def test_expint(): """ Test various exponential integrals. """ from sympy import (expint, unpolarify, Symbol, Ci, Si, Shi, Chi, sin, cos, sinh, cosh, Ei) assert simplify( unpolarify( integrate(exp(-z * x) / x**y, (x, 1, oo), meijerg=True, conds='none').rewrite(expint).expand( func=True))) == expint(y, z) assert integrate(exp(-z*x)/x, (x, 1, oo), meijerg=True, conds='none').rewrite(expint).expand() == \ expint(1, z) assert integrate(exp(-z*x)/x**2, (x, 1, oo), meijerg=True, conds='none').rewrite(expint).expand() == \ expint(2, z).rewrite(Ei).rewrite(expint) assert integrate(exp(-z*x)/x**3, (x, 1, oo), meijerg=True, conds='none').rewrite(expint).expand() == \ expint(3, z).rewrite(Ei).rewrite(expint).expand() t = Symbol('t', positive=True) assert integrate(-cos(x) / x, (x, t, oo), meijerg=True).expand() == Ci(t) assert integrate(-sin(x)/x, (x, t, oo), meijerg=True).expand() == \ Si(t) - pi/2 assert integrate(sin(x) / x, (x, 0, z), meijerg=True) == Si(z) assert integrate(sinh(x) / x, (x, 0, z), meijerg=True) == Shi(z) assert integrate(exp(-x)/x, x, meijerg=True).expand().rewrite(expint) == \ I*pi - expint(1, x) assert integrate(exp(-x)/x**2, x, meijerg=True).rewrite(expint).expand() \ == expint(1, x) - exp(-x)/x - I*pi u = Symbol('u', polar=True) assert integrate(cos(u)/u, u, meijerg=True).expand().as_independent(u)[1] \ == Ci(u) assert integrate(cosh(u)/u, u, meijerg=True).expand().as_independent(u)[1] \ == Chi(u) assert integrate( expint(1, x), x, meijerg=True).rewrite(expint).expand() == x * expint(1, x) - exp(-x) assert integrate(expint(2, x), x, meijerg=True ).rewrite(expint).expand() == \ -x**2*expint(1, x)/2 + x*exp(-x)/2 - exp(-x)/2 assert simplify(unpolarify(integrate(expint(y, x), x, meijerg=True).rewrite(expint).expand(func=True))) == \ -expint(y + 1, x) assert integrate(Si(x), x, meijerg=True) == x * Si(x) + cos(x) assert integrate(Ci(u), u, meijerg=True).expand() == u * Ci(u) - sin(u) assert integrate(Shi(x), x, meijerg=True) == x * Shi(x) - cosh(x) assert integrate(Chi(u), u, meijerg=True).expand() == u * Chi(u) - sinh(u) assert integrate(Si(x) * exp(-x), (x, 0, oo), meijerg=True) == pi / 4 assert integrate(expint(1, x) * sin(x), (x, 0, oo), meijerg=True) == log(2) / 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_manualintegrate_special(): f, F = 4*exp(-x**2/3), 2*sqrt(3)*sqrt(pi)*erf(sqrt(3)*x/3) assert manualintegrate(f, x) == F and F.diff(x).equals(f) f, F = 3*exp(4*x**2), 3*sqrt(pi)*erfi(2*x)/4 assert manualintegrate(f, x) == F and F.diff(x).equals(f) f, F = x**Rational(1, 3)*exp(-x/8), -16*uppergamma(Rational(4, 3), x/8) assert manualintegrate(f, x) == F and F.diff(x).equals(f) f, F = exp(2*x)/x, Ei(2*x) assert manualintegrate(f, x) == F and F.diff(x).equals(f) f, F = exp(1 + 2*x - x**2), sqrt(pi)*exp(2)*erf(x - 1)/2 assert manualintegrate(f, x) == F and F.diff(x).equals(f) f = sin(x**2 + 4*x + 1) F = (sqrt(2)*sqrt(pi)*(-sin(3)*fresnelc(sqrt(2)*(2*x + 4)/(2*sqrt(pi))) + cos(3)*fresnels(sqrt(2)*(2*x + 4)/(2*sqrt(pi))))/2) assert manualintegrate(f, x) == F and F.diff(x).equals(f) f, F = cos(4*x**2), sqrt(2)*sqrt(pi)*fresnelc(2*sqrt(2)*x/sqrt(pi))/4 assert manualintegrate(f, x) == F and F.diff(x).equals(f) f, F = sin(3*x + 2)/x, sin(2)*Ci(3*x) + cos(2)*Si(3*x) assert manualintegrate(f, x) == F and F.diff(x).equals(f) f, F = sinh(3*x - 2)/x, -sinh(2)*Chi(3*x) + cosh(2)*Shi(3*x) assert manualintegrate(f, x) == F and F.diff(x).equals(f) f, F = 5*cos(2*x - 3)/x, 5*cos(3)*Ci(2*x) + 5*sin(3)*Si(2*x) assert manualintegrate(f, x) == F and F.diff(x).equals(f) f, F = cosh(x/2)/x, Chi(x/2) assert manualintegrate(f, x) == F and F.diff(x).equals(f) f, F = cos(x**2)/x, Ci(x**2)/2 assert manualintegrate(f, x) == F and F.diff(x).equals(f) f, F = 1/log(2*x + 1), li(2*x + 1)/2 assert manualintegrate(f, x) == F and F.diff(x).equals(f) f, F = polylog(2, 5*x)/x, polylog(3, 5*x) assert manualintegrate(f, x) == F and F.diff(x).equals(f) f, F = 5/sqrt(3 - 2*sin(x)**2), 5*sqrt(3)*elliptic_f(x, Rational(2, 3))/3 assert manualintegrate(f, x) == F and F.diff(x).equals(f) f, F = sqrt(4 + 9*sin(x)**2), 2*elliptic_e(x, Rational(-9, 4)) assert manualintegrate(f, x) == F and F.diff(x).equals(f)
