def test_K(): assert K(0) == pi/2 assert K(Rational(1, 2)) == 8*pi**Rational(3, 2)/gamma(-Rational(1, 4))**2 assert K(1) == zoo assert K(-1) == gamma(Rational(1, 4))**2/(4*sqrt(2*pi)) assert K(oo) == 0 assert K(-oo) == 0 assert K(I*oo) == 0 assert K(-I*oo) == 0 assert K(zoo) == 0 assert K(z).diff(z) == (E(z) - (1 - z)*K(z))/(2*z*(1 - z)) assert td(K(z), z) pytest.raises(ArgumentIndexError, lambda: K(z).fdiff(2)) zi = Symbol('z', extended_real=False) assert K(zi).conjugate() == K(zi.conjugate()) zr = Symbol('z', extended_real=True, negative=True) assert K(zr).conjugate() == K(zr) assert K(z).rewrite(hyper) == \ (pi/2)*hyper((S.Half, S.Half), (S.One,), z) assert tn(K(z), (pi/2)*hyper((S.Half, S.Half), (S.One,), z)) assert K(z).rewrite(meijerg) == \ meijerg(((S.Half, S.Half), []), ((S.Zero,), (S.Zero,)), -z)/2 assert tn(K(z), meijerg(((S.Half, S.Half), []), ((S.Zero,), (S.Zero,)), -z)/2) assert K(z).series(z) == pi/2 + pi*z/8 + 9*pi*z**2/128 + \ 25*pi*z**3/512 + 1225*pi*z**4/32768 + 3969*pi*z**5/131072 + O(z**6)
def can_do(ap, bq, numerical=True, div=1, lowerplane=False): from diofant import exp_polar, exp r = hyperexpand(hyper(ap, bq, z)) if r.has(hyper): return False if not numerical: return True repl = {} randsyms = r.free_symbols - {z} while randsyms: # Only randomly generated parameters are checked. for n, a in enumerate(randsyms): repl[a] = randcplx(n) / div if not any(b.is_Integer and b <= 0 for b in Tuple(*bq).subs(repl)): break [a, b, c, d] = [2, -1, 3, 1] if lowerplane: [a, b, c, d] = [2, -2, 3, -1] return tn(hyper(ap, bq, z).subs(repl), r.replace(exp_polar, exp).subs(repl), z, a=a, b=b, c=c, d=d)
def test_plan(): assert devise_plan(Hyper_Function([0], ()), Hyper_Function([0], ()), z) == [] with pytest.raises(ValueError): devise_plan(Hyper_Function([1], ()), Hyper_Function((), ()), z) with pytest.raises(ValueError): devise_plan(Hyper_Function([2], [1]), Hyper_Function([2], [2]), z) with pytest.raises(ValueError): devise_plan(Hyper_Function([2], []), Hyper_Function([Rational(1, 2)], []), z) # We cannot use pi/(10000 + n) because polys is insanely slow. a1, a2, b1 = (randcplx(n) for n in range(3)) b1 += 2*I h = hyper([a1, a2], [b1], z) h2 = hyper((a1 + 1, a2), [b1], z) assert tn(apply_operators(h, devise_plan(Hyper_Function((a1 + 1, a2), [b1]), Hyper_Function((a1, a2), [b1]), z), op), h2, z) h2 = hyper((a1 + 1, a2 - 1), [b1], z) assert tn(apply_operators(h, devise_plan(Hyper_Function((a1 + 1, a2 - 1), [b1]), Hyper_Function((a1, a2), [b1]), z), op), h2, z)
def test_reduction_operators(): a1, a2, b1 = (randcplx(n) for n in range(3)) h = hyper([a1], [b1], z) assert ReduceOrder(2, 0) is None assert ReduceOrder(2, -1) is None assert ReduceOrder(1, Rational(1, 2)) is None h2 = hyper((a1, a2), (b1, a2), z) assert tn(ReduceOrder(a2, a2).apply(h, op), h2, z) assert str(ReduceOrder(a2, a2)).find('<Reduce order by cancelling upper ') == 0 h2 = hyper((a1, a2 + 1), (b1, a2), z) assert tn(ReduceOrder(a2 + 1, a2).apply(h, op), h2, z) h2 = hyper((a2 + 4, a1), (b1, a2), z) assert tn(ReduceOrder(a2 + 4, a2).apply(h, op), h2, z) # test several step order reduction ap = (a2 + 4, a1, b1 + 1) bq = (a2, b1, b1) func, ops = reduