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)
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
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
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)
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))
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
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
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)
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),
]
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)
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)
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)
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)))
def test_besselsimp():
from sympy import besselj, besseli, exp_polar, cosh, cosine_transform
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)
assert cosine_transform(1/t*sin(a/t), t, y) == \
sqrt(2)*sqrt(pi)*besselj(0, 2*sqrt(a)*sqrt(y))/2
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)]]
)
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)
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))
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
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)
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)
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)
def __init__(self, **kwargs):
a = self.a
nu = self.nu
k = self.k
r, th = sympy.symbols('r th')
v_asympt01 = get_v_asympt0(0, k, nu)
v_asympt03 = get_v_asympt0(1, k, nu)
self.v_asympt = (
v_asympt01 * sympy.sin(nu/2*(th-a)) +
v_asympt03 * sympy.sin(3*nu/2*(th-2*np.pi))
) * get_tapering_func(self.R)
self.v_series = (
get_v_asympt0(0, k, nu, nterms=10) * sympy.sin(nu/2*(th-a)) +
get_v_asympt0(1, k, nu, nterms=10) * sympy.sin(3*nu/2*(th-2*np.pi))
)
self.g = (
(th - a) / (2*np.pi - a) * sympy.besselj(nu/2, k*r)
+ (th - 2*np.pi) / (a - 2*np.pi) * sympy.besselj(3*nu/2, k*r)
)
def test_pmint_besselj():
f = besselj(nu + 1, x)/besselj(nu, x)
g = nu*log(x) - log(besselj(nu, x))
assert heurisch(f, x) == g
f = (nu*besselj(nu, x) - x*besselj(nu + 1, x))/x
g = besselj(nu, x)
assert heurisch(f, x) == g
f = jn(nu + 1, x)/jn(nu, x)
g = nu*log(x) - log(jn(nu, x))
assert heurisch(f, x) == g
def test_pmint_bessel_products():
# Note: Derivatives of Bessel functions have many forms.
# Recurrence relations are needed for comparisons.
if ON_TRAVIS:
skip("Too slow for travis.")
f = x*besselj(nu, x)*bessely(nu, 2*x)
g = -2*x*besselj(nu, x)*bessely(nu - 1, 2*x)/3 + x*besselj(nu - 1, x)*bessely(nu, 2*x)/3
assert heurisch(f, x) == g
f = x*besselj(nu, x)*besselk(nu, 2*x)
g = -2*x*besselj(nu, x)*besselk(nu - 1, 2*x)/5 - x*besselj(nu - 1, x)*besselk(nu, 2*x)/5
assert heurisch(f, x) == g
def __init__(self, **kwargs):
a = self.a
nu = self.nu
k = self.k
K = self.K
R = self.R
r, th = sympy.symbols('r th')
v_asympt01 = get_v_asympt0(K, k, nu)
self.v_asympt = (
get_v_asympt0(K, k, nu) * sympy.sin((K+1/2)*nu*(th-a))
) * get_tapering_func(R)
self.v_series = get_v_asympt0(K, k, nu, nterms=10)* sympy.sin((K+1/2)*nu*(th-a))
phi1 = sympy.besselj((K+1/2)*nu, k*r)
if alt_phi1_ext:
phi1 += sympy.Piecewise((0, r<R), ((r-R)**5, True))
self.g = (th - a) / (2*np.pi - a) * (phi1)
def test_inverse_laplace_transform():
from sympy import expand, sinh, cosh, besselj, besseli, exp_polar, unpolarify
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)/factorial(4)
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(t - a)
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
# TODO besselsimp would be good to have
# these are re-enabled in a later commit
#assert ILT(a**b*(s + sqrt(s**2 - a**2))**(-b)/sqrt(s**2 - a**2), s, t) == \
# (t**2)**(b/2 + S(1)/2)*Heaviside(t)*besseli(b, a*t*exp_polar(I*pi))*exp_polar(-I*pi*b)/(t*sqrt((t**2)**b))
#assert unpolarify(ILT(a**b*(s + sqrt(s**2 + a**2))**(-b)/sqrt(s**2 + a**2),
# s, t).rewrite(besselj)) == \
# (t**2)**(b/2 + S(1)/2)*exp(-I*pi*b)*Heaviside(t)*besselj(b, a*t*exp_polar(I*pi))/(t*sqrt((t**2)**b))
assert ILT(1/(s*sqrt(s+1)), s, t) == Heaviside(t)*erf(sqrt(t))
def test_pmint_bessel_products():
# Note: Derivatives of Bessel functions have many forms.
# Recurrence relations are needed for comparisons.
if ON_TRAVIS:
skip("Too slow for travis.")
f = x * besselj(nu, x) * bessely(nu, 2 * x)
g = -2 * x * besselj(nu, x) * bessely(nu - 1, 2 * x) / 3 + x * besselj(
nu - 1, x) * bessely(nu, 2 * x) / 3
assert heurisch(f, x) == g
f = x * besselj(nu, x) * besselk(nu, 2 * x)
g = -2 * x * besselj(nu, x) * besselk(nu - 1, 2 * x) / 5 - x * besselj(
nu - 1, x) * besselk(nu, 2 * x) / 5
assert heurisch(f, x) == g
def fourier_transform(self) -> sy.Expr:
r"""
The 2D Fourier transform of :math:`Z^m_n`.
This function essentially implements eq. (7) of [Tatulli_2013]_.
.. note::
Compared to [Tatulli_2013]_, we are using a slightly
different notation. Instead of indexing the dimensions of
the Fourier space (or :math:`k`-space) using :math:`\kappa`
and :math:`\alpha`, we use :math:`k_1` and :math:`k_2`.
Returns:
The 2D Fourier transform of :math:`Z^m_n`, that is,
:math:`\mathcal{F}\lbrace Z^m_n \rbrace (k_1, k_2)`,
as a `sy.Expr`.
"""
# Define symbols for k1 and k2
k1 = sy.Symbol('k1')
k2 = sy.Symbol('k2')
# Define the first factor, which only depends on n
factor_1 = (sy.Pow(-1, self.n) * sy.sqrt(self.n + 1) / (sy.pi * k1) *
sy.besselj(2 * sy.pi * k1, self.n + 1))
# Define the second factor that also depends on m
if self.m == 0:
factor_2 = sy.Pow(-1, self.n / 2)
elif self.m > 0:
factor_2 = (sy.sqrt(2) * sy.Pow(-1, (self.n - self.m) / 2) *
sy.Pow(sy.I, self.m) * sy.cos(self.m * k2))
else:
factor_2 = (sy.sqrt(2) * sy.Pow(-1, (self.n + self.m) / 2) *
sy.Pow(sy.I, -self.m) * sy.sin(-self.m * k2))
return sy.nsimplify(sy.simplify(factor_1 * factor_2))
def test_meromorphic():
assert besselj(2, x).is_meromorphic(x, 1) == True
assert besselj(2, x).is_meromorphic(x, 0) == True
assert besselj(2, x).is_meromorphic(x, oo) == False
assert besselj(S(2) / 3, x).is_meromorphic(x, 1) == True
assert besselj(S(2) / 3, x).is_meromorphic(x, 0) == False
assert besselj(S(2) / 3, x).is_meromorphic(x, oo) == False
assert besselj(x, 2 * x).is_meromorphic(x, 2) == False
assert besselk(0, x).is_meromorphic(x, 1) == True
assert besselk(2, x).is_meromorphic(x, 0) == True
assert besseli(0, x).is_meromorphic(x, 1) == True
assert besseli(2, x).is_meromorphic(x, 0) == True
assert bessely(0, x).is_meromorphic(x, 1) == True
assert bessely(0, x).is_meromorphic(x, 0) == False
assert bessely(2, x).is_meromorphic(x, 0) == True
assert hankel1(3, x**2 + 2 * x).is_meromorphic(x, 1) == True
assert hankel1(0, x).is_meromorphic(x, 0) == False
assert hankel2(11, 4).is_meromorphic(x, 5) == True
assert hn1(6, 7 * x**3 + 4).is_meromorphic(x, 7) == True
assert hn2(3, 2 * x).is_meromorphic(x, 9) == True
assert jn(5, 2 * x + 7).is_meromorphic(x, 4) == True
assert yn(8, x**2 + 11).is_meromorphic(x, 6) == True
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)
def test_to_meijerg():
x = symbols('x')
assert hyperexpand(expr_to_holonomic(sin(x)).to_meijerg()) == sin(x)
assert hyperexpand(expr_to_holonomic(cos(x)).to_meijerg()) == cos(x)
assert hyperexpand(expr_to_holonomic(exp(x)).to_meijerg()) == exp(x)
assert hyperexpand(expr_to_holonomic(
log(x)).to_meijerg()).simplify() == log(x)
assert expr_to_holonomic(4 * x**2 / 3 + 7).to_meijerg() == 4 * x**2 / 3 + 7
assert hyperexpand(
expr_to_holonomic(besselj(2, x),
lenics=3).to_meijerg()) == besselj(2, x)
p = hyper((-S(1) / 2, -3), (), x)
assert from_hyper(p).to_meijerg() == hyperexpand(p)
p = hyper((S(1), S(3)), (S(2), ), x)
assert (hyperexpand(from_hyper(p).to_meijerg()) -
hyperexpand(p)).expand() == 0
p = from_hyper(hyper((-2, -3), (S(1) / 2, ), x))
s = hyperexpand(hyper((-2, -3), (S(1) / 2, ), x))
C_0 = Symbol('C_0')
C_1 = Symbol('C_1')
D_0 = Symbol('D_0')
assert (hyperexpand(p.to_meijerg()).subs({
C_0: 1,
D_0: 0
}) - s).simplify() == 0
p.singular_ics = [(0, [1]), (S(1) / 2, [0])]
assert (hyperexpand(p.to_meijerg()) - s).simplify() == 0
p = expr_to_holonomic(besselj(S(1) / 2, x), initcond=False)
assert (
p.to_expr() -
(D_0 * sin(x) + C_0 * cos(x) + C_1 * sin(x)) / sqrt(x)).simplify() == 0
p = expr_to_holonomic(
besselj(S(1) / 2, x),
singular_ics=((S(-1) / 2, [sqrt(2) / sqrt(pi),
sqrt(2) / sqrt(pi)]), ))
assert (p.to_expr() - besselj(S(1) / 2, x) -
besselj(S(-1) / 2, x)).simplify() == 0
def test_to_meijerg():
x = symbols('x')
assert hyperexpand(expr_to_holonomic(sin(x)).to_meijerg()) == sin(x)
assert hyperexpand(expr_to_holonomic(cos(x)).to_meijerg()) == cos(x)
assert hyperexpand(expr_to_holonomic(exp(x)).to_meijerg()) == exp(x)
assert hyperexpand(expr_to_holonomic(
log(x)).to_meijerg()).simplify() == log(x)
assert expr_to_holonomic(4 * x**2 / 3 + 7).to_meijerg() == 4 * x**2 / 3 + 7
assert hyperexpand(
expr_to_holonomic(besselj(2, x),
lenics=3).to_meijerg()) == besselj(2, x)
p = hyper((Rational(-1, 2), -3), (), x)
assert from_hyper(p).to_meijerg() == hyperexpand(p)
p = hyper((S.One, S(3)), (S(2), ), x)
assert (hyperexpand(from_hyper(p).to_meijerg()) -
hyperexpand(p)).expand() == 0
p = from_hyper(hyper((-2, -3), (S.Half, ), x))
s = hyperexpand(hyper((-2, -3), (S.Half, ), x))
C_0 = Symbol('C_0')
C_1 = Symbol('C_1')
D_0 = Symbol('D_0')
assert (hyperexpand(p.to_meijerg()).subs({
C_0: 1,
D_0: 0
}) - s).simplify() == 0
p.y0 = {0: [1], S.Half: [0]}
assert (hyperexpand(p.to_meijerg()) - s).simplify() == 0
p = expr_to_holonomic(besselj(S.Half, x), initcond=False)
assert (
p.to_expr() -
(D_0 * sin(x) + C_0 * cos(x) + C_1 * sin(x)) / sqrt(x)).simplify() == 0
p = expr_to_holonomic(
besselj(S.Half, x),
y0={Rational(-1, 2): [sqrt(2) / sqrt(pi),
sqrt(2) / sqrt(pi)]})
assert (p.to_expr() - besselj(S.Half, x) -
besselj(Rational(-1, 2), x)).simplify() == 0
def test_to_meijerg():
x = symbols('x')
assert hyperexpand(expr_to_holonomic(sin(x)).to_meijerg()) == sin(x)
assert hyperexpand(expr_to_holonomic(cos(x)).to_meijerg()) == cos(x)
assert hyperexpand(expr_to_holonomic(exp(x)).to_meijerg()) == exp(x)
assert hyperexpand(expr_to_holonomic(log(x)).to_meijerg()).simplify() == log(x)
assert expr_to_holonomic(4*x**2/3 + 7).to_meijerg() == 4*x**2/3 + 7
assert hyperexpand(expr_to_holonomic(besselj(2, x), lenics=3).to_meijerg()) == besselj(2, x)
p = hyper((-S(1)/2, -3), (), x)
assert from_hyper(p).to_meijerg() == hyperexpand(p)
p = hyper((S(1), S(3)), (S(2), ), x)
assert (hyperexpand(from_hyper(p).to_meijerg()) - hyperexpand(p)).expand() == 0
p = from_hyper(hyper((-2, -3), (S(1)/2, ), x))
s = hyperexpand(hyper((-2, -3), (S(1)/2, ), x))
C_0 = Symbol('C_0')
C_1 = Symbol('C_1')
D_0 = Symbol('D_0')
assert (hyperexpand(p.to_meijerg()).subs({C_0:1, D_0:0}) - s).simplify() == 0
p.y0 = {0: [1], S(1)/2: [0]}
assert (hyperexpand(p.to_meijerg()) - s).simplify() == 0
p = expr_to_holonomic(besselj(S(1)/2, x), initcond=False)
assert (p.to_expr() - (D_0*sin(x) + C_0*cos(x) + C_1*sin(x))/sqrt(x)).simplify() == 0
p = expr_to_holonomic(besselj(S(1)/2, x), y0={S(-1)/2: [sqrt(2)/sqrt(pi), sqrt(2)/sqrt(pi)]})
assert (p.to_expr() - besselj(S(1)/2, x) - besselj(S(-1)/2, x)).simplify() == 0
from sympy import symbols, lambdify, besselj, I
from scipy.special import jv as scipy_besselj
from dolfin import *
mesh = UnitCubeMesh(20, 20, 20)
# Space where the exact solution is represented
Ve = FunctionSpace(mesh, 'DG', 4)
dof_x = Ve.dofmap().tabulate_all_coordinates(mesh).reshape((-1, 3))
X, Y, Z = dof_x[:, 0], dof_x[:, 1], dof_x[:, 2]
# Suppose the solution is besselj(1, x[0]) + besselj(2, x[1]) + besselj(3, x[2])
x, y, z = symbols('x, y, z')
u = (0.00073 - 0.00052 * I) * besselj(0, (1.84 - 1.84 * I) * x)
u_lambda = lambdify(x, u, ['numpy', {'besselj': scipy_besselj}])
# Interpolate manually
# timer = Timer('eval')
# timer.start()
# u_values = u_lambda(X, Y, Z)
# print 'Evaluated %d dofs in % s' % (Ve.dim(), timer.stop())
# Exact solution in Ve
# u = Function(Ve)
# u.vector()[:] = u_values
# Solution space and the hypot. numerical solution
# V = FunctionSpace(mesh, 'CG', 1)
# uh = interpolate(Constant(1), V)
# print errornorm(u, uh)
print u_lambda(1.0)
def test_laplace_transform():
from sympy import fresnels, fresnelc
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 * s) + EulerGamma) / s / -1, 0, True)
assert LT(erf(t), t, s) == ((erfc(s / 2)) * 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) == (b / (b**2 + (a + s)**2), -a, True)
assert LT(exp(-a*t)*cos(b*t), t, s) == \
((a + s)/(b**2 + (a + s)**2), -a, True)
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),
]
# Fresnel functions
assert laplace_transform(fresnels(t), t, s) == \
((-sin(s**2/(2*pi))*fresnels(s/pi) + sin(s**2/(2*pi))/2 -
cos(s**2/(2*pi))*fresnelc(s/pi) + cos(s**2/(2*pi))/2)/s, 0, True)
assert laplace_transform(
fresnelc(t), t,
s) == (((2 * sin(s**2 / (2 * pi)) * fresnelc(s / pi) -
2 * cos(s**2 / (2 * pi)) * fresnels(s / pi) +
sqrt(2) * cos(s**2 / (2 * pi) + pi / 4)) / (2 * s), 0, True))
assert LT(Matrix([[exp(t), t*exp(-t)], [t*exp(-t), exp(t)]]), t, s) ==\
Matrix([
[(1/(s - 1), 1, True), ((s + 1)**(-2), 0, True)],
[((s + 1)**(-2), 0, True), (1/(s - 1), 1, True)]
])
def test_inverse_mellin_transform():
from sympy import (sin, simplify, Max, Min, expand, powsimp, exp_polar,
cos, cot)
IMT = inverse_mellin_transform
assert IMT(gamma(s), s, x, (0, oo)) == exp(-x)
assert IMT(gamma(-s), s, x, (-oo, 0)) == exp(-1 / x)
assert simplify(IMT(s/(2*s**2 - 2), s, x, (2, oo))) == \
(x**2 + 1)*Heaviside(1 - x)/(4*x)
# test passing "None"
assert IMT(1/(s**2 - 1), s, x, (-1, None)) == \
-x*Heaviside(-x + 1)/2 - Heaviside(x - 1)/(2*x)
assert IMT(1/(s**2 - 1), s, x, (None, 1)) == \
-x*Heaviside(-x + 1)/2 - Heaviside(x - 1)/(2*x)
# test expansion of sums
assert IMT(gamma(s) + gamma(s - 1), s, x, (1, oo)) == (x + 1) * exp(-x) / x
# test factorisation of polys
r = symbols('r', real=True)
assert IMT(1/(s**2 + 1), s, exp(-x), (None, oo)
).subs(x, r).rewrite(sin).simplify() \
== sin(r)*Heaviside(1 - exp(-r))
# test multiplicative substitution
_a, _b = symbols('a b', positive=True)
assert IMT(_b**(-s / _a) * factorial(s / _a) / s, s, x,
(0, oo)) == exp(-_b * x**_a)
assert IMT(factorial(_a / _b + s / _b) / (_a + s), s, x,
(-_a, oo)) == x**_a * exp(-x**_b)
def simp_pows(expr):
return simplify(powsimp(expand_mul(expr, deep=False),
force=True)).replace(exp_polar, exp)
# Now test the inverses of all direct transforms tested above
# Section 8.4.2
nu = symbols('nu', real=True, finite=True)
assert IMT(-1 / (nu + s), s, x, (-oo, None)) == x**nu * Heaviside(x - 1)
assert IMT(1 / (nu + s), s, x, (None, oo)) == x**nu * Heaviside(1 - x)
assert simp_pows(IMT(gamma(beta)*gamma(s)/gamma(s + beta), s, x, (0, oo))) \
== (1 - x)**(beta - 1)*Heaviside(1 - x)
assert simp_pows(IMT(gamma(beta)*gamma(1 - beta - s)/gamma(1 - s),
s, x, (-oo, None))) \
== (x - 1)**(beta - 1)*Heaviside(x - 1)
assert simp_pows(IMT(gamma(s)*gamma(rho - s)/gamma(rho), s, x, (0, None))) \
== (1/(x + 1))**rho
assert simp_pows(IMT(d**c*d**(s - 1)*sin(pi*c)
*gamma(s)*gamma(s + c)*gamma(1 - s)*gamma(1 - s - c)/pi,
s, x, (Max(-re(c), 0), Min(1 - re(c), 1)))) \
== (x**c - d**c)/(x - d)
assert simplify(IMT(1/sqrt(pi)*(-c/2)*gamma(s)*gamma((1 - c)/2 - s)
*gamma(-c/2 - s)/gamma(1 - c - s),
s, x, (0, -re(c)/2))) == \
(1 + sqrt(x + 1))**c
assert simplify(IMT(2**(a + 2*s)*b**(a + 2*s - 1)*gamma(s)*gamma(1 - a - 2*s)
/gamma(1 - a - s), s, x, (0, (-re(a) + 1)/2))) == \
b**(a - 1)*(sqrt(1 + x/b**2) + 1)**(a - 1)*(b**2*sqrt(1 + x/b**2) +
b**2 + x)/(b**2 + x)
assert simplify(IMT(-2**(c + 2*s)*c*b**(c + 2*s)*gamma(s)*gamma(-c - 2*s)
/ gamma(-c - s + 1), s, x, (0, -re(c)/2))) == \
b**c*(sqrt(1 + x/b**2) + 1)**c
# Section 8.4.5
assert IMT(24 / s**5, s, x, (0, oo)) == log(x)**4 * Heaviside(1 - x)
assert expand(IMT(6/s**4, s, x, (-oo, 0)), force=True) == \
log(x)**3*Heaviside(x - 1)
assert IMT(pi / (s * sin(pi * s)), s, x, (-1, 0)) == log(x + 1)
assert IMT(pi / (s * sin(pi * s / 2)), s, x, (-2, 0)) == log(x**2 + 1)
assert IMT(pi / (s * sin(2 * pi * s)), s, x,
(-S(1) / 2, 0)) == log(sqrt(x) + 1)
assert IMT(pi / (s * sin(pi * s)), s, x, (0, 1)) == log(1 + 1 / x)
# TODO
def mysimp(expr):
from sympy import expand, logcombine, powsimp
return expand(powsimp(logcombine(expr, force=True),
force=True,
deep=True),
force=True).replace(exp_polar, exp)
assert mysimp(mysimp(IMT(pi / (s * tan(pi * s)), s, x, (-1, 0)))) in [
log(1 - x) * Heaviside(1 - x) + log(x - 1) * Heaviside(x - 1),
log(x) * Heaviside(x - 1) + log(1 - 1 / x) * Heaviside(x - 1) +
log(-x + 1) * Heaviside(-x + 1)
]
# test passing cot
assert mysimp(IMT(pi * cot(pi * s) / s, s, x, (0, 1))) in [
log(1 / x - 1) * Heaviside(1 - x) + log(1 - 1 / x) * Heaviside(x - 1),
-log(x) * Heaviside(-x + 1) + log(1 - 1 / x) * Heaviside(x - 1) +
log(-x + 1) * Heaviside(-x + 1),
]
# 8.4.14
assert IMT(-gamma(s + S(1)/2)/(sqrt(pi)*s), s, x, (-S(1)/2, 0)) == \
erf(sqrt(x))
# 8.4.19
assert simplify(IMT(gamma(a/2 + s)/gamma(a/2 - s + 1), s, x, (-re(a)/2, S(3)/4))) \
== besselj(a, 2*sqrt(x))
assert simplify(IMT(2**a*gamma(S(1)/2 - 2*s)*gamma(s + (a + 1)/2)
/ (gamma(1 - s - a/2)*gamma(1 - 2*s + a)),
s, x, (-(re(a) + 1)/2, S(1)/4))) == \
sin(sqrt(x))*besselj(a, sqrt(x))
assert simplify(IMT(2**a*gamma(a/2 + s)*gamma(S(1)/2 - 2*s)
/ (gamma(S(1)/2 - s - a/2)*gamma(1 - 2*s + a)),
s, x, (-re(a)/2, S(1)/4))) == \
cos(sqrt(x))*besselj(a, sqrt(x))
# TODO this comes out as an amazing mess, but simplifies nicely
assert simplify(IMT(gamma(a + s)*gamma(S(1)/2 - s)
/ (sqrt(pi)*gamma(1 - s)*gamma(1 + a - s)),
s, x, (-re(a), S(1)/2))) == \
besselj(a, sqrt(x))**2
assert simplify(IMT(gamma(s)*gamma(S(1)/2 - s)
/ (sqrt(pi)*gamma(1 - s - a)*gamma(1 + a - s)),
s, x, (0, S(1)/2))) == \
besselj(-a, sqrt(x))*besselj(a, sqrt(x))
assert simplify(IMT(4**s*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)),
s, x, (-(re(a) + re(b))/2, S(1)/2))) == \
besselj(a, sqrt(x))*besselj(b, sqrt(x))
# Section 8.4.20
# TODO this can be further simplified!
assert simplify(IMT(-2**(2*s)*cos(pi*a/2 - pi*b/2 + pi*s)*gamma(-2*s + 1) *
gamma(a/2 - b/2 + s)*gamma(a/2 + b/2 + s) /
(pi*gamma(a/2 - b/2 - s + 1)*gamma(a/2 + b/2 - s + 1)),
s, x,
(Max(-re(a)/2 - re(b)/2, -re(a)/2 + re(b)/2), S(1)/2))) == \
besselj(a, sqrt(x))*-(besselj(-b, sqrt(x)) -
besselj(b, sqrt(x))*cos(pi*b))/sin(pi*b)
# TODO more
# for coverage
assert IMT(pi / cos(pi * s), s, x, (0, S(1) / 2)) == sqrt(x) / (x + 1)
def test_rewrite():
from sympy import polar_lift, exp, I
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_bessel():
from sympy import besselj, besseli
assert simplify(integrate(besselj(a, z)*besselj(b, z)/z, (z, 0, oo),
meijerg=True, conds='none')) == \
2*sin(pi*(a/2 - b/2))/(pi*(a - b)*(a + b))
assert simplify(
integrate(besselj(a, z) * besselj(a, z) / z, (z, 0, oo),
meijerg=True,
conds='none')) == 1 / (2 * a)
# TODO more orthogonality integrals
assert simplify(integrate(sin(z*x)*(x**2 - 1)**(-(y + S(1)/2)),
(x, 1, oo), meijerg=True, conds='none')
*2/((z/2)**y*sqrt(pi)*gamma(S(1)/2 - y))) == \
besselj(y, z)
# Werner Rosenheinrich
# SOME INDEFINITE INTEGRALS OF BESSEL FUNCTIONS
assert integrate(x * besselj(0, x), x, meijerg=True) == x * besselj(1, x)
assert integrate(x * besseli(0, x), x, meijerg=True) == x * besseli(1, x)
# TODO can do higher powers, but come out as high order ... should they be
# reduced to order 0, 1?
assert integrate(besselj(1, x), x, meijerg=True) == -besselj(0, x)
assert integrate(besselj(1, x)**2/x, x, meijerg=True) == \
-(besselj(0, x)**2 + besselj(1, x)**2)/2
# TODO more besseli when tables are extended or recursive mellin works
assert integrate(besselj(0, x)**2/x**2, x, meijerg=True) == \
-2*x*besselj(0, x)**2 - 2*x*besselj(1, x)**2 \
+ 2*besselj(0, x)*besselj(1, x) - besselj(0, x)**2/x
assert integrate(besselj(0, x)*besselj(1, x), x, meijerg=True) == \
-besselj(0, x)**2/2
assert integrate(x**2*besselj(0, x)*besselj(1, x), x, meijerg=True) == \
x**2*besselj(1, x)**2/2
assert integrate(besselj(0, x)*besselj(1, x)/x, x, meijerg=True) == \
(x*besselj(0, x)**2 + x*besselj(1, x)**2 -
besselj(0, x)*besselj(1, x))
# TODO how does besselj(0, a*x)*besselj(0, b*x) work?
# TODO how does besselj(0, x)**2*besselj(1, x)**2 work?
# TODO sin(x)*besselj(0, x) etc come out a mess
# TODO can x*log(x)*besselj(0, x) be done?
# TODO how does besselj(1, x)*besselj(0, x+a) work?
# TODO more indefinite integrals when struve functions etc are implemented
# test a substitution
assert integrate(besselj(1, x**2)*x, x, meijerg=True) == \
-besselj(0, x**2)/2
def test_expand():
assert expand_func(besselj(S(1)/2, z)) == sqrt(2)*sin(z)/(sqrt(pi)*sqrt(z))
assert expand_func(
bessely(S(1)/2, z)) == -sqrt(2)*cos(z)/(sqrt(pi)*sqrt(z))
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Special math functions
======================
Common special functions to be used across Sympy implemented models
"""
from sympy import besselj, bessely, legendre, I, sqrt, pi
from sympy import symbols
p, m, v, n, z = symbols('p m v n z')
# spherical Bessel function
sph_bessel1 = besselj(n + 1 / 2, z) * sqrt(pi / (2 * z))
# sphericl Neumann function
sph_bessel2 = bessely(n + 1 / 2, z) * sqrt(pi / (2 * z))
# spherical Hankel function of the second kind
sph_hankel2 = sph_bessel1 - I * sph_bessel2
h2_nz = sph_bessel1 - I * sph_bessel2 # more compact notation.
# This function can actuall be replaced by the inbuilt 'assoc_legendre' with varying mileage
# upon lambdification
# pmvz version of legendre function (Appendix II of Beranek & Mello 2012, eqn. 63)
# this is the equivalent of Latex: P^{m}_{v}(z)
legendre_mvz = ((-1)**m) * ((1 - z**2)**(m / 2)) * legendre(v, z).diff((z, m))
def test_laplace_transform():
from sympy import fresnels, fresnelc, DiracDelta
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), 1)
# 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 * s) + EulerGamma) / s / -1, 0, True)
assert LT(erf(t), t, s) == (erfc(s / 2) * 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) == (b / (b**2 + (a + s)**2), -a, True)
assert LT(exp(-a*t)*cos(b*t), t, s) == \
((a + s)/(b**2 + (a + s)**2), -a, True)
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),
]
# DiracDelta function: standard cases
assert LT(DiracDelta(t), t, s) == (1, -oo, True)
assert LT(DiracDelta(a * t), t, s) == (1 / a, -oo, True)
assert LT(DiracDelta(t / 42), t, s) == (42, -oo, True)
assert LT(DiracDelta(t + 42), t, s) == (0, -oo, True)
assert LT(DiracDelta(t)+DiracDelta(t-42), t, s) == \
(1 + exp(-42*s), -oo, True)
assert LT(DiracDelta(t) - a * exp(-a * t), t,
s) == (-a / (a + s) + 1, 0, True)
assert LT(exp(-t)*(DiracDelta(t)+DiracDelta(t-42)), t, s) == \
(exp(-42*s - 42) + 1, -oo, True)
# Collection of cases that cannot be fully evaluated and/or would catch
# some common implementation errors
assert LT(DiracDelta(t**2), t,
s) == LaplaceTransform(DiracDelta(t**2), t, s)
assert LT(DiracDelta(t**2 - 1), t, s) == (exp(-s) / 2, -oo, True)
assert LT(DiracDelta(t*(1 - t)), t, s) == \
LaplaceTransform(DiracDelta(-t**2 + t), t, s)
assert LT((DiracDelta(t) + 1)*(DiracDelta(t - 1) + 1), t, s) == \
(LaplaceTransform(DiracDelta(t)*DiracDelta(t - 1), t, s) + \
1 + exp(-s) + 1/s, 0, True)
assert LT(DiracDelta(2*t - 2*exp(a)), t, s) == \
(exp(-s*exp(a))/2, -oo, True)
# Fresnel functions
assert laplace_transform(fresnels(t), t, s) == \
((-sin(s**2/(2*pi))*fresnels(s/pi) + sin(s**2/(2*pi))/2 -
cos(s**2/(2*pi))*fresnelc(s/pi) + cos(s**2/(2*pi))/2)/s, 0, True)
assert laplace_transform(
fresnelc(t), t,
s) == (((2 * sin(s**2 / (2 * pi)) * fresnelc(s / pi) -
2 * cos(s**2 / (2 * pi)) * fresnels(s / pi) +
sqrt(2) * cos(s**2 / (2 * pi) + pi / 4)) / (2 * s), 0, True))
# What is this testing:
Ne(1 / s, 1) & (0 < cos(Abs(periodic_argument(s, oo))) * Abs(s) - 1)
Mt = Matrix([[exp(t), t * exp(-t)], [t * exp(-t), exp(t)]])
Ms = Matrix([[1 / (s - 1), (s + 1)**(-2)], [(s + 1)**(-2), 1 / (s - 1)]])
# The default behaviour for Laplace tranform of a Matrix returns a Matrix
# of Tuples and is deprecated:
with warns_deprecated_sympy():
Ms_conds = Matrix([[(1 / (s - 1), 1, s > 1), ((s + 1)**(-2), 0, True)],
[((s + 1)**(-2), 0, True),
(1 / (s - 1), 1, s > 1)]])
with warns_deprecated_sympy():
assert LT(Mt, t, s) == Ms_conds
# The new behavior is to return a tuple of a Matrix and the convergence
# conditions for the matrix as a whole:
assert LT(Mt, t, s, legacy_matrix=False) == (Ms, 1, s > 1)
# With noconds=True the transformed matrix is returned without conditions
# either way:
assert LT(Mt, t, s, noconds=True) == Ms
assert LT(Mt, t, s, legacy_matrix=False, noconds=True) == Ms
def test_inverse_laplace_transform():
from sympy import simplify, factor_terms, DiracDelta
ILT = inverse_laplace_transform
a, b, c, = symbols('a b c', positive=True)
t = symbols('t')
def simp_hyp(expr):
return factor_terms(expand_mul(expr)).rewrite(sin)
assert ILT(1, s, t) == DiracDelta(t)
assert ILT(1 / s, s, t) == Heaviside(t)
assert ILT(a / (a + s), s, t) == a * exp(-a * t) * Heaviside(t)
assert ILT(s / (a + s), s,
t) == -a * exp(-a * t) * Heaviside(t) + DiracDelta(t)
assert ILT((a + s)**(-2), s, t) == t * exp(-a * t) * Heaviside(t)
assert ILT((a + s)**(-5), s, t) == t**4 * exp(-a * t) * Heaviside(t) / 24
assert ILT(a / (a**2 + s**2), s, t) == sin(a * t) * Heaviside(t)
assert ILT(s / (s**2 + a**2), s, t) == cos(a * t) * Heaviside(t)
assert ILT(b / (b**2 + (a + s)**2), s,
t) == exp(-a * t) * sin(b * t) * Heaviside(t)
assert ILT(b*s/(b**2 + (a + s)**2), s, t) +\
(a*sin(b*t) - b*cos(b*t))*exp(-a*t)*Heaviside(t) == 0
assert ILT(exp(-a * s) / s, s, t) == Heaviside(-a + t)
assert ILT(exp(-a * s) / (b + s), s,
t) == exp(b * (a - t)) * Heaviside(-a + t)
assert ILT((b + s)/(a**2 + (b + s)**2), s, t) == \
exp(-b*t)*cos(a*t)*Heaviside(t)
assert ILT(exp(-a*s)/s**b, s, t) == \
(-a + t)**(b - 1)*Heaviside(-a + t)/gamma(b)
assert ILT(exp(-a*s)/sqrt(s**2 + 1), s, t) == \
Heaviside(-a + t)*besselj(0, a - t)
assert ILT(1 / (s * sqrt(s + 1)), s, t) == Heaviside(t) * erf(sqrt(t))
assert ILT(1 / (s**2 * (s**2 + 1)), s, t) == (t - sin(t)) * Heaviside(t)
assert ILT(s**2 / (s**2 + 1), s,
t) == -sin(t) * Heaviside(t) + DiracDelta(t)
assert ILT(1 - 1 / (s**2 + 1), s,
t) == -sin(t) * Heaviside(t) + DiracDelta(t)
assert ILT(1 / s**2, s, t) == t * Heaviside(t)
assert ILT(1 / s**5, s, t) == t**4 * Heaviside(t) / 24
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)
# 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)]])
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
def test_besselj_leading_term():
assert besselj(0, x).as_leading_term(x) == 1
assert besselj(1, sin(x)).as_leading_term(x) == x / 2
assert besselj(1, 2 * sqrt(x)).as_leading_term(x) == sqrt(x)
f = HDF5File(mpi_comm_world(),
'precomputed/precomputed_' + meshName + note + '.hdf5', 'w')
# precomputation of Bessel functions=============================================================================
temp = toc()
coefs_r_prec = [] # these will be functions in PS
coefs_i_prec = [] # these will be functions in PS
c0ex = Expression("(maxc-c*(x[0]*x[0]+x[1]*x[1]))",
maxc=Constant(coef_par_max),
c=Constant(coef_par))
f.write(interpolate(c0ex, PS), "parab")
# plot(interpolate(c0ex, PS), interactive=True, title='Parab')
for i in range(8):
r = symbols('r')
besRe = re(coefs_mult[i] *
(coefs_bes_mult[i] * besselj(0, r * coefs_bes[i]) + 1))
besIm = im(coefs_mult[i] *
(coefs_bes_mult[i] * besselj(0, r * coefs_bes[i]) + 1))
besRe_lambda = lambdify(r, besRe, ['numpy', {'besselj': jv}])
besIm_lambda = lambdify(r, besIm, ['numpy', {'besselj': jv}])
class PartialReSolution(Expression):
def eval(self, value, x):
rad = float(sqrt(x[0] * x[0] + x[1] * x[1]))
# conversion to float needed, u_lambda (and near) cannot use sympy Float as input
value[0] = 0 if near(rad, R) else besRe_lambda(
rad) # do not evaluate on boundaries, it's 0
# print(value) gives reasonable values
expr = PartialReSolution()
print('i = ' + str(i) + ' interpolating real part')
def dispeq_gyrotropic_cylindersArrayFull(N_max, w_01, a_0, ee, cylXY, k, p, EE, GG, HH, c, ):
m = list(range(-N_max, N_max + 1, 1))
if N_max == 0:
m = 0
nu = m
w = w_01
k0 = w / c
q = cmath.sqrt(1 - p **2)
# q = q * (2 * ((q.imag) <= 0) - 1)
Q = k0 * a_0 * q
# вычисляем элементы матрицы рассеяния для внутренней области цилиндра
mainq = EE ** 2 - GG ** 2 + EE * HH - (HH + EE) * p ** 2
F=cmath.sqrt(EE*GG**2*HH*(GG**2-(HH-EE)**2))
Pb=cmath.sqrt(EE-(HH+EE)*GG**2/(HH-EE)**2-2*F/(HH-EE)**2)
Pc=cmath.sqrt(EE-(HH+EE)*GG**2/(HH-EE)**2+2*F/(HH-EE)**2)
#radq = math.sqrt((HH - EE) ** 2 * p **4 + 2 * ((GG ** 2)*(HH + EE) - EE * (HH - EE) **2) * p **2 +(EE ** 2 - GG ** 2 - EE * HH) ** 2)
radq = -(HH-EE)*cmath.sqrt((p**2-Pb**2)*(p**2-Pc**2))
q1 = cmath.sqrt(0.5 * (mainq - radq) / EE)
q2 = cmath.sqrt(0.5 * (mainq + radq) / EE)
n1 = -(EE / (p * GG) ) * (p ** 2 + q1 ** 2 + (GG ** 2)/EE - EE)
n2 = -(EE / (p * GG) ) * (p ** 2 + q2 ** 2 + (GG ** 2)/EE - EE)
alp1 = -1 + (p ** 2 + q1 ** 2 - EE) / GG
alp2 = -1 + (p ** 2 + q2 ** 2 - EE) / GG
bet1 = 1 + p / n1
bet2 = 1 + p / n2
#что делать с Q она мнимая, брать действительную или мнимую часть?
Q1 = (q1 * a_0) * k0
Q2 = (q2 * a_0) * k0
mMax = 2 * N_max + 1
JM = np.zeros(((3, 31)), dtype=np.complex)
n=0
for per in range(-N_max,N_max+1,1):
JM[n][0] = besselj(per + 1, Q1) #JM1
JM[n][1] = besselj(per + 1, Q2) #JM2
JM[n][2]= besselj(per, Q1) #Jm1
JM[n][3]= besselj(per, Q2) #Jm2
JM[n][4]= JM[n][per + 2] / Q1 #Jm1_Q1
JM[n][5]= JM[n][per + 3]/ Q2 #Jm2_Q2
JM[n][6]= (((1j / HH) * n1) * q1) * JM[n][per + 2] #Ez1
JM[n][7] = (((1j / HH) * n2) * q2) * JM[n][per + 3] #Ez2
JM[n][8] = 1j * (JM[n][per] + (alp1 * per) * JM[n][per + 4]) #Ephi1
JM[n][9]= 1j * (JM[n][per+1] + (alp2 * per) *JM[n][per + 5] ) #Ephi2
JM[n][10]= - q1 * JM[n][per + 2] #Hz1
JM[n][11]= - q2 * JM[n][per + 3] #Hz2
JM[n][12] = - n1 * (JM[n][per] - (bet1 * per) * JM[n][per + 4]) #Hphi1
JM[n][13]= - n2 * (JM[n][per+1] - (bet2 * per) * JM[n][per + 5]) #Hphi2
# вычисляем элементы матрицы рассеяния для внешней области цилиндра
JM[n][14] = hankel2(per, Q) #H2m
JM[n][15]= -(JM[n][per + 14]/ Q)* per + hankel2(per + 1, Q) #dH2m
#Jm_out = besselj(m, Q)
#dJm_out = Jm_out * m / Q - besselj(m + 1, Q)
JM[n][16] =-1j * q * JM[n][per + 14] #Ez_sct
JM[n][17]= q * JM[n][per + 14] #Hz_sct
A = 1 / (k0 * (1 - p ^ 2))
JM[n][18] = -1j*q * (A * ((p * (per / a_0)) * JM[n][per + 14])) #Ephi_sctE
JM[n][19]= 1j*q * (A * (k0 * q * JM[n][per + 15])) #Ephi_sctH
JM[n][20]= q * (A * ((p * (per / a_0)) * JM[n][per + 14])) #Hphi_sctH
JM[n][21] = -q * (A * (k0 * q * JM[n][per + 15])) #Hphi_sctE
n = n + 1
matrixGS = np.zeros(((mMax*4*2, mMax*4*2)), dtype=np.complex)
for jj in range(0, 2):
for jm in range(1, 4, 1):
for ll in range(0, 2):
for jnu in range(1, 4, 1):
jmmm = (jm - 1) * 4+1
jnunu = (jnu - 1) * 4+1
# спросить про проход ведь будет совпадение номеров
if jj == ll:
if jm == jnu:
matrixGS[jmmm + jj * 4 * mMax, jnunu + ll * 4 * mMax] = JM[jm + 1][6] # Ez1
matrixGS[jmmm + jj * 4 * mMax, jnunu + ll * 4 * mMax + 1] = JM[jm + 1][7] # Ez2(jm)
matrixGS[jmmm + jj * 4 * mMax, jnunu + ll * 4 * mMax + 2] = JM[jm + 1][16] # Ez_sct(jm)
matrixGS[jmmm + jj * 4 * mMax, jnunu + ll * 4 * mMax + 3] = 0
matrixGS[jmmm + jj * 4 * mMax + 1, jnunu + ll * 4 * mMax] = JM[jm + 1][10] # Hz1
matrixGS[jmmm + jj * 4 * mMax + 1, jnunu + ll * 4 * mMax + 1] = JM[jm + 1][11] # Hz2
matrixGS[jmmm + jj * 4 * mMax + 1, jnunu + ll * 4 * mMax + 2] = 0
matrixGS[jmmm + jj * 4 * mMax + 1, jnunu + ll * 4 * mMax + 3] = - JM[jm + 1][17] # -Hz_sct
matrixGS[jmmm + jj * 4 * mMax + 2, jnunu + ll * 4 * mMax] = JM[jm + 1][8] # Ephi1
matrixGS[jmmm + jj * 4 * mMax + 2, jnunu + ll * 4 * mMax + 1] = JM[jm + 1][9] # Ephi2
matrixGS[jmmm + jj * 4 * mMax + 2, jnunu + ll * 4 * mMax + 2] = -JM[jm + 1][18] # -Ephi_sctE
matrixGS[jmmm + jj * 4 * mMax + 2, jnunu + ll * 4 * mMax + 3] = -JM[jm + 1][19] # -Ephi_sctH
matrixGS[jmmm + jj * 4 * mMax + 3, jnunu + ll * 4 * mMax] = JM[jm + 1][12] # Hphi1
matrixGS[jmmm + jj * 4 * mMax + 3, jnunu + ll * 4 * mMax + 1] = JM[jm + 1][13] # Hphi2
matrixGS[jmmm + jj * 4 * mMax + 3, jnunu + ll * 4 * mMax + 2] = -JM[jm + 1][21] # -Hphi_sctE
matrixGS[jmmm + jj * 4 * mMax + 3, jnunu + ll * 4 * mMax + 3] = -JM[jm + 1][20] # -Hphi_sctH
else:
Ljl = float(math.sqrt((cylXY[jj , 0] - cylXY[ll , 0]) ** 2 + (cylXY[jj , 1] - cylXY[ll , 1]) ** 2))
thetaIJ =float(math.atan(abs(cylXY[jj , 1] - cylXY[ll , 1]) / abs(cylXY[jj , 0] - cylXY[ll , 0])))
if ((cylXY[jj , 0] - cylXY[ll , 0]) <= 0 and (cylXY[jj , 1] - cylXY[ll , 1]) > 0):
thetaIJ = cmath.pi - thetaIJ
elif ((cylXY[jj , 0] - cylXY[ll , 0]) <= 0 and (cylXY[jj, 1] - cylXY[ll , 1]) <= 0):
thetaIJ = cmath.pi + thetaIJ
elif ((cylXY[jj , 1] - cylXY[ll , 1]) <= 0 and (cylXY[jj, 0] - cylXY[ll , 0]) > 0):
thetaIJ = 2 * cmath.pi - thetaIJ
JM[jnu - 1][22] = -cmath.exp(-1j * (nu[jnu - 1] - m[jm - 1]) * thetaIJ) ** hankel2((m[jm - 1] - nu[jnu - 1]), k0 * q * Ljl)
JM[jnu - 1][23] = besselj(m[jnu - 1], Q) # Jm_out
JM[jnu - 1][24] = -JM[jnu - 1][23] * m[jnu - 1] / Q + besselj(m[jnu - 1] + 1, Q) # dJm_out
# спросить почему они одинаковые?
JM[jnu - 1][25] = JM[jnu - 1][22] * JM[jnu - 1][23] # Ez_inc
JM[jnu - 1][26] = JM[jnu - 1][22] * JM[jnu - 1][23] # Hz_inc
A = 1 / (k0 * (1 - p ** 2))
JM[jnu - 1][27] = - JM[jnu - 1][22] * (
A * ((p * (m[jnu - 1] / a_0)) * JM[jnu - 1][23])) # Ephi_incE
JM[jnu - 1][28] = - JM[jnu - 1][22] * (A * (- 1j * k0 * q * JM[jnu - 1][24])) # Ephi_incH
JM[jnu - 1][29] = - JM[jnu - 1][22] * (A * (1j * k0 * q * JM[jnu - 1][24])) # Hphi_incE
JM[jnu - 1][30] = -JM[jnu - 1][22] * (A * ((p * (m[jnu - 1] / a_0)) * JM[jnu - 1][23]))
matrixGS[jmmm + jj * 4 * mMax, jnunu + ll * 4 * mMax] = 0
matrixGS[jmmm + jj * 4 * mMax, jnunu + ll * 4 * mMax + 1] = 0
matrixGS[jmmm + jj * 4 * mMax, jnunu + ll * 4 * mMax + 2] = JM[jm + 1][25] # Ez_inc
matrixGS[jmmm + jj * 4 * mMax, jnunu + ll * 4 * mMax + 3] = 0
matrixGS[jmmm + jj * 4 * mMax + 1, jnunu + ll * 4 * mMax] = 0
matrixGS[jmmm + jj * 4 * mMax + 1, jnunu + ll * 4 * mMax + 1] = 0
matrixGS[jmmm + jj * 4 * mMax + 1, jnunu + ll * 4 * mMax + 2] = 0
matrixGS[jmmm + jj * 4 * mMax + 1, jnunu + ll * 4 * mMax + 3] = JM[jm + 1][25] # Hz_inc
matrixGS[jmmm + jj * 4 * mMax + 2, jnunu + ll * 4 * mMax] = 0
matrixGS[jmmm + jj * 4 * mMax + 2, jnunu + ll * 4 * mMax + 1] = 0
matrixGS[jmmm + jj * 4 * mMax + 2, jnunu + ll * 4 * mMax + 2] = JM[jm + 1][ 27] # Ephi_incE
matrixGS[jmmm + jj * 4 * mMax + 2, jnunu + ll * 4 * mMax + 3] = JM[jm + 1][28] # Ephi_incH
matrixGS[jmmm + jj * 4 * mMax + 3, jnunu + ll * 4 * mMax] = 0
matrixGS[jmmm + jj * 4 * mMax + 3, jnunu + ll * 4 * mMax + 1] = 0
matrixGS[jmmm + jj * 4 * mMax + 3, jnunu + ll * 4 * mMax + 2] = JM[jm + 1][29] # Hphi_incE
matrixGS[jmmm + jj * 4 * mMax + 3, jnunu + ll * 4 * mMax + 3] = JM[jm + 1][30] # Hphi_incH
return abs(np.linalg.det(matrixGS))
if __name__ == "__main__":
alpha = float(input("\nВведите отношение масс шарика и струны: "))
# plot_function(besselj(0, 2 * sqrt(alpha + 1) * x) * (sqrt(alpha) * x * bessely(0, 2 * sqrt(alpha) * x) - bessely(1, 2 * sqrt(alpha) * x)) - bessely(0, 2 * sqrt(alpha + 1) * x) * (sqrt(alpha) * x * besselj(0, 2 * sqrt(alpha) * x) - besselj(1, 2 * sqrt(alpha) * x)), 0, 8)
while True:
left = float(input("\nВведите левую границу отрезка: "))
right = float(input("Введите правую границу отрезка: "))
init_x = float(input("Введите начальное приближение: "))
print("Для метода половинного деления задан отрезок [" + str(left) +
"; " + str(right) + "]")
print("Для гибридного метода задано начальное приближение: " +
str(init_x))
if init_x == left or init_x == right:
print("Начальное приближение совпадает с одним из концов отрезка")
else:
print(
"Начальное приближение не совпадает ни с одним из концов отрезка"
)
find_solve_with_secant_method(
besselj(0, 2 * sqrt(alpha + 1) * x) *
(sqrt(alpha) * x * bessely(0, 2 * sqrt(alpha) * x) -
bessely(1, 2 * sqrt(alpha) * x)) -
bessely(0, 2 * sqrt(alpha + 1) * x) *
(sqrt(alpha) * x * besselj(0, 2 * sqrt(alpha) * x) -
besselj(1, 2 * sqrt(alpha) * x)), left, right, 10**(-3))
# find_solve_with_hybrid_method(besselj(0, 2 * sqrt(alpha + 1) * x) * (sqrt(alpha) * x * bessely(0, 2 * sqrt(alpha) * x) - bessely(1, 2 * sqrt(alpha) * x)) - bessely(0, 2 * sqrt(alpha + 1) * x) * (sqrt(alpha) * x * besselj(0, 2 * sqrt(alpha) * x) - besselj(1, 2 * sqrt(alpha) * x)), left, right, init_x, 10 ** (-3))
progress = int(
input("Для продолжения нажмите введите 1, для завершения 0: "))
if progress == 0:
break
def test_expand():
assert expand_func(besselj(S(1) / 2,
z)) == sqrt(2) * sin(z) / (sqrt(pi) * sqrt(z))
assert expand_func(bessely(S(1) / 2,
z)) == -sqrt(2) * cos(z) / (sqrt(pi) * sqrt(z))
def test_rewrite():
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)
def test_expand():
from sympy import besselsimp, Symbol, exp, exp_polar, I
assert expand_func(besselj(
S.Half, z).rewrite(jn)) == sqrt(2) * sin(z) / (sqrt(pi) * sqrt(z))
assert expand_func(bessely(
S.Half, z).rewrite(yn)) == -sqrt(2) * cos(z) / (sqrt(pi) * sqrt(z))
# XXX: teach sin/cos to work around arguments like
# x*exp_polar(I*pi*n/2). Then change besselsimp -> expand_func
assert besselsimp(besselj(S.Half,
z)) == sqrt(2) * sin(z) / (sqrt(pi) * sqrt(z))
assert besselsimp(besselj(Rational(-1, 2),
z)) == sqrt(2) * cos(z) / (sqrt(pi) * sqrt(z))
assert besselsimp(besselj(Rational(
5, 2), z)) == -sqrt(2) * (z**2 * sin(z) + 3 * z * cos(z) -
3 * sin(z)) / (sqrt(pi) * z**Rational(5, 2))
assert besselsimp(besselj(Rational(
-5, 2), z)) == -sqrt(2) * (z**2 * cos(z) - 3 * z * sin(z) -
3 * cos(z)) / (sqrt(pi) * z**Rational(5, 2))
assert besselsimp(bessely(S.Half,
z)) == -(sqrt(2) * cos(z)) / (sqrt(pi) * sqrt(z))
assert besselsimp(bessely(Rational(-1, 2),
z)) == sqrt(2) * sin(z) / (sqrt(pi) * sqrt(z))
assert besselsimp(bessely(Rational(
5, 2), z)) == sqrt(2) * (z**2 * cos(z) - 3 * z * sin(z) -
3 * cos(z)) / (sqrt(pi) * z**Rational(5, 2))
assert besselsimp(bessely(Rational(
-5, 2), z)) == -sqrt(2) * (z**2 * sin(z) + 3 * z * cos(z) -
3 * sin(z)) / (sqrt(pi) * z**Rational(5, 2))
assert besselsimp(besseli(S.Half,
z)) == sqrt(2) * sinh(z) / (sqrt(pi) * sqrt(z))
assert besselsimp(besseli(Rational(-1, 2),
z)) == sqrt(2) * cosh(z) / (sqrt(pi) * sqrt(z))
assert besselsimp(besseli(Rational(
5, 2), z)) == sqrt(2) * (z**2 * sinh(z) - 3 * z * cosh(z) +
3 * sinh(z)) / (sqrt(pi) * z**Rational(5, 2))
assert besselsimp(besseli(Rational(
-5, 2), z)) == sqrt(2) * (z**2 * cosh(z) - 3 * z * sinh(z) +
3 * cosh(z)) / (sqrt(pi) * z**Rational(5, 2))
assert (besselsimp(besselk(S.Half, z)) == besselsimp(
besselk(Rational(-1, 2), z)) == sqrt(pi) * exp(-z) /
(sqrt(2) * sqrt(z)))
assert (besselsimp(besselk(Rational(5, 2), z)) == besselsimp(
besselk(Rational(-5, 2), z)) == sqrt(2) * sqrt(pi) *
(z**2 + 3 * z + 3) * exp(-z) / (2 * z**Rational(5, 2)))
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,
)
n = Symbol("n", integer=True, positive=True)
assert (expand_func(besseli(n + 2, z)) == besseli(n, z) + (-2 * n - 2) *
(-2 * n * besseli(n, z) / z + besseli(n - 1, z)) / z)
assert (expand_func(besselj(n + 2, z)) == -besselj(n, z) + (2 * n + 2) *
(2 * n * besselj(n, z) / z - besselj(n - 1, z)) / z)
assert (expand_func(besselk(n + 2, z)) == besselk(n, z) + (2 * n + 2) *
(2 * n * besselk(n, z) / z + besselk(n - 1, z)) / z)
assert (expand_func(bessely(n + 2, z)) == -bessely(n, z) + (2 * n + 2) *
(2 * n * bessely(n, z) / z - bessely(n - 1, z)) / z)
assert expand_func(besseli(
n + S.Half,
z).rewrite(jn)) == (sqrt(2) * sqrt(z) * exp(-I * pi *
(n + S.Half) / 2) *
exp_polar(I * pi / 4) *
jn(n, z * exp_polar(I * pi / 2)) / sqrt(pi))
assert expand_func(besselj(
n + S.Half, z).rewrite(jn)) == sqrt(2) * sqrt(z) * jn(n, z) / sqrt(pi)
r = Symbol("r", real=True)
p = Symbol("p", positive=True)
i = Symbol("i", integer=True)
for besselx in [besselj, bessely, besseli, besselk]:
assert besselx(i, p).is_extended_real is True
assert besselx(i, x).is_extended_real is None
assert besselx(x, z).is_extended_real is None
for besselx in [besselj, besseli]:
assert besselx(i, r).is_extended_real is True
for besselx in [bessely, besselk]:
assert besselx(i, r).is_extended_real is None
def test_bessel_eval():
from sympy import I
assert besselj(-4, z) == besselj(4, z)
assert besselj(-3, z) == -besselj(3, z)
assert bessely(-2, z) == bessely(2, z)
assert bessely(-1, z) == -bessely(1, 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)
def test_inverse_mellin_transform():
from sympy import (sin, simplify, expand_func, powsimp, Max, Min, expand,
powdenest, powsimp, exp_polar)
IMT = inverse_mellin_transform
assert IMT(gamma(s), s, x, (0, oo)) == exp(-x)
assert IMT(gamma(-s), s, x, (-oo, 0)) == exp(-1 / x)
assert IMT(s/(2*s**2 - 2), s, x, (2, oo)) \
== (x**2/2 + S(1)/2)*Heaviside(1 - x)/(2*x)
# test passing "None"
assert IMT(1/(s**2 - 1), s, x, (-1, None)) \
== -x*Heaviside(-x + 1)/2 - Heaviside(x - 1)/(2*x)
assert IMT(1/(s**2 - 1), s, x, (None, 1)) \
== -x*Heaviside(-x + 1)/2 - Heaviside(x - 1)/(2*x)
# test expansion of sums
assert IMT(gamma(s) + gamma(s - 1), s, x, (1, oo)) == (x + 1) * exp(-x) / x
# test factorisation of polys
assert simplify(expand_func(IMT(1/(s**2 + 1), s, exp(-x),
(None, oo))).rewrite(sin)) \
== sin(x)*Heaviside(1 - exp(-x))
# test multiplicative substitution
a, b = symbols('a b', positive=True)
c, d = symbols('c d')
assert IMT(b**(-s / a) * factorial(s / a) / s, s, x,
(0, oo)) == exp(-b * x**a)
assert IMT(factorial(a / b + s / b) / (a + s), s, x,
(-a, oo)) == x**a * exp(-x**b)
from sympy import expand_mul
def simp_pows(expr):
return expand_mul(simplify(powsimp(expr, force=True)),
deep=True).replace(exp_polar, exp) # XXX ?
# Now test the inverses of all direct transforms tested above
# Section 8.4.2
assert IMT(-1 / (nu + s), s, x, (-oo, None)) == x**nu * Heaviside(x - 1)
assert IMT(1 / (nu + s), s, x, (None, oo)) == x**nu * Heaviside(1 - x)
assert simp_pows(IMT(gamma(beta)*gamma(s)/gamma(s + beta), s, x, (0, oo))) \
== (1 - x)**(beta - 1)*Heaviside(1 - x)
assert simp_pows(IMT(gamma(beta)*gamma(1-beta-s)/gamma(1-s),
s, x, (-oo, None))) \
== (x - 1)**(beta - 1)*Heaviside(x - 1)
assert simp_pows(IMT(gamma(s)*gamma(rho-s)/gamma(rho), s, x, (0, None))) \
== (1/(x + 1))**rho
# TODO should this simplify further?
assert simp_pows(IMT(d**c*d**(s-1)*sin(pi*c) \
*gamma(s)*gamma(s+c)*gamma(1-s)*gamma(1-s-c)/pi,
s, x, (Max(-re(c), 0), Min(1 - re(c), 1)))) \
== d**c*(x/d)**c/(-d + x) - d**c/(-d + x)
# TODO is calling simplify twice a bug?
assert simplify(simplify(IMT(1/sqrt(pi)*(-c/2)*gamma(s)*gamma((1-c)/2 - s) \
*gamma(-c/2-s)/gamma(1-c-s),
s, x, (0, -re(c)/2)))) == \
(1 + sqrt(x + 1))**c
assert simplify(IMT(2**(a + 2*s)*b**(a + 2*s - 1)*gamma(s)*gamma(1 - a - 2*s) \
/gamma(1 - a - s), s, x, (0, (-re(a) + 1)/2))) == \
(b + sqrt(b**2 + x))**(a - 1)*(b**2 + b*sqrt(b**2 + x) + x)/(b**2 + x)
assert simplify(IMT(-2**(c + 2*s)*c*b**(c + 2*s)*gamma(s)*gamma(-c - 2*s) \
/ gamma(-c - s + 1), s, x, (0, -re(c)/2))) == \
(b + sqrt(b**2 + x))**c
# Section 8.4.5
assert IMT(24 / s**5, s, x, (0, oo)) == log(x)**4 * Heaviside(1 - x)
assert expand(IMT(6/s**4, s, x, (-oo, 0)), force=True) == \
log(x)**3*Heaviside(x - 1)
assert IMT(pi / (s * sin(pi * s)), s, x, (-1, 0)) == log(x + 1)
assert IMT(pi / (s * sin(pi * s / 2)), s, x, (-2, 0)) == log(x**2 + 1)
assert IMT(pi / (s * sin(2 * pi * s)), s, x,
(-S(1) / 2, 0)) == log(sqrt(x) + 1)
assert IMT(pi / (s * sin(pi * s)), s, x, (0, 1)) == log(1 + 1 / x)
# TODO
def mysimp(expr):
from sympy import expand, logcombine, powsimp
return expand(powsimp(logcombine(expr, force=True),
force=True,
deep=True),
force=True).replace(exp_polar, exp)
assert mysimp(mysimp(IMT(pi/(s*tan(pi*s)), s, x, (-1, 0)))) == \
log(1-x)*Heaviside(1-x) + log(x-1)*Heaviside(x-1)
assert mysimp(IMT(pi/(s*tan(pi*s)), s, x, (0, 1))) == \
log(1/x - 1)*Heaviside(1-x) + log(1 - 1/x)*Heaviside(x-1)
# 8.4.14
assert IMT(-gamma(s + S(1)/2)/(sqrt(pi)*s), s, x, (-S(1)/2, 0)) == \
erf(sqrt(x))
# 8.4.19
# TODO these come out ugly
def mysimp(expr):
return expand(
unpolarify(simplify(expand(expand_func(expr.rewrite(besselj))))))
assert mysimp(IMT(gamma(a/2 + s)/gamma(a/2 - s + 1), s, x, (-re(a)/2, S(3)/4))) \
== besselj(a, 2*sqrt(x)*polar_lift(-1))*exp(-I*pi*a)
assert mysimp(IMT(2**a*gamma(S(1)/2 - 2*s)*gamma(s + (a + 1)/2) \
/ (gamma(1 - s - a/2)*gamma(1 - 2*s + a)),
s, x, (-(re(a) + 1)/2, S(1)/4))) == \
exp(-I*pi*a)*sin(sqrt(x))*besselj(a, sqrt(x)*polar_lift(-1))
assert mysimp(IMT(2**a*gamma(a/2 + s)*gamma(S(1)/2 - 2*s) \
/ (gamma(S(1)/2 - s - a/2)*gamma(1 - 2*s + a)),
s, x, (-re(a)/2, S(1)/4))) == \
exp(-I*pi*a)*cos(sqrt(x))*besselj(a, sqrt(x)*polar_lift(-1))
# TODO this comes out as an amazing mess, but surprisingly enough mysimp is
# effective ...
assert powsimp(powdenest(mysimp(IMT(gamma(a + s)*gamma(S(1)/2 - s) \
/ (sqrt(pi)*gamma(1 - s)*gamma(1 + a - s)),
s, x, (-re(a), S(1)/2))), polar=True)) == \
exp(-2*I*pi*a)*besselj(a, sqrt(x)*polar_lift(-1))**2
# NOTE the next is indeed an even function of sqrt(x), so the result is
# correct
assert mysimp(IMT(gamma(s)*gamma(S(1)/2 - s) \
/ (sqrt(pi)*gamma(1 - s - a)*gamma(1 + a - s)),
s, x, (0, S(1)/2))) == \
besselj(-a, polar_lift(-1)*sqrt(x))*besselj(a, polar_lift(-1)*sqrt(x))
assert mysimp(IMT(4**s*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)),
s, x, (-(re(a) + re(b))/2, S(1)/2))) == \
exp(-I*pi*a)*exp(-I*pi*b)*besselj(a, sqrt(x)*polar_lift(-1)) \
*besselj(b, sqrt(x)*polar_lift(-1))
# eqn. 13.226
n_B_q_kb = n_B_mka.subs({'m': n, 'n': q, 'ka': kb})
term_13_226 = (conjugate(m_B_p_kb) * n_B_q_kb) / (p + q + 1)
M_mn = Sum(term_13_226, (q, 0, Q), (p, 0, P))
one_Mmn_term = lambdify([a, b, k, m, n, NN], M_mn, 'scipy')
#%%
# eqn. 13.227
b_term = -Sum((conjugate(m_B_p_kb) / (p + 1)) * (a / b)**(2 * p), (p, 0, P))
bterm_func = lambdify([a, b, k, m, NN], b_term, 'scipy')
#%%
# piston in an infinite baffle portion
eq13_252_pt1 = besselj(1, ka * sin(theta)) / (ka * sin(theta))
# piston in a finite open baffle portion
A_n = IndexedBase('A_n')
jj = symbols('jj', integer=True)
pt2_term = A_n[jj] * gamma(jj + 5 / 2) * (
(2 / kb * sin(theta))**(jj + 3 / 2)) * besselj(jj + 3 / 2, kb * sin(theta))
eq13_252_pt2 = (kb / 2) * cos(theta) * Sum(pt2_term, (jj, 0, NN - 1))
# eqn. 13.252
d_theta = eq13_252_pt1 + eq13_252_pt2
d_thetaf = lambdify([k, a, b, theta, A_n, NN], d_theta, 'sympy')
# eqn 13.253
def d_0f(kv, bv, Anmat):
return (1 / 2) * (1 + kv * bv * sum(Anmat))
def test_mellin_transform():
from sympy import Max, Min
MT = mellin_transform
bpos = symbols('b', positive=True)
# 8.4.2
assert MT(x**nu*Heaviside(x - 1), x, s) \
== (1/(-nu - s), (-oo, -re(nu)), True)
assert MT(x**nu*Heaviside(1 - x), x, s) \
== (1/(nu + s), (-re(nu), oo), True)
assert MT((1-x)**(beta - 1)*Heaviside(1-x), x, s) \
== (gamma(beta)*gamma(s)/gamma(beta + s),
(0, oo), re(-beta) < 0)
assert MT((x-1)**(beta - 1)*Heaviside(x-1), x, s) \
== (gamma(beta)*gamma(1 - beta - s)/gamma(1 - s),
(-oo, -re(beta) + 1), re(-beta) < 0)
assert MT(
(1 + x)**(-rho), x,
s) == (gamma(s) * gamma(rho - s) / gamma(rho), (0, re(rho)), True)
# TODO also the conditions should be simplified
assert MT(abs(1-x)**(-rho), x, s) == \
(cos(pi*rho/2 - pi*s)*gamma(s)*gamma(rho-s)/(cos(pi*rho/2)*gamma(rho)),\
(0, re(rho)), And(re(rho) - 1 < 0, re(rho) < 1))
mt = MT((1 - x)**(beta - 1) * Heaviside(1 - x) + a *
(x - 1)**(beta - 1) * Heaviside(x - 1), x, s)
assert mt[1], mt[2] == ((0, -re(beta) + 1), True)
assert MT((x**a-b**a)/(x-b), x, s)[0] == \
pi*b**(a+s-1)*sin(pi*a)/(sin(pi*s)*sin(pi*(a + s)))
assert MT((x**a-bpos**a)/(x-bpos), x, s) == \
(pi*bpos**(a+s-1)*sin(pi*a)/(sin(pi*s)*sin(pi*(a + s))),
(Max(-re(a), 0), Min(1 - re(a), 1)), True)
expr = (sqrt(x + b**2) + b)**a / sqrt(x + b**2)
assert MT(expr.subs(b, bpos), x, s) == \
(2**(a + 2*s)*bpos**(a + 2*s - 1)*gamma(s) \
*gamma(1 - a - 2*s)/gamma(1 - a - s),
(0, -re(a)/2 + S(1)/2), True)