def test_ei(): assert tn_branch(Ei) assert mytd(Ei(x), exp(x) / x, x) assert mytn(Ei(x), Ei(x).rewrite(uppergamma), -uppergamma(0, x * polar_lift(-1)) - I * pi, x) assert mytn(Ei(x), Ei(x).rewrite(expint), -expint(1, x * polar_lift(-1)) - I * pi, x) assert Ei(x).rewrite(expint).rewrite(Ei) == Ei(x) assert Ei(x * exp_polar(2 * I * pi)) == Ei(x) + 2 * I * pi assert Ei(x * exp_polar(-2 * I * pi)) == Ei(x) - 2 * I * pi assert mytn(Ei(x), Ei(x).rewrite(Shi), Chi(x) + Shi(x), x) assert mytn(Ei(x * polar_lift(I)), Ei(x * polar_lift(I)).rewrite(Si), Ci(x) + I * Si(x) + I * pi / 2, x) assert Ei(log(x)).rewrite(li) == li(x) assert Ei(2 * log(x)).rewrite(li) == li(x**2) assert gruntz(Ei(x + exp(-x)) * exp(-x) * x, x, oo) == 1 assert Ei(x).series(x) == EulerGamma + log(x) + x + x**2/4 + \ x**3/18 + x**4/96 + x**5/600 + O(x**6) assert str(Ei(cos(2)).evalf(n=10)) == '-0.6760647401'
def test_ei(): assert Ei(0) == S.NegativeInfinity assert Ei(oo) == S.Infinity assert Ei(-oo) == S.Zero assert tn_branch(Ei) assert mytd(Ei(x), exp(x) / x, x) assert mytn(Ei(x), Ei(x).rewrite(uppergamma), -uppergamma(0, x * polar_lift(-1)) - I * pi, x) assert mytn(Ei(x), Ei(x).rewrite(expint), -expint(1, x * polar_lift(-1)) - I * pi, x) assert Ei(x).rewrite(expint).rewrite(Ei) == Ei(x) assert Ei(x * exp_polar(2 * I * pi)) == Ei(x) + 2 * I * pi assert Ei(x * exp_polar(-2 * I * pi)) == Ei(x) - 2 * I * pi assert mytn(Ei(x), Ei(x).rewrite(Shi), Chi(x) + Shi(x), x) assert mytn(Ei(x * polar_lift(I)), Ei(x * polar_lift(I)).rewrite(Si), Ci(x) + I * Si(x) + I * pi / 2, x) assert Ei(log(x)).rewrite(li) == li(x) assert Ei(2 * log(x)).rewrite(li) == li(x**2) assert gruntz(Ei(x + exp(-x)) * exp(-x) * x, x, oo) == 1 assert Ei(x).series(x) == EulerGamma + log(x) + x + x**2/4 + \ x**3/18 + x**4/96 + x**5/600 + O(x**6) assert Ei(x).series(x, 1, 3) == Ei(1) + E * (x - 1) + O((x - 1)**3, (x, 1)) assert str(Ei(cos(2)).evalf(n=10)) == '-0.6760647401' raises(ArgumentIndexError, lambda: Ei(x).fdiff(2))
def test_ei(): pos = Symbol('p', positive=True) neg = Symbol('n', negative=True) assert Ei(-pos) == Ei(polar_lift(-1)*pos) - I*pi assert Ei(neg) == Ei(polar_lift(neg)) - I*pi assert tn_branch(Ei) assert mytd(Ei(x), exp(x)/x, x) assert mytn(Ei(x), Ei(x).rewrite(uppergamma), -uppergamma(0, x*polar_lift(-1)) - I*pi, x) assert mytn(Ei(x), Ei(x).rewrite(expint), -expint(1, x*polar_lift(-1)) - I*pi, x) assert Ei(x).rewrite(expint).rewrite(Ei) == Ei(x) assert Ei(x*exp_polar(2*I*pi)) == Ei(x) + 2*I*pi assert Ei(x*exp_polar(-2*I*pi)) == Ei(x) - 2*I*pi assert mytn(Ei(x), Ei(x).rewrite(Shi), Chi(x) + Shi(x), x) assert mytn(Ei(x*polar_lift(I)), Ei(x*polar_lift(I)).rewrite(Si), Ci(x) + I*Si(x) + I*pi/2, x) assert Ei(log(x)).rewrite(li) == li(x) assert Ei(2*log(x)).rewrite(li) == li(x**2) assert gruntz(Ei(x+exp(-x))*exp(-x)*x, x, oo) == 1 assert Ei(x).series(x) == EulerGamma + log(x) + x + x**2/4 + \ x**3/18 + x**4/96 + x**5/600 + O(x**6)
def test_li(): z = Symbol("z") zr = Symbol("z", real=True) zp = Symbol("z", positive=True) zn = Symbol("z", negative=True) assert li(0) == 0 assert li(1) is -oo assert li(oo) is oo assert isinstance(li(z), li) assert unchanged(li, -zp) assert unchanged(li, zn) assert diff(li(z), z) == 1 / log(z) assert conjugate(li(z)) == li(conjugate(z)) assert conjugate(li(-zr)) == li(-zr) assert unchanged(conjugate, li(-zp)) assert unchanged(conjugate, li(zn)) assert li(z).rewrite(Li) == Li(z) + li(2) assert li(z).rewrite(Ei) == Ei(log(z)) assert li(z).rewrite(uppergamma) == (-log(1 / log(z)) / 2 - log(-log(z)) + log(log(z)) / 2 - expint(1, -log(z))) assert li(z).rewrite(Si) == (-log(I * log(z)) - log(1 / log(z)) / 2 + log(log(z)) / 2 + Ci(I * log(z)) + Shi(log(z))) assert li(z).rewrite(Ci) == (-log(I * log(z)) - log(1 / log(z)) / 2 + log(log(z)) / 2 + Ci(I * log(z)) + Shi(log(z))) assert li(z).rewrite(Shi) == (-log(1 / log(z)) / 2 + log(log(z)) / 2 + Chi(log(z)) - Shi(log(z))) assert li(z).rewrite(Chi) == (-log(1 / log(z)) / 2 + log(log(z)) / 2 + Chi(log(z)) - Shi(log(z))) assert li(z).rewrite(hyper) == (log(z) * hyper( (1, 1), (2, 2), log(z)) - log(1 / log(z)) / 2 + log(log(z)) / 2 + EulerGamma) assert li(z).rewrite(meijerg) == (-log(1 / log(z)) / 2 - log(-log(z)) + log(log(z)) / 2 - meijerg( ((), (1, )), ((0, 0), ()), -log(z))) assert gruntz(1 / li(z), z, oo) == 0 assert li(z).series(z) == log(z)**5/600 + log(z)**4/96 + log(z)**3/18 + log(z)**2/4 + \ log(z) + log(log(z)) + EulerGamma raises(ArgumentIndexError, lambda: li(z).fdiff(2))
