), z)
    assert td(jn(randcplx(), z), z)
    assert td(yn(randcplx(), z), z)
开发者ID:Abhityagi16,项目名称:sympy,代码行数:9,代码来源:test_bessel.py


示例16: test_inverse_laplace_transform

def test_inverse_laplace_transform():
    from sympy import (expand, sinh, cosh, besselj, besseli, exp_polar,
                       unpolarify, simplify)
    ILT = inverse_laplace_transform
    a, b, c, = symbols('a b c', positive=True)
    t = symbols('t')

    def simp_hyp(expr):
        return expand(expand(expr).rewrite(sin))

    # just test inverses of all of the above
    assert ILT(1/s, s, t) == Heaviside(t)
    assert ILT(1/s**2, s, t) == t*Heaviside(t)
    assert ILT(1/s**5, s, t) == t**4*Heaviside(t)/24
    assert ILT(exp(-a*s)/s, s, t) == Heaviside(t - a)
    assert ILT(exp(-a*s)/(s + b), s, t) == exp(b*(a - t))*Heaviside(-a + t)
    assert ILT(a/(s**2 + a**2), s, t) == sin(a*t)*Heaviside(t)
    assert ILT(s/(s**2 + a**2), s, t) == cos(a*t)*Heaviside(t)
    # TODO is there a way around simp_hyp?
    assert simp_hyp(ILT(a/(s**2 - a**2), s, t)) == sinh(a*t)*Heaviside(t)
    assert simp_hyp(ILT(s/(s**2 - a**2), s, t)) == cosh(a*t)*Heaviside(t)
    assert ILT(a/((s + b)**2 + a**2), s, t) == exp(-b*t)*sin(a*t)*Heaviside(t)
    assert ILT(
        (s + b)/((s + b)**2 + a**2), s, t) == exp(-b*t)*cos(a*t)*Heaviside(t)
    # TODO sinh/cosh shifted come out a mess. also delayed trig is a mess
    # TODO should this simplify further?
    assert ILT(exp(-a*s)/s**b, s, t) == \
        (t - a)**(b - 1)*Heaviside(t - a)/gamma(b)

    assert ILT(exp(-a*s)/sqrt(1 + s**2), s, t) == \
        Heaviside(t - a)*besselj(0, a - t)  # note: besselj(0, x) is even

    # XXX ILT turns these branch factor into trig functions ...
    assert simplify(ILT(a**b*(s + sqrt(s**2 - a**2))**(-b)/sqrt(s**2 - a**2),
                    s, t).rewrite(exp)) == \
        Heaviside(t)*besseli(b, a*t)
    assert ILT(a**b*(s + sqrt(s**2 + a**2))**(-b)/sqrt(s**2 + a**2),
               s, t).rewrite(exp) == \
        Heaviside(t)*besselj(b, a*t)

    assert ILT(1/(s*sqrt(s + 1)), s, t) == Heaviside(t)*erf(sqrt(t))
开发者ID:Acebulf,项目名称:sympy,代码行数:41,代码来源:test_transforms.py


示例17: test_inversion

def test_inversion():
    from sympy import piecewise_fold, besselj, sqrt, I, sin, cos, Heaviside
    def inv(f): return piecewise_fold(meijerint_inversion(f, s, t))
    assert inv(1/(s**2 + 1)) == sin(t)*Heaviside(t)
    assert inv(s/(s**2 + 1)) == cos(t)*Heaviside(t)
    assert inv(exp(-s)/s) == Heaviside(t - 1)
    assert inv(1/sqrt(1 + s**2)) == besselj(0, t)*Heaviside(t)

    # Test some antcedents checking.
    assert meijerint_inversion(sqrt(s)/sqrt(1 + s**2), s, t) is None
    assert inv(exp(s**2)) is None
    assert meijerint_inversion(exp(-s**2), s, t) is None
开发者ID:BDGLunde,项目名称:sympy,代码行数:12,代码来源:test_meijerint.py