# TODO does not work with bneg, argument wrong. Needs changes to matching.
#assert MT(expr.subs(b, -bpos), x, s) == \
# ((-1)**(a+1)*2**(a + 2*s)*bpos**(a + 2*s - 1)*gamma(a + s) \
# *gamma(1 - a - 2*s)/gamma(1 - s),
# (-re(a), -re(a)/2 + S(1)/2), True)
expr = (sqrt(x + b**2) + b)**a
assert MT(expr.subs(b, bpos), x, s) == \
(-2**(a + 2*s)*a*bpos**(a + 2*s)*gamma(s)*gamma(-a - 2*s)/gamma(-a - s + 1),
(0, -re(a)/2), True)
#assert MT(expr.subs(b, -bpos), x, s) == \
# (2**(a + 2*s)*a*bpos**(a + 2*s)*gamma(-a - 2*s)*gamma(a + s)/gamma(-s + 1),
# (-re(a), -re(a)/2), True)
# Test exponent 1:
#assert MT(expr.subs({b: -bpos, a:1}), x, s) == \
# (-bpos**(2*s + 1)*gamma(s)*gamma(-s - S(1)/2)/(2*sqrt(pi)),
# (-1, -S(1)/2), True)
# 8.4.2
assert MT(exp(-x), x, s) == (gamma(s), (0, oo), True)
assert MT(exp(-1 / x), x, s) == (gamma(-s), (-oo, 0), True)
# 8.4.5
assert MT(log(x)**4 * Heaviside(1 - x), x, s) == (24 / s**5, (0, oo), True)
assert MT(log(x)**3 * Heaviside(x - 1), x, s) == (6 / s**4, (-oo, 0), True)
assert MT(log(x + 1), x, s) == (pi / (s * sin(pi * s)), (-1, 0), True)
assert MT(log(1 / x + 1), x, s) == (pi / (s * sin(pi * s)), (0, 1), True)
assert MT(log(abs(1 - x)), x, s) == (pi / (s * tan(pi * s)), (-1, 0), True)
assert MT(log(abs(1 - 1 / x)), x,
s) == (pi / (s * tan(pi * s)), (0, 1), True)
# TODO we cannot currently do these (needs summation of 3F2(-1))
# this also implies that they cannot be written as a single g-function
# (although this is possible)
mt = MT(log(x) / (x + 1), x, s)
assert mt[1:] == ((0, 1), True)
assert not hyperexpand(mt[0], allow_hyper=True).has(meijerg)
mt = MT(log(x)**2 / (x + 1), x, s)
assert mt[1:] == ((0, 1), True)
assert not hyperexpand(mt[0], allow_hyper=True).has(meijerg)
mt = MT(log(x) / (x + 1)**2, x, s)
assert mt[1:] == ((0, 2), True)
assert not hyperexpand(mt[0], allow_hyper=True).has(meijerg)
# 8.4.14
assert MT(erf(sqrt(x)), x, s) == \
(-gamma(s + S(1)/2)/(sqrt(pi)*s), (-S(1)/2, 0), True)
# 8.4.19
assert MT(besselj(a, 2*sqrt(x)), x, s) == \
(gamma(a/2 + s)/gamma(a/2 - s + 1), (-re(a)/2, S(3)/4), True)
assert MT(sin(sqrt(x))*besselj(a, sqrt(x)), x, s) == \
(2**a*gamma(S(1)/2 - 2*s)*gamma((a+1)/2 + s) \
/ (gamma(1 - s- a/2)*gamma(1 + a - 2*s)),
(-(re(a) + 1)/2, S(1)/4), True)
assert MT(cos(sqrt(x))*besselj(a, sqrt(x)), x, s) == \
(2**a*gamma(a/2 + s)*gamma(S(1)/2 - 2*s)
/ (gamma(S(1)/2 - s - a/2)*gamma(a - 2*s + 1)),
(-re(a)/2, S(1)/4), True)
assert MT(besselj(a, sqrt(x))**2, x, s) == \
(gamma(a + s)*gamma(S(1)/2 - s)
/ (sqrt(pi)*gamma(1 - s)*gamma(1 + a - s)),
(-re(a), S(1)/2), True)
assert MT(besselj(a, sqrt(x))*besselj(-a, sqrt(x)), x, s) == \
(gamma(s)*gamma(S(1)/2 - s)
/ (sqrt(pi)*gamma(1 - a - s)*gamma(1 + a - s)),
(0, S(1)/2), True)
# NOTE: prudnikov gives the strip below as (1/2 - re(a), 1). As far as
# I can see this is wrong (since besselj(z) ~ 1/sqrt(z) for z large)
assert MT(besselj(a - 1, sqrt(x))*besselj(a, sqrt(x)), x, s) == \
(gamma(1-s)*gamma(a + s - S(1)/2)
/ (sqrt(pi)*gamma(S(3)/2 - s)*gamma(a - s + S(1)/2)),
(S(1)/2 - re(a), S(1)/2), True)
assert MT(besselj(a, sqrt(x))*besselj(b, sqrt(x)), x, s) == \
(4**s*gamma(1 - 2*s)*gamma((a+b)/2 + s)
/ (gamma(1 - s + (b-a)/2)*gamma(1 - s + (a-b)/2)
*gamma( 1 - s + (a+b)/2)),
(-(re(a) + re(b))/2, S(1)/2), True)
assert MT(besselj(a, sqrt(x))**2 + besselj(-a, sqrt(x))**2, x, s)[1:] == \
((Max(re(a), -re(a)), S(1)/2), True)
# Section 8.4.20
assert MT(bessely(a, 2*sqrt(x)), x, s) == \
(-cos(pi*a/2 - pi*s)*gamma(s - a/2)*gamma(s + a/2)/pi,
(Max(-re(a)/2, re(a)/2), S(3)/4), True)
assert MT(sin(sqrt(x))*bessely(a, sqrt(x)), x, s) == \
(-4**s*sin(pi*a/2 - pi*s)*gamma(S(1)/2 - 2*s)
* gamma((1-a)/2 + s)*gamma((1+a)/2 + s)
/ (sqrt(pi)*gamma(1 - s - a/2)*gamma(1 - s + a/2)),
(Max(-(re(a) + 1)/2, (re(a) - 1)/2), S(1)/4), True)
assert MT(cos(sqrt(x))*bessely(a, sqrt(x)), x, s) == \
(-4**s*cos(pi*a/2 - pi*s)*gamma(s - a/2)*gamma(s + a/2)*gamma(S(1)/2 - 2*s)
/ (sqrt(pi)*gamma(S(1)/2 - s - a/2)*gamma(S(1)/2 - s + a/2)),
(Max(-re(a)/2, re(a)/2), S(1)/4), True)
assert MT(besselj(a, sqrt(x))*bessely(a, sqrt(x)), x, s) == \
(-cos(pi*s)*gamma(s)*gamma(a + s)*gamma(S(1)/2 - s)
/ (pi**S('3/2')*gamma(1 + a - s)),
(Max(-re(a), 0), S(1)/2), True)
assert MT(besselj(a, sqrt(x))*bessely(b, sqrt(x)), x, s) == \
(-4**s*cos(pi*a/2 - pi*b/2 + pi*s)*gamma(1 - 2*s)
* gamma(a/2 - b/2 + s)*gamma(a/2 + b/2 + s)
/ (pi*gamma(a/2 - b/2 - s + 1)*gamma(a/2 + b/2 - s + 1)),
(Max((-re(a) + re(b))/2, (-re(a) - re(b))/2), S(1)/2), True)
assert MT(bessely(a, sqrt(x))**2, x, s) == \
((2*cos(pi*a - pi*s)*gamma(s)*gamma(-a + s)*gamma(-s + 1)*gamma(a - s + 1) \
+ pi*gamma(-s + S(1)/2)*gamma(s + S(1)/2)) \
*gamma(a + s)/(pi**(S(3)/2)*gamma(-s + 1)*gamma(s + S(1)/2)*gamma(a - s + 1)),
(Max(-re(a), 0, re(a)), S(1)/2), True)
# TODO bessely(a, sqrt(x))*bessely(b, sqrt(x)) is a mess
# (no matter what way you look at it ...)
# Section 8.4.22
# TODO we can't do any of these (delicate cancellation)
# Section 8.4.23
assert MT(besselk(a, 2*sqrt(x)), x, s) == \
(gamma(s - a/2)*gamma(s + a/2)/2, (Max(-re(a)/2, re(a)/2), oo), True)
# TODO this result needs expansion of F(a, b; c; 1) using gauss-summation
assert MT(exp(-x/2)*besselk(a, x/2), x, s)[1:] == \
((Max(-re(a), re(a)), oo), True)
def test_rewrite():
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)
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, Rational(-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 + Rational(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+ Rational(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 + S.Half) + (x**2 - x/2 - Rational(3, 2))*Dx + (-x**2 + x/2 + 1)*Dx**2 +\
(x**2 + x/2)*Dx**3, x, 0, [2, 1, S.Half])
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.Half, x0=1)
q = HolonomicFunction(x * Dx - S.Half, 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
assert (expr_to_holonomic(sqrt(x) + sqrt(2*x)).to_expr()-\
(sqrt(x) + sqrt(2*x))).simplify() == 0
assert expr_to_holonomic(3 * x +
2 * sqrt(x)).to_expr() == 3 * x + 2 * sqrt(x)
p = expr_to_holonomic((x**4 + x**3 + 5 * x**2 + 3 * x + 2) / x**2,
lenics=3)
q = HolonomicFunction((-2*x**4 - x**3 + 3*x + 4) + (x**5 + x**4 + 5*x**3 + 3*x**2 + \
2*x)*Dx, x, 0, {-2: [2, 3, 5]})
assert p == q
p = expr_to_holonomic(1 / (x - 1)**2, lenics=3, x0=1)
q = HolonomicFunction((2) + (x - 1) * Dx, x, 1, {-2: [1, 0, 0]})
assert p == q
a = symbols("a")
p = expr_to_holonomic(sqrt(a * x), x=x)
assert p.to_expr() == sqrt(a) * sqrt(x)
def test_besselsimp():
from sympy import besselj, besseli, exp_polar, cosh, cosine_transform, bessely
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**Rational(1, 4)*exp(I*pi/4)*exp(-I*pi*a/2) *
besseli(Rational(-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(Rational(-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)
assert cosine_transform(1/t*sin(a/t), t, y) == \
sqrt(2)*sqrt(pi)*besselj(0, 2*sqrt(a)*sqrt(y))/2
assert besselsimp(
x**2 * (a * (-2 * besselj(5 * I, x) + besselj(-2 + 5 * I, x) +
besselj(2 + 5 * I, x)) + b *
(-2 * bessely(5 * I, x) + bessely(-2 + 5 * I, x) +
bessely(2 + 5 * I, x))) / 4 + x *
(a * (besselj(-1 + 5 * I, x) / 2 - besselj(1 + 5 * I, x) / 2) + b *
(bessely(-1 + 5 * I, x) / 2 - bessely(1 + 5 * I, x) / 2)) +
(x**2 + 25) * (a * besselj(5 * I, x) + b * bessely(5 * I, x))) == 0
assert besselsimp(81 * x**2 * (
a *
(besselj(Rational(-5, 3), 9 * x) - 2 * besselj(Rational(1, 3), 9 * x) +
besselj(Rational(7, 3), 9 * x)) + b *
(bessely(Rational(-5, 3), 9 * x) - 2 * bessely(Rational(1, 3), 9 * x) +
bessely(Rational(7, 3), 9 * x))) / 4 + x *
(a * (9 * besselj(Rational(-2, 3), 9 * x) / 2 -
9 * besselj(Rational(4, 3), 9 * x) / 2) + b *
(9 * bessely(Rational(-2, 3), 9 * x) / 2 -
9 * bessely(Rational(4, 3), 9 * x) / 2)) +
(81 * x**2 - Rational(1, 9)) *
(a * besselj(Rational(1, 3), 9 * x) +
b * bessely(Rational(1, 3), 9 * x))) == 0
assert besselsimp(