def test_expint(): assert mytn(expint(x, y), expint(x, y).rewrite(uppergamma), y**(x - 1) * uppergamma(1 - x, y), x) assert mytd(expint(x, y), -y**(x - 1) * meijerg([], [1, 1], [0, 0, 1 - x], [], y), x) assert mytd(expint(x, y), -expint(x - 1, y), y) assert mytn(expint(1, x), expint(1, x).rewrite(Ei), -Ei(x * polar_lift(-1)) + I * pi, x) assert expint(-4, x) == exp(-x)/x + 4*exp(-x)/x**2 + 12*exp(-x)/x**3 \ + 24*exp(-x)/x**4 + 24*exp(-x)/x**5 assert expint(-S(3)/2, x) == \ exp(-x)/x + 3*exp(-x)/(2*x**2) + 3*sqrt(pi)*erfc(sqrt(x))/(4*x**S('5/2')) assert tn_branch(expint, 1) assert tn_branch(expint, 2) assert tn_branch(expint, 3) assert tn_branch(expint, 1.7) assert tn_branch(expint, pi) assert expint(y, x*exp_polar(2*I*pi)) == \ x**(y - 1)*(exp(2*I*pi*y) - 1)*gamma(-y + 1) + expint(y, x) assert expint(y, x*exp_polar(-2*I*pi)) == \ x**(y - 1)*(exp(-2*I*pi*y) - 1)*gamma(-y + 1) + expint(y, x) assert expint(2, x * exp_polar(2 * I * pi)) == 2 * I * pi * x + expint(2, x) assert expint(2, x * exp_polar(-2 * I * pi)) == -2 * I * pi * x + expint(2, x) assert expint(1, x).rewrite(Ei).rewrite(expint) == expint(1, x) assert expint(x, y).rewrite(Ei) == expint(x, y) assert expint(x, y).rewrite(Ci) == expint(x, y) assert mytn(E1(x), E1(x).rewrite(Shi), Shi(x) - Chi(x), x) assert mytn(E1(polar_lift(I) * x), E1(polar_lift(I) * x).rewrite(Si), -Ci(x) + I * Si(x) - I * pi / 2, x) assert mytn(expint(2, x), expint(2, x).rewrite(Ei).rewrite(expint), -x * E1(x) + exp(-x), x) assert mytn(expint(3, x), expint(3, x).rewrite(Ei).rewrite(expint), x**2 * E1(x) / 2 + (1 - x) * exp(-x) / 2, x) assert expint(S(3)/2, z).nseries(z) == \ 2 + 2*z - z**2/3 + z**3/15 - z**4/84 + z**5/540 - \ 2*sqrt(pi)*sqrt(z) + O(z**6) assert E1(z).series(z) == -EulerGamma - log(z) + z - \ z**2/4 + z**3/18 - z**4/96 + z**5/600 + O(z**6) assert expint(4, z).series(z) == S(1)/3 - z/2 + z**2/2 + \ z**3*(log(z)/6 - S(11)/36 + EulerGamma/6) - z**4/24 + \ z**5/240 + O(z**6) assert expint(z, y).series(z, 0, 2) == exp(-y) / y - z * meijerg( ((), (1, 1)), ((0, 0, 1), ()), y) / y + O(z**2) raises(ArgumentIndexError, lambda: expint(x, y).fdiff(3))
def test_li(): z = Symbol("z") zr = Symbol("z", real=True) zp = Symbol("z", positive=True) zn = Symbol("z", negative=True) assert li(0) == 0 assert li(1) == -oo assert li(oo) == oo assert isinstance(li(z), li) assert diff(li(z), z) == 1 / log(z) assert conjugate(li(z)) == li(conjugate(z)) assert conjugate(li(-zr)) == li(-zr) assert conjugate(li(-zp)) == conjugate(li(-zp)) assert conjugate(li(zn)) == conjugate(li(zn)) assert li(z).rewrite(Li) == Li(z) + li(2) assert li(z).rewrite(Ei) == Ei(log(z)) assert li(z).rewrite(uppergamma) == (-log(1 / log(z)) / 2 - log(-log(z)) + log(log(z)) / 2 - expint(1, -log(z))) assert li(z).rewrite(Si) == (-log(I * log(z)) - log(1 / log(z)) / 2 + log(log(z)) / 2 + Ci(I * log(z)) + Shi(log(z))) assert li(z).rewrite(Ci) == (-log(I * log(z)) - log(1 / log(z)) / 2 + log(log(z)) / 2 + Ci(I * log(z)) + Shi(log(z))) assert li(z).rewrite(Shi) == (-log(1 / log(z)) / 2 + log(log(z)) / 2 + Chi(log(z)) - Shi(log(z))) assert li(z).rewrite(Chi) == (-log(1 / log(z)) / 2 + log(log(z)) / 2 + Chi(log(z)) - Shi(log(z))) assert li(z).rewrite(hyper) == (log(z) * hyper( (1, 1), (2, 2), log(z)) - log(1 / log(z)) / 2 + log(log(z)) / 2 + EulerGamma) assert li(z).rewrite(meijerg) == (-log(1 / log(z)) / 2 - log(-log(z)) + log(log(z)) / 2 - meijerg( ((), (1, )), ((0, 0), ()), -log(z))) assert gruntz(1 / li(z), z, oo) == 0
def test_expint(): assert mytn(expint(x, y), expint(x, y).rewrite(uppergamma), y**(x - 1) * uppergamma(1 - x, y), x) assert mytd(expint(x, y), -y**(x - 1) * meijerg([], [1, 1], [0, 0, 1 - x], [], y), x) assert mytd(expint(x, y), -expint(x - 1, y), y) assert mytn(expint(1, x), expint(1, x).rewrite(Ei), -Ei(x * polar_lift(-1)) + I * pi, x) assert expint(-4, x) == exp(-x)/x + 4*exp(-x)/x**2 + 12*exp(-x)/x**3 \ + 24*exp(-x)/x**4 + 24*exp(-x)/x**5 assert expint(-S(3)/2, x) == \ exp(-x)/x + 3*exp(-x)/(2*x**2) - 3*sqrt(pi)*erf(sqrt(x))/(4*x**S('5/2')) \ + 3*sqrt(pi)/(4*x**S('5/2')) assert tn_branch(expint, 1) assert tn_branch(expint, 2) assert tn_branch(expint, 3) assert tn_branch(expint, 1.7) assert tn_branch(expint, pi) assert expint(y, x*exp_polar(2*I*pi)) == \ x**(y - 1)*(exp(2*I*pi*y) - 1)*gamma(-y + 1) + expint(y, x) assert expint(y, x*exp_polar(-2*I*pi)) == \ x**(y - 1)*(exp(-2*I*pi*y) - 1)*gamma(-y + 1) + expint(y, x) assert expint(2, x * exp_polar(2 * I * pi)) == 2 * I * pi * x + expint(2, x) assert expint(2, x * exp_polar(-2 * I * pi)) == -2 * I * pi * x + expint(2, x) assert expint(1, x).rewrite(Ei).rewrite(expint) == expint(1, x) assert mytn(E1(x), E1(x).rewrite(Shi), Shi(x) - Chi(x), x) assert mytn(E1(polar_lift(I) * x), E1(polar_lift(I) * x).rewrite(Si), -Ci(x) + I * Si(x) - I * pi / 2, x) assert mytn(expint(2, x), expint(2, x).rewrite(Ei).rewrite(expint), -x * E1(x) + exp(-x), x) assert mytn(expint(3, x), expint(3, x).rewrite(Ei).rewrite(expint), x**2 * E1(x) / 2 + (1 - x) * exp(-x) / 2, x)