示例18: test_laplace_transform

def test_laplace_transform():
    LT = laplace_transform
    a, b, c, = symbols('a b c', positive=True)
    t = symbols('t')

    # basic tests from wikipedia

    assert LT((t-a)**b*exp(-c*(t-a))*Heaviside(t-a), t, s) \
           == ((s + c)**(-b - 1)*exp(-a*s)*gamma(b + 1), -c, True)
    assert LT(t**a, t, s) == (s**(-a - 1)*gamma(a + 1), 0, True)
    assert LT(Heaviside(t), t, s) == (1/s, 0, True)
    assert LT(Heaviside(t - a), t, s) == (exp(-a*s)/s, 0, True)
    assert LT(1 - exp(-a*t), t, s) == (a/(s*(a + s)), 0, True)

    assert LT((exp(2*t)-1)*exp(-b - t)*Heaviside(t)/2, t, s, noconds=True) \
           == exp(-b)/(s**2 - 1)

    assert LT(exp(t), t, s)[0:2] == (1/(s-1), 1)
    assert LT(exp(2*t), t, s)[0:2] == (1/(s-2), 2)
    assert LT(exp(a*t), t, s)[0:2] == (1/(s-a), a)

    lt = LT(log(t/a), t, s)
    assert lt[1:] == (0, True)
    # TODO hyperexpand is not clever enough to recognise this on its own
    assert hyperexpand(lt[0], allow_hyper=True) == (-log(a*s) - EulerGamma)/s

    assert LT(erf(t), t, s) == ((-erf(s/2) + 1)*exp(s**2/4)/s, 0, True)

    assert LT(sin(a*t), t, s) == (a/(a**2 + s**2), 0, True)
    assert LT(cos(a*t), t, s) == (s/(a**2 + s**2), 0, True)
    # TODO would be nice to have these come out better
    assert LT(exp(-a*t)*sin(b*t), t, s) == (1/b/(1 + (a + s)**2/b**2), -a, True)
    assert LT(exp(-a*t)*cos(b*t), t, s) == \
           (sqrt((a + s)**2)/b**2/(1 + (a + s)**2/b**2), -a, True)
    # TODO sinh, cosh have delicate cancellation

    # TODO conditions are a mess
    assert LT(besselj(0, t), t, s, noconds=True) == 1/sqrt(1 + s**2)
    assert LT(besselj(1, t), t, s, noconds=True) == 1 - 1/sqrt(1 + 1/s**2)
开发者ID:Kimay,项目名称:sympy,代码行数:39,代码来源:test_transforms.py


示例19: test_bessel_eval

def test_bessel_eval():
    from sympy import I, Symbol
    n, m, k = Symbol('n', integer=True), Symbol('m'), Symbol('k', integer=True, zero=False)

    for f in [besselj, besseli]:
        assert f(0, 0) == S.One
        assert f(2.1, 0) == S.Zero
        assert f(-3, 0) == S.Zero
        assert f(-10.2, 0) == S.ComplexInfinity
        assert f(1 + 3*I, 0) == S.Zero
        assert f(-3 + I, 0) == S.ComplexInfinity
        assert f(-2*I, 0) == S.NaN
        assert f(n, 0) != S.One and f(n, 0) != S.Zero
        assert f(m, 0) != S.One and f(m, 0) != S.Zero
        assert f(k, 0) == S.Zero

    assert bessely(0, 0) == S.NegativeInfinity
    assert besselk(0, 0) == S.Infinity
    for f in [bessely, besselk]:
        assert f(1 + I, 0) == S.ComplexInfinity
        assert f(I, 0) == S.NaN

    for f in [besselj, bessely]:
        assert f(m, S.Infinity) == S.Zero
        assert f(m, S.NegativeInfinity) == S.Zero

    for f in [besseli, besselk]:
        assert f(m, I*S.Infinity) == S.Zero
        assert f(m, I*S.NegativeInfinity) == S.Zero