besselj(a - 1, x) + besselj(a + 1, x) - 2 * a * besselj(a, x) / x) == 0
assert besselsimp(besselj(a - 1, x) + besselj(a + 1, x) +
besselj(a, x)) == (2 * a + x) * besselj(a, x) / x
assert besselsimp(x**2* besselj(a,x) + x**3*besselj(a+1, x) + besselj(a+2, x)) == \
2*a*x*besselj(a + 1, x) + x**3*besselj(a + 1, x) - x**2*besselj(a + 2, x) + 2*x*besselj(a + 1, x) + besselj(a + 2, x)
def test_mellin_transform_bessel():
from sympy import Max
MT = mellin_transform
# 8.4.19
assert MT(besselj(a, 2*sqrt(x)), x, s) == \
(gamma(a/2 + s)/gamma(a/2 - s + 1), (-re(a)/2, S(3)/4), True)
assert MT(sin(sqrt(x))*besselj(a, sqrt(x)), x, s) == \
(2**a*gamma(-2*s + S(1)/2)*gamma(a/2 + s + S(1)/2)/(
gamma(-a/2 - s + 1)*gamma(a - 2*s + 1)), (
-re(a)/2 - S(1)/2, S(1)/4), True)
assert MT(cos(sqrt(x))*besselj(a, sqrt(x)), x, s) == \
(2**a*gamma(a/2 + s)*gamma(-2*s + S(1)/2)/(
gamma(-a/2 - s + S(1)/2)*gamma(a - 2*s + 1)), (
-re(a)/2, S(1)/4), True)
assert MT(besselj(a, sqrt(x))**2, x, s) == \
(gamma(a + s)*gamma(S(1)/2 - s)
/ (sqrt(pi)*gamma(1 - s)*gamma(1 + a - s)),
(-re(a), S(1)/2), True)
assert MT(besselj(a, sqrt(x))*besselj(-a, sqrt(x)), x, s) == \
(gamma(s)*gamma(S(1)/2 - s)
/ (sqrt(pi)*gamma(1 - a - s)*gamma(1 + a - s)),
(0, S(1)/2), True)
# NOTE: prudnikov gives the strip below as (1/2 - re(a), 1). As far as
# I can see this is wrong (since besselj(z) ~ 1/sqrt(z) for z large)
assert MT(besselj(a - 1, sqrt(x))*besselj(a, sqrt(x)), x, s) == \
(gamma(1 - s)*gamma(a + s - S(1)/2)
/ (sqrt(pi)*gamma(S(3)/2 - s)*gamma(a - s + S(1)/2)),
(S(1)/2 - re(a), S(1)/2), True)
assert MT(besselj(a, sqrt(x))*besselj(b, sqrt(x)), x, s) == \
(4**s*gamma(1 - 2*s)*gamma((a + b)/2 + s)
/ (gamma(1 - s + (b - a)/2)*gamma(1 - s + (a - b)/2)
*gamma( 1 - s + (a + b)/2)),
(-(re(a) + re(b))/2, S(1)/2), True)
assert MT(besselj(a, sqrt(x))**2 + besselj(-a, sqrt(x))**2, x, s)[1:] == \
((Max(re(a), -re(a)), S(1)/2), True)
# Section 8.4.20
assert MT(bessely(a, 2*sqrt(x)), x, s) == \
(-cos(pi*(a/2 - s))*gamma(s - a/2)*gamma(s + a/2)/pi,
(Max(-re(a)/2, re(a)/2), S(3)/4), True)
assert MT(sin(sqrt(x))*bessely(a, sqrt(x)), x, s) == \
(-4**s*sin(pi*(a/2 - s))*gamma(S(1)/2 - 2*s)
* gamma((1 - a)/2 + s)*gamma((1 + a)/2 + s)
/ (sqrt(pi)*gamma(1 - s - a/2)*gamma(1 - s + a/2)),
(Max(-(re(a) + 1)/2, (re(a) - 1)/2), S(1)/4), True)
assert MT(cos(sqrt(x))*bessely(a, sqrt(x)), x, s) == \
(-4**s*cos(pi*(a/2 - s))*gamma(s - a/2)*gamma(s + a/2)*gamma(S(1)/2 - 2*s)
/ (sqrt(pi)*gamma(S(1)/2 - s - a/2)*gamma(S(1)/2 - s + a/2)),
(Max(-re(a)/2, re(a)/2), S(1)/4), True)
assert MT(besselj(a, sqrt(x))*bessely(a, sqrt(x)), x, s) == \
(-cos(pi*s)*gamma(s)*gamma(a + s)*gamma(S(1)/2 - s)
/ (pi**S('3/2')*gamma(1 + a - s)),
(Max(-re(a), 0), S(1)/2), True)
assert MT(besselj(a, sqrt(x))*bessely(b, sqrt(x)), x, s) == \
(-4**s*cos(pi*(a/2 - b/2 + s))*gamma(1 - 2*s)
* gamma(a/2 - b/2 + s)*gamma(a/2 + b/2 + s)
/ (pi*gamma(a/2 - b/2 - s + 1)*gamma(a/2 + b/2 - s + 1)),
(Max((-re(a) + re(b))/2, (-re(a) - re(b))/2), S(1)/2), True)
# NOTE bessely(a, sqrt(x))**2 and bessely(a, sqrt(x))*bessely(b, sqrt(x))
# are a mess (no matter what way you look at it ...)
assert MT(bessely(a, sqrt(x))**2, x, s)[1:] == \
((Max(-re(a), 0, re(a)), S(1)/2), True)
# Section 8.4.22
# TODO we can't do any of these (delicate cancellation)
# Section 8.4.23
assert MT(besselk(a, 2*sqrt(x)), x, s) == \
(gamma(
s - a/2)*gamma(s + a/2)/2, (Max(-re(a)/2, re(a)/2), oo), True)
assert MT(
besselj(a, 2 * sqrt(2 * sqrt(x))) * besselk(a, 2 * sqrt(2 * sqrt(x))),
x, s) == (4**(-s) * gamma(2 * s) * gamma(a / 2 + s) /
(2 * gamma(a / 2 - s + 1)), (Max(0, -re(a) / 2), oo), True)
# TODO bessely(a, x)*besselk(a, x) is a mess
assert MT(besseli(a, sqrt(x))*besselk(a, sqrt(x)), x, s) == \
(gamma(s)*gamma(
a + s)*gamma(-s + S(1)/2)/(2*sqrt(pi)*gamma(a - s + 1)),
(Max(-re(a), 0), S(1)/2), True)
assert MT(besseli(b, sqrt(x))*besselk(a, sqrt(x)), x, s) == \
(2**(2*s - 1)*gamma(-2*s + 1)*gamma(-a/2 + b/2 + s)* \
gamma(a/2 + b/2 + s)/(gamma(-a/2 + b/2 - s + 1)* \
gamma(a/2 + b/2 - s + 1)), (Max(-re(a)/2 - re(b)/2, \
re(a)/2 - re(b)/2), S(1)/2), True)
# TODO products of besselk are a mess
mt = MT(exp(-x / 2) * besselk(a, x / 2), x, s)
mt0 = gammasimp((trigsimp(gammasimp(mt[0].expand(func=True)))))
assert mt0 == 2 * pi**(S(3) / 2) * cos(pi * s) * gamma(-s + S(1) / 2) / (
(cos(2 * pi * a) - cos(2 * pi * s)) * gamma(-a - s + 1) *
gamma(a - s + 1))
assert mt[1:] == ((Max(-re(a), re(a)), oo), True)
def test_linear_subs():
from sympy import besselj
assert integrate(sin(x - 1), x, meijerg=True) == -cos(1 - x)
assert integrate(besselj(1, x - 1), x, meijerg=True) == -besselj(0, 1 - x)
def test_expand():
assert expand_func(besselj(S.Half, z).rewrite(jn)) == \
sqrt(2)*sin(z)/(sqrt(pi)*sqrt(z))
assert expand_func(bessely(S.Half, z).rewrite(yn)) == \
-sqrt(2)*cos(z)/(sqrt(pi)*sqrt(z))
# XXX: teach sin/cos to work around arguments like
# x*exp_polar(I*pi*n/2). Then change besselsimp -> expand_func
assert besselsimp(besselj(S.Half,
z)) == sqrt(2) * sin(z) / (sqrt(pi) * sqrt(z))
assert besselsimp(besselj(Rational(-1, 2),
z)) == sqrt(2) * cos(z) / (sqrt(pi) * sqrt(z))
assert besselsimp(besselj(Rational(5, 2), z)) == \
-sqrt(2)*(z**2*sin(z) + 3*z*cos(z) - 3*sin(z))/(sqrt(pi)*z**Rational(5, 2))
assert besselsimp(besselj(Rational(-5, 2), z)) == \
-sqrt(2)*(z**2*cos(z) - 3*z*sin(z) - 3*cos(z))/(sqrt(pi)*z**Rational(5, 2))
assert besselsimp(bessely(S.Half, z)) == \
-(sqrt(2)*cos(z))/(sqrt(pi)*sqrt(z))
assert besselsimp(bessely(Rational(-1, 2),
z)) == sqrt(2) * sin(z) / (sqrt(pi) * sqrt(z))
assert besselsimp(bessely(Rational(5, 2), z)) == \
sqrt(2)*(z**2*cos(z) - 3*z*sin(z) - 3*cos(z))/(sqrt(pi)*z**Rational(5, 2))
assert besselsimp(bessely(Rational(-5, 2), z)) == \
-sqrt(2)*(z**2*sin(z) + 3*z*cos(z) - 3*sin(z))/(sqrt(pi)*z**Rational(5, 2))
assert besselsimp(besseli(S.Half,
z)) == sqrt(2) * sinh(z) / (sqrt(pi) * sqrt(z))
assert besselsimp(besseli(Rational(-1, 2), z)) == \
sqrt(2)*cosh(z)/(sqrt(pi)*sqrt(z))
assert besselsimp(besseli(Rational(5, 2), z)) == \
sqrt(2)*(z**2*sinh(z) - 3*z*cosh(z) + 3*sinh(z))/(sqrt(pi)*z**Rational(5, 2))
assert besselsimp(besseli(Rational(-5, 2), z)) == \
sqrt(2)*(z**2*cosh(z) - 3*z*sinh(z) + 3*cosh(z))/(sqrt(pi)*z**Rational(5, 2))
assert besselsimp(besselk(S.Half, z)) == \
besselsimp(besselk(Rational(-1, 2), z)) == sqrt(pi)*exp(-z)/(sqrt(2)*sqrt(z))
assert besselsimp(besselk(Rational(5, 2), z)) == \
besselsimp(besselk(Rational(-5, 2), z)) == \
sqrt(2)*sqrt(pi)*(z**2 + 3*z + 3)*exp(-z)/(2*z**Rational(5, 2))
n = Symbol('n', integer=True, positive=True)
assert expand_func(besseli(n + 2, z)) == \
besseli(n, z) + (-2*n - 2)*(-2*n*besseli(n, z)/z + besseli(n - 1, z))/z
assert expand_func(besselj(n + 2, z)) == \
-besselj(n, z) + (2*n + 2)*(2*n*besselj(n, z)/z - besselj(n - 1, z))/z
assert expand_func(besselk(n + 2, z)) == \
besselk(n, z) + (2*n + 2)*(2*n*besselk(n, z)/z + besselk(n - 1, z))/z
assert expand_func(bessely(n + 2, z)) == \
-bessely(n, z) + (2*n + 2)*(2*n*bessely(n, z)/z - bessely(n - 1, z))/z
assert expand_func(besseli(n + S.Half, z).rewrite(jn)) == \
(sqrt(2)*sqrt(z)*exp(-I*pi*(n + S.Half)/2) *
exp_polar(I*pi/4)*jn(n, z*exp_polar(I*pi/2))/sqrt(pi))
assert expand_func(besselj(n + S.Half, z).rewrite(jn)) == \
sqrt(2)*sqrt(z)*jn(n, z)/sqrt(pi)
r = Symbol('r', real=True)
p = Symbol('p', positive=True)
i = Symbol('i', integer=True)
for besselx in [besselj, bessely, besseli, besselk]:
assert besselx(i, p).is_extended_real is True
assert besselx(i, x).is_extended_real is None
assert besselx(x, z).is_extended_real is None
for besselx in [besselj, besseli]:
assert besselx(i, r).is_extended_real is True
for besselx in [bessely, besselk]:
assert besselx(i, r).is_extended_real is None
for besselx in [besselj, bessely, besseli, besselk]:
assert expand_func(besselx(oo, x)) == besselx(oo, x, evaluate=False)
assert expand_func(besselx(-oo, x)) == besselx(-oo, x, evaluate=False)