def test_ei(): pos = Symbol('p', positive=True) neg = Symbol('n', negative=True) assert Ei(-pos) == Ei(polar_lift(-1) * pos) - I * pi assert Ei(neg) == Ei(polar_lift(neg)) - I * pi assert tn_branch(Ei) assert mytd(Ei(x), exp(x) / x, x) assert mytn(Ei(x), Ei(x).rewrite(uppergamma), -uppergamma(0, x * polar_lift(-1)) - I * pi, x) assert mytn(Ei(x), Ei(x).rewrite(expint), -expint(1, x * polar_lift(-1)) - I * pi, x) assert Ei(x).rewrite(expint).rewrite(Ei) == Ei(x) assert Ei(x * exp_polar(2 * I * pi)) == Ei(x) + 2 * I * pi assert Ei(x * exp_polar(-2 * I * pi)) == Ei(x) - 2 * I * pi assert mytn(Ei(x), Ei(x).rewrite(Shi), Chi(x) + Shi(x), x) assert mytn(Ei(x * polar_lift(I)), Ei(x * polar_lift(I)).rewrite(Si), Ci(x) + I * Si(x) + I * pi / 2, x)
def test_si(): assert Si(I*x) == I*Shi(x) assert Shi(I*x) == I*Si(x) assert Si(-I*x) == -I*Shi(x) assert Shi(-I*x) == -I*Si(x) assert Si(-x) == -Si(x) assert Shi(-x) == -Shi(x) assert Si(exp_polar(2*pi*I)*x) == Si(x) assert Si(exp_polar(-2*pi*I)*x) == Si(x) assert Shi(exp_polar(2*pi*I)*x) == Shi(x) assert Shi(exp_polar(-2*pi*I)*x) == Shi(x) assert Si(oo) == pi/2 assert Si(-oo) == -pi/2 assert Shi(oo) == oo assert Shi(-oo) == -oo assert mytd(Si(x), sin(x)/x, x) assert mytd(Shi(x), sinh(x)/x, x) assert mytn(Si(x), Si(x).rewrite(Ei), -I*(-Ei(x*exp_polar(-I*pi/2))/2 + Ei(x*exp_polar(I*pi/2))/2 - I*pi) + pi/2, x) assert mytn(Si(x), Si(x).rewrite(expint), -I*(-expint(1, x*exp_polar(-I*pi/2))/2 + expint(1, x*exp_polar(I*pi/2))/2) + pi/2, x) assert mytn(Shi(x), Shi(x).rewrite(Ei), Ei(x)/2 - Ei(x*exp_polar(I*pi))/2 + I*pi/2, x) assert mytn(Shi(x), Shi(x).rewrite(expint), expint(1, x)/2 - expint(1, x*exp_polar(I*pi))/2 - I*pi/2, x) assert tn_arg(Si) assert tn_arg(Shi) assert Si(x).nseries(x, n=8) == \ x - x**3/18 + x**5/600 - x**7/35280 + O(x**9) assert Shi(x).nseries(x, n=8) == \ x + x**3/18 + x**5/600 + x**7/35280 + O(x**9) assert Si(sin(x)).nseries(x, n=5) == x - 2*x**3/9 + 17*x**5/450 + O(x**6) assert Si(x).nseries(x, 1, n=3) == \ Si(1) + (x - 1)*sin(1) + (x - 1)**2*(-sin(1)/2 + cos(1)/2) + O((x - 1)**3, (x, 1)) t = Symbol('t', Dummy=True) assert Si(x).rewrite(sinc) == Integral(sinc(t), (t, 0, x))
def test_latex_functions(): assert latex(exp(x)) == "e^{x}" assert latex(exp(1) + exp(2)) == "e + e^{2}" f = Function('f') assert latex(f(x)) == '\\operatorname{f}{\\left (x \\right )}' beta = Function('beta') assert latex(beta(x)) == r"\beta{\left (x \right )}" assert latex(sin(x)) == r"\sin{\left (x \right )}" assert latex(sin(x), fold_func_brackets=True) == r"\sin {x}" assert latex(sin(2*x**2), fold_func_brackets=True) == \ r"\sin {2 x^{2}}" assert latex(sin(x**2), fold_func_brackets=True) == \ r"\sin {x^{2}}" assert latex(asin(x)**2) == r"\operatorname{asin}^{2}{\left (x \right )}" assert latex(asin(x)**2, inv_trig_style="full") == \ r"\arcsin^{2}{\left (x \right )}" assert latex(asin(x)**2, inv_trig_style="power") == \ r"\sin^{-1}{\left (x \right )}^{2}" assert latex(asin(x**2), inv_trig_style="power", fold_func_brackets=True) == \ r"\sin^{-1} {x^{2}}" assert latex(factorial(k)) == r"k!" assert latex(factorial(-k)) == r"\left(- k\right)!" assert latex(subfactorial(k)) == r"!k" assert latex(subfactorial(-k)) == r"!\left(- k\right)" assert latex(factorial2(k)) == r"k!!" assert latex(factorial2(-k)) == r"\left(- k\right)!!" assert latex(binomial(2, k)) == r"{\binom{2}{k}}" assert latex(FallingFactorial(3, k)) == r"{\left(3\right)}_{\left(k\right)}" assert latex(RisingFactorial(3, k)) == r"{\left(3\right)}^{\left(k\right)}" assert latex(floor(x)) == r"\lfloor{x}\rfloor" assert latex(ceiling(x)) == r"\lceil{x}\rceil" assert latex(Min(x, 2, x**3)) == r"\min\left(2, x, x^{3}\right)" assert latex(Min(x, y)**2) == r"\min\left(x, y\right)^{2}" assert latex(Max(x, 2, x**3)) == r"\max\left(2, x, x^{3}\right)" assert latex(Max(x, y)**2) == r"\max\left(x, y\right)^{2}" assert latex(Abs(x)) == r"\lvert{x}\rvert" assert latex(re(x)) == r"\Re{x}" assert latex(re(x + y)) == r"\Re{x} + \Re{y}" assert latex(im(x)) == r"\Im{x}" assert latex(conjugate(x)) == r"\overline{x}" assert latex(gamma(x)) == r"\Gamma\left(x\right)" assert latex(Order(x)) == r"\mathcal{O}\left(x\right)" assert latex(lowergamma(x, y)) == r'\gamma\left(x, y\right)' assert