    for f in [besseli, besselk]:
        assert f(-4, z) == f(4, z)
        assert f(-3, z) == f(3, z)
        assert f(-n, z) == f(n, z)
        assert f(-m, z) != f(m, z)

    for f in [besselj, bessely]:
        assert f(-4, z) == f(4, z)
        assert f(-3, z) == -f(3, z)
        assert f(-n, z) == (-1)**n*f(n, z)
        assert f(-m, z) != (-1)**m*f(m, z)

    for f in [besselj, besseli]:
        assert f(m, -z) == (-z)**m*z**(-m)*f(m, z)

    assert besseli(2, -z) == besseli(2, z)
    assert besseli(3, -z) == -besseli(3, z)

    assert besselj(0, -z) == besselj(0, z)
    assert besselj(1, -z) == -besselj(1, z)

    assert besseli(0, I*z) == besselj(0, z)
    assert besseli(1, I*z) == I*besselj(1, z)
    assert besselj(3, I*z) == -I*besseli(3, z)
开发者ID:KonstantinTogoi,项目名称:sympy,代码行数:54,代码来源:test_bessel.py


示例20: test_laplace_transform

def test_laplace_transform():
    LT = laplace_transform
    a, b, c, = symbols('a b c', positive=True)
    t = symbols('t')

    # test a bug
    spos = symbols('s', positive=True)
    assert LT(exp(t), t, spos)[:2] == (1/(spos - 1), True)

    # basic tests from wikipedia

    assert LT((t-a)**b*exp(-c*(t-a))*Heaviside(t-a), t, s) \
           == ((s + c)**(-b - 1)*exp(-a*s)*gamma(b + 1), -c, True)
    assert LT(t**a, t, s) == (s**(-a - 1)*gamma(a + 1), 0, True)
    assert LT(Heaviside(t), t, s) == (1/s, 0, True)
    assert LT(Heaviside(t - a), t, s) == (exp(-a*s)/s, 0, True)
    assert LT(1 - exp(-a*t), t, s) == (a/(s*(a + s)), 0, True)

    assert LT((exp(2*t)-1)*exp(-b - t)*Heaviside(t)/2, t, s, noconds=True) \
           == exp(-b)/(s**2 - 1)

    assert LT(exp(t), t, s)[0:2] == (1/(s-1), 1)
    assert LT(exp(2*t), t, s)[0:2] == (1/(s-2), 2)
    assert LT(exp(a*t), t, s)[0:2] == (1/(s-a), a)

    assert LT(log(t/a), t, s) == ((log(a) + log(s) + EulerGamma)/(-s), 0, True)

    assert LT(erf(t), t, s) == ((-erf(s/2) + 1)*exp(s**2/4)/s, 0, True)

    assert LT(sin(a*t), t, s) == (a/(a**2 + s**2), 0, True)
    assert LT(cos(a*t), t, s) == (s/(a**2 + s**2), 0, True)
    # TODO would be nice to have these come out better
    assert LT(exp(-a*t)*sin(b*t), t, s) == (1/b/(1 + (a + s)**2/b**2), -a, True)
    assert LT(exp(-a*t)*cos(b*t), t, s) == \
           (1/(s + a)/(1 + b**2/(a + s)**2), -a, True)
    # TODO sinh, cosh have delicate cancellation

    assert LT(besselj(0, t), t, s) == (1/sqrt(1 + s**2), 0, True)
    assert LT(besselj(1, t), t, s) == (1 - 1/sqrt(1 + 1/s**2), 0, True)
开发者ID:abhishek070193,项目名称:sympy,代码行数:39,代码来源:test_transforms.py



注:本文中的sympy.besselj函数示例由纯净天空整理自Github/MSDocs等源码及文档管理平台,相关代码片段筛选自各路编程大神贡献的开源项目,源码版权归原作者所有,传播和使用请参考对应项目的License;未经允许,请勿转载。


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