latex(uppergamma(x, y)) == r'\Gamma\left(x, y\right)' assert latex(cot(x)) == r'\cot{\left (x \right )}' assert latex(coth(x)) == r'\coth{\left (x \right )}' assert latex(re(x)) == r'\Re{x}' assert latex(im(x)) == r'\Im{x}' assert latex(root(x, y)) == r'x^{\frac{1}{y}}' assert latex(arg(x)) == r'\arg{\left (x \right )}' assert latex(zeta(x)) == r'\zeta\left(x\right)' assert latex(zeta(x)) == r"\zeta\left(x\right)" assert latex(zeta(x)**2) == r"\zeta^{2}\left(x\right)" assert latex(zeta(x, y)) == r"\zeta\left(x, y\right)" assert latex(zeta(x, y)**2) == r"\zeta^{2}\left(x, y\right)" assert latex(dirichlet_eta(x)) == r"\eta\left(x\right)" assert latex(dirichlet_eta(x)**2) == r"\eta^{2}\left(x\right)" assert latex(polylog(x, y)) == r"\operatorname{Li}_{x}\left(y\right)" assert latex(polylog(x, y)**2) == r"\operatorname{Li}_{x}^{2}\left(y\right)" assert latex(lerchphi(x, y, n)) == r"\Phi\left(x, y, n\right)" assert latex(lerchphi(x, y, n)**2) == r"\Phi^{2}\left(x, y, n\right)" assert latex(Ei(x)) == r'\operatorname{Ei}{\left (x \right )}' assert latex(Ei(x)**2) == r'\operatorname{Ei}^{2}{\left (x \right )}' assert latex(expint(x, y)**2) == r'\operatorname{E}_{x}^{2}\left(y\right)' assert latex(Shi(x)**2) == r'\operatorname{Shi}^{2}{\left (x \right )}' assert latex(Si(x)**2) == r'\operatorname{Si}^{2}{\left (x \right )}' assert latex(Ci(x)**2) == r'\operatorname{Ci}^{2}{\left (x \right )}' assert latex(Chi(x)**2) == r'\operatorname{Chi}^{2}{\left (x \right )}' assert latex(jacobi(n, a, b, x)) == r'P_{n}^{\left(a,b\right)}\left(x\right)' assert latex(jacobi( n, a, b, x)**2) == r'\left(P_{n}^{\left(a,b\right)}\left(x\right)\right)^{2}' assert latex(gegenbauer(n, a, x)) == r'C_{n}^{\left(a\right)}\left(x\right)' assert latex(gegenbauer( n, a, x)**2) == r'\left(C_{n}^{\left(a\right)}\left(x\right)\right)^{2}' assert latex(chebyshevt(n, x)) == r'T_{n}\left(x\right)' assert latex(chebyshevt(n, x)**2) == r'\left(T_{n}\left(x\right)\right)^{2}' assert latex(chebyshevu(n, x)) == r'U_{n}\left(x\right)' assert latex(chebyshevu(n, x)**2) == r'\left(U_{n}\left(x\right)\right)^{2}' assert latex(legendre(n, x)) == r'P_{n}\left(x\right)' assert latex(legendre(n, x)**2) == r'\left(P_{n}\left(x\right)\right)^{2}' assert latex(assoc_legendre(n, a, x)) == r'P_{n}^{\left(a\right)}\left(x\right)' assert latex(assoc_legendre( n, a, x)**2) == r'\left(P_{n}^{\left(a\right)}\left(x\right)\right)^{2}' assert latex(laguerre(n, x)) == r'L_{n}\left(x\right)' assert latex(laguerre(n, x)**2) == r'\left(L_{n}\left(x\right)\right)^{2}' assert latex(assoc_laguerre(n, a, x)) == r'L_{n}^{\left(a\right)}\left(x\right)' assert latex(assoc_laguerre( n, a, x)**2) == r'\left(L_{n}^{\left(a\right)}\left(x\right)\right)^{2}' assert latex(hermite(n, x)) == r'H_{n}\left(x\right)' assert latex(hermite(n, x)**2) == r'\left(H_{n}\left(x\right)\right)^{2}' # Test latex printing of function names with "_" assert latex( polar_lift(0)) == r"\operatorname{polar\_lift}{\left (0 \right )}" assert latex(polar_lift(0)** 3) == r"\operatorname{polar\_lift}^{3}{\left (0 \right )}"
def test_latex_functions(): assert latex(exp(x)) == "e^{x}" assert latex(exp(1) + exp(2)) == "e + e^{2}" f = Function('f') assert latex(f(x)) == '\\operatorname{f}{\\left (x \\right )}' beta = Function('beta') assert latex(beta(x)) == r"\beta{\left (x \right )}" assert latex(sin(x)) == r"\sin{\left (x \right )}" assert latex(sin(x), fold_func_brackets=True) == r"\sin {x}" assert latex(sin(2*x**2), fold_func_brackets=True) == \ r"\sin {2 x^{2}}" assert latex(sin(x**2), fold_func_brackets=True) == \ r"\sin {x^{2}}" assert latex(asin(x)**2) == r"\operatorname{asin}^{2}{\left (x \right )}" assert latex(asin(x)**2, inv_trig_style="full") == \ r"\arcsin^{2}{\left (x \right )}" assert latex(asin(x)**2, inv_trig_style="power") == \ r"\sin^{-1}{\left (x \right )}^{2}" assert latex(asin(x**2), inv_trig_style="power", fold_func_brackets=True) == \ r"\sin^{-1} {x^{2}}" assert latex(factorial(k)) == r"k!" assert latex(factorial(-k)) == r"\left(- k\right)!" assert latex(factorial2(k)) == r"k!!" assert latex(factorial2(-k)) == r"\left(- k\right)!!" assert latex(binomial(2, k)) == r"{\binom{2}{k}}" assert latex(FallingFactorial(3, k)) == r"{\left(3\right)}_{\left(k\right)}" assert latex(RisingFactorial(3, k)) == r"{\left(3\right)}^{\left(k\right)}" assert latex(floor(x)) == r"\lfloor{x}\rfloor" assert latex(ceiling(x)) == r"\lceil{x}\rceil" assert latex(Min(x, 2, x**3)) == r"\min\left(2, x, x^{3}\right)" assert latex(Max(x, 2, x**3)) == r"\max\left(2, x, x^{3}\right)" assert latex(Abs(x)) == r"\lvert{x}\rvert" assert latex(re(x)) == r"\Re{x}" assert latex(re(x + y)) == r"\Re {\left (x + y \right )}" assert latex(im(x)) == r"\Im{x}" assert latex(conjugate(x)) == r"\overline{x}" assert latex(gamma(x)) == r"\Gamma\left(x\right)" assert latex(Order(x)) == r"\mathcal{O}\left(x\right)" assert latex(lowergamma(x, y)) == r'\gamma\left(x, y\right)' assert latex(uppergamma(x, y)) == r'\Gamma\left(x, y\right)' assert latex(cot(x)) == r'\cot{\left (x \right )}' assert latex(coth(x)) == r'\coth{\left (x \right )}' assert latex(re(x)) == r'\Re{x}' assert latex(im(x)) == r'\Im{x}' assert latex(root(x, y)) == r'x^{\frac{1}{y}}' assert latex(arg(x)) == r'\arg{\left (x \right )}' assert latex(zeta(x)) == r'\zeta\left(x\right)' assert latex(zeta(x)) == r"\zeta\left(x\right)" assert latex(zeta(x)**2) == r"\zeta^{2}\left(x\right)" assert latex(zeta(x, y)) == r"\zeta\left(x, y\right)" assert latex(zeta(x, y)**2) == r"\zeta^{2}\left(x, y\right)" assert latex(dirichlet_eta(x)) == r"\eta\left(x\right)" assert latex(dirichlet_eta(x)**2) == r"\eta^{2}\left(x\right)" assert latex(polylog(x, y)) == r"\operatorname{Li}_{x}\left(y\right)" assert latex(polylog(x, y)**2) == r"\operatorname{Li}_{x}^{2}\left(y\right)" assert latex(lerchphi(x, y, n)) == r"\Phi\left(x, y, n\right)" assert latex(lerchphi(x, y, n)**2) == r"\Phi^{2}\left(x, y, n\right)" assert latex(Ei(x)) == r'\operatorname{Ei}{\left (x \right )}' assert latex(Ei(x)**2) == r'\operatorname{Ei}^{2}{\left (x \right )}' assert latex(expint(x, y)**2) == r'\operatorname{E}_{x}^{2}\left(y\right)' assert latex(Shi(x)**2) == r'\operatorname{Shi}^{2}{\left (x \right )}' assert latex(Si(x)**2) == r'\operatorname{Si}^{2}{\left (x \right )}' assert latex(Ci(x)**2) == r'\operatorname{Ci}^{2}{\left (x \right )}' assert latex(Chi(x)**2) == r'\operatorname{Chi}^{2}{\left (x \right )}'
def test_latex_functions(): assert latex(exp(x)) == "e^{x}" assert latex(exp(1) + exp(2)) == "e + e^{2}" f = Function('f') assert latex(f(x)) == r'f{\left (x \right )}' assert latex(f) == r'f' g = Function('g') assert latex(g(x, y)) == r'g{\left (x,y \right )}' assert latex(g) == r'g' h = Function('h') assert latex(h(x, y, z)) == r'h{\left (x,y,z \right )}' assert latex(h) == r'h' Li = Function('Li') assert latex(Li) == r'\operatorname{Li}' assert latex(Li(x)) == r'\operatorname{Li}{\left (x \right )}' beta = Function('beta') # not to be confused with the beta function assert latex(beta(x)) == r"\beta{\left (x \right )}" assert latex(beta) == r"\beta" assert latex(sin(x)) == r"\sin{\left (x \right )}" assert latex(sin(x), fold_func_brackets=True) == r"\sin {x}" assert latex(sin(2*x**2), fold_func_brackets=True) == \ r"\sin {2 x^{2}}" assert latex(sin(x**2), fold_func_brackets=True) == \ r"\sin {x^{2}}" assert latex(asin(x)**2) == r"\operatorname{asin}^{2}{\left (x \right )}" assert latex(asin(x)**2, inv_trig_style="full") == \ r"\arcsin^{2}{\left (x \right )}" assert latex(asin(x)**2, inv_trig_style="power") == \ r"\sin^{-1}{\left (x \right )}^{2}" assert latex(asin(x**2), inv_trig_style="power", fold_func_brackets=True) == \ r"\sin^{-1} {x^{2}}" assert latex(factorial(k)) == r"k!" assert latex(factorial(-k)) == r"\left(- k\right)!" assert latex(subfactorial(k)) == r"!k" assert latex(subfactorial(-k)) == r"!\left(- k\right)" assert latex(factorial2(k)) == r"k!!" assert latex(factorial2(-k)) == r"\left(- k\right)!!" assert latex(binomial(2, k)) == r"{\binom{2}{k}}" assert latex(FallingFactorial(3, k)) == r"{\left(3\right)}_{\left(k\right)}" assert latex(RisingFactorial(3, k)) == r"{\left(3\right)}^{\left(k\right)}" assert latex(floor(x)) == r"\lfloor{x}\rfloor" assert latex(ceiling(x)) == r"\lceil{x}\rceil" assert latex(Min(x, 2, x**3)) == r"\min\left(2, x, x^{3}\right)" assert latex(Min(x, y)**2) == r"\min\left(x, y\right)^{2}" assert latex(Max(x, 2, x**3)) == r"\max\left(2, x, x^{3}\right)" assert latex(Max(x, y)**2) == r"\max\left(x, y\right)^{2}" assert latex(Abs(x)) == r"\left\lvert{x}\right\rvert" assert latex(re(x)) == r"\Re{x}" assert latex(re(x + y)) == r"\Re{x} + \Re{y}" assert latex(im(x)) == r"\Im{x}" assert latex(conjugate(x)) == r"\overline{x}" assert latex(gamma(x)) == r"\Gamma{\left(x \right)}" w = Wild('w') assert latex(gamma(w)) == r"\Gamma{\left(w \right)}" assert latex(Order(x)) == r"\mathcal{O}\left(x\right)" assert latex(Order(x, x)) == r"\mathcal{O}\left(x\right)" assert latex(Order(x, x, 0)) == r"\mathcal{O}\left(x\right)" assert latex(Order(x, x, oo)) == r"\mathcal{O}\left(x; x\rightarrow\infty\right)" assert latex( Order(x, x, y) ) == r"\mathcal{O}\left(x; \begin{pmatrix}x, & y\end{pmatrix}\rightarrow0\right)" assert latex( Order(x, x, y, 0) ) == r"\mathcal{O}\left(x; \begin{pmatrix}x, & y\end{pmatrix}\rightarrow0\right)" assert latex( Order(x, x, y, oo) ) == r"\mathcal{O}\left(x; \begin{pmatrix}x, & y\end{pmatrix}\rightarrow\infty\right)" assert latex(lowergamma(x, y)) == r'\gamma\left(x, y\right)' assert latex(uppergamma(x, y)) == r'\Gamma\left(x, y\right)' assert latex(cot(x)) == r'\cot{\left (x \right )}' assert latex(coth(x)) == r'\coth{\left (x \right )}' assert latex(re(x)) == r'\Re{x}' assert latex(im(x)) == r'\Im{x}' assert latex(root(x, y)) == r'x^{\frac{1}{y}}' assert latex(arg(x)) == r'\arg{\left (x \right )}' assert latex(zeta(x)) == r'\zeta\left(x\right)' assert latex(zeta(x)) == r"\zeta\left(x\right)" assert latex(zeta(x)**2) == r"\zeta^{2}\left(x\right)" assert latex(zeta(x, y)) == r"\zeta\left(x, y\right)" assert latex(zeta(x, y)**2) == r"\zeta^{2}\left(x, y\right)" assert latex(dirichlet_eta(x)) == r"\eta\left(x\right)" assert latex(dirichlet_eta(x)**2) == r"\eta^{2}\left(x\right)" assert latex(polylog(x, y)) == r"\operatorname{Li}_{x}\left(y\right)" assert latex(polylog(x, y)**2) == r"\operatorname{Li}_{x}^{2}\left(y\right)" assert latex(lerchphi(x, y, n)) == r"\Phi\left(x, y, n\right)" assert latex(lerchphi(x, y, n)**2) == r"\Phi^{2}\left(x, y, n\right)" assert latex(elliptic_k(z)) == r"K\left(z\right)" assert latex(elliptic_k(z)**2) == r"K^{2}\left(z\right)" assert latex(elliptic_f(x, y)) == r"F\left(x\middle| y\right)" assert latex(elliptic_f(x, y)**2) == r"F^{2}\left(x\middle| y\right)" assert latex(elliptic_e(x, y)) == r"E\left(x\middle| y\right)" assert latex(elliptic_e(x, y)**2) == r"E^{2}\left(x\middle| y\right)" assert latex(elliptic_e(z)) == r"E\left(z\right)" assert latex(elliptic_e(z)**2) == r"E^{2}\left(z\right)" assert latex(elliptic_pi(x, y, z)) == r"\Pi\left(x; y\middle| z\right)" assert latex(elliptic_pi(x, y, z)**2) == \ r"\Pi^{2}\left(x; y\middle| z\right)" assert latex(elliptic_pi(x, y)) == r"\Pi\left(x\middle| y\right)" assert latex(elliptic_pi(x, y)**2) == r"\Pi^{2}\left(x\middle| y\right)" assert latex(Ei(x)) == r'\operatorname{Ei}{\left (x \right )}' assert latex(Ei(x)**2) == r'\operatorname{Ei}^{2}{\left (x \right )}' assert latex(expint(x, y)**2) == r'\operatorname{E}_{x}^{2}\left(y\right)' assert latex(Shi(x)**2) == r'\operatorname{Shi}^{2}{\left (x \right )}' assert latex(Si(x)**2) == r'\operatorname{Si}^{2}{\left (x \right )}' assert latex(Ci(x)**2) == r'\operatorname{Ci}^{2}{\left (x \right )}' assert latex(Chi(x)**2) == r'\operatorname{Chi}^{2}{\left (x \right )}' assert latex(Chi(x)) == r'\operatorname{Chi}{\left (x \right )}' assert latex(jacobi(n, a, b, x)) == r'P_{n}^{\left(a,b\right)}\left(x\right)' assert latex(jacobi( n, a, b, x)**2) == r'\left(P_{n}^{\left(a,b\right)}\left(x\right)\right)^{2}' assert latex(gegenbauer(n, a, x)) == r'C_{n}^{\left(a\right)}\left(x\right)' assert latex(gegenbauer( n, a, x)**2) == r'\left(C_{n}^{\left(a\right)}\left(x\right)\right)^{2}' assert latex(chebyshevt(n, x)) == r'T_{n}\left(x\right)' assert latex(chebyshevt(n, x)**2) == r'\left(T_{n}\left(x\right)\right)^{2}' assert latex(chebyshevu(n, x)) == r'U_{n}\left(x\right)' assert latex(chebyshevu(n, x)**2) == r'\left(U_{n}\left(x\right)\right)^{2}' assert latex(legendre(n, x)) == r'P_{n}\left(x\right)' assert latex(legendre(n, x)**2) == r'\left(P_{n}\left(x\right)\right)^{2}' assert latex(assoc_legendre(n, a, x)) == r'P_{n}^{\left(a\right)}\left(x\right)' assert latex(assoc_legendre( n, a, x)**2) == r'\left(P_{n}^{\left(a\right)}\left(x\right)\right)^{2}' assert latex(laguerre(n, x)) == r'L_{n}\left(x\right)' assert latex(laguerre(n, x)**2) == r'\left(L_{n}\left(x\right)\right)^{2}' assert latex(assoc_laguerre(n, a, x)) == r'L_{n}^{\left(a\right)}\left(x\right)' assert latex(assoc_laguerre( n, a, x)**2) == r'\left(L_{n}^{\left(a\right)}\left(x\right)\right)^{2}' assert latex(hermite(n, x)) == r'H_{n}\left(x\right)' assert latex(hermite(n, x)**2) == r'\left(H_{n}\left(x\right)\right)^{2}' theta = Symbol("theta", real=True) phi = Symbol("phi", real=True) assert latex(Ynm(n, m, theta, phi)) == r'Y_{n}^{m}\left(\theta,\phi\right)' assert latex( Ynm(n, m, theta, phi)**3) == r'\left(Y_{n}^{m}\left(\theta,\phi\right)\right)^{3}' assert latex(Znm(n, m, theta, phi)) == r'Z_{n}^{m}\left(\theta,\phi\right)' assert latex( Znm(n, m, theta, phi)**3) == r'\left(Z_{n}^{m}\left(\theta,\phi\right)\right)^{3}' # Test latex printing of function names with "_" assert latex( polar_lift(0)) == r"\operatorname{polar\_lift}{\left (0 \right )}" assert latex(polar_lift(0)** 3) == r"\operatorname{polar\_lift}^{3}{\left (0 \right )}" assert latex(totient(n)) == r'\phi\left( n \right)' # some unknown function name should get rendered with \operatorname fjlkd = Function('fjlkd') assert latex(fjlkd(x)) == r'\operatorname{fjlkd}{\left (x \right )}' # even when it is referred to without an argument assert latex(fjlkd) == r'\operatorname{fjlkd}'
def test_si(): assert Si(I * x) == I * Shi(x) assert Shi(I * x) == I * Si(x) assert Si(-I * x) == -I * Shi(x) assert Shi(-I * x) == -I * Si(x) assert Si(-x) == -Si(x) assert Shi(-x) == -Shi(x) assert Si(exp_polar(2 * pi * I) * x) == Si(x) assert Si(exp_polar(-2 * pi * I) * x) == Si(x) assert Shi(exp_polar(2 * pi * I) * x) == Shi(x) assert Shi(exp_polar(-2 * pi * I) * x) == Shi(x) assert mytd(Si(x), sin(x) / x, x) assert mytd(Shi(x), sinh(x) / x, x) assert mytn(Si(x), Si(x).rewrite(Ei), -I*(-Ei(x*exp_polar(-I*pi/2))/2 \ + Ei(x*exp_polar(I*pi/2))/2 - I*pi) + pi/2, x) assert mytn(Si(x), Si(x).rewrite(expint), -I*(-expint(1, x*exp_polar(-I*pi/2))/2 + \ expint(1, x*exp_polar(I*pi/2))/2) + pi/2, x) assert mytn(Shi(x), Shi(x).rewrite(Ei), Ei(x) / 2 - Ei(x * exp_polar(I * pi)) / 2 + I * pi / 2, x) assert mytn( Shi(x), Shi(x).rewrite(expint), expint(1, x) / 2 - expint(1, x * exp_polar(I * pi)) / 2 - I * pi / 2, x) assert tn_arg(Si) assert tn_arg(Shi) from sympy import O assert Si(x).nseries( x, n=8) == x - x**3 / 18 + x**5 / 600 - x**7 / 35280 + O(x**9) assert Shi(x).nseries( x, n=8) == x + x**3 / 18 + x**5 / 600 + x**7 / 35280 + O(x**9) assert Si(sin(x)).nseries( x, n=5) == x - 2 * x**3 / 9 + 17 * x**5 / 450 + O(x**6) assert Si(x).nseries( x, 1, n=3) == Si(1) + x * sin(1) + x**2 * (-sin(1) / 2 + cos(1) / 2) + O(x** 3)
def test_expint(): assert mytn( expint(x, y), expint(x, y).rewrite(uppergamma), y**(x - 1) * uppergamma(1 - x, y), x, ) assert mytd(expint(x, y), -(y**(x - 1)) * meijerg([], [1, 1], [0, 0, 1 - x], [], y), x) assert mytd(expint(x, y), -expint(x - 1, y), y) assert mytn(expint(1, x), expint(1, x).rewrite(Ei), -Ei(x * polar_lift(-1)) + I * pi, x) assert (expint(-4, x) == exp(-x) / x + 4 * exp(-x) / x**2 + 12 * exp(-x) / x**3 + 24 * exp(-x) / x**4 + 24 * exp(-x) / x**5) assert expint( Rational(-3, 2), x) == exp(-x) / x + 3 * exp(-x) / (2 * x**2) + 3 * sqrt(pi) * erfc( sqrt(x)) / (4 * x**S("5/2")) assert tn_branch(expint, 1) assert tn_branch(expint, 2) assert tn_branch(expint, 3) assert tn_branch(expint, 1.7) assert tn_branch(expint, pi) assert expint( y, x * exp_polar(2 * I * pi) ) == x**(y - 1) * (exp(2 * I * pi * y) - 1) * gamma(-y + 1) + expint(y, x) assert expint(y, x * exp_polar(-2 * I * pi)) == x**(y - 1) * ( exp(-2 * I * pi * y) - 1) * gamma(-y + 1) + expint(y, x) assert expint(2, x * exp_polar(2 * I * pi)) == 2 * I * pi * x + expint(2, x) assert expint(2, x * exp_polar(-2 * I * pi)) == -2 * I * pi * x + expint(2, x) assert expint(1, x).rewrite(Ei).rewrite(expint) == expint(1, x) assert expint(x, y).rewrite(Ei) == expint(x, y) assert expint(x, y).rewrite(Ci) == expint(x, y) assert mytn(E1(x), E1(x).rewrite(Shi), Shi(x) - Chi(x), x) assert mytn( E1(polar_lift(I) * x), E1(polar_lift(I) * x).rewrite(Si), -Ci(x) + I * Si(x) - I * pi / 2, x, ) assert mytn(expint(2, x), expint(2, x).rewrite(Ei).rewrite(expint), -x * E1(x) + exp(-x), x) assert mytn( expint(3, x), expint(3, x).rewrite(Ei).rewrite(expint), x**2 * E1(x) / 2 + (1 - x) * exp(-x) / 2, x, ) assert expint(Rational(3, 2), z).nseries( z ) == 2 + 2 * z - z**2 / 3 + z**3 / 15 - z**4 / 84 + z**5 / 540 - 2 * sqrt( pi) * sqrt(z) + O(z**6) assert E1(z).series(z) == -EulerGamma - log( z) + z - z**2 / 4 + z**3 / 18 - z**4 / 96 + z**5 / 600 + O(z**6) assert expint(4, z).series(z) == Rational(1, 3) - z / 2 + z**2 / 2 + z**3 * ( log(z) / 6 - Rational(11, 36) + EulerGamma / 6 - I * pi / 6) - z**4 / 24 + z**5 / 240 + O(z**6) assert expint(z, y).series(z, 0, 2) == exp(-y) / y - z * meijerg( ((), (1, 1)), ((0, 0, 1), ()), y) / y + O(z**2) raises(ArgumentIndexError, lambda: expint(x, y).fdiff(3)) neg = Symbol("neg", negative=True) assert Ei(neg).rewrite(Si) == Shi(neg) + Chi(neg) - I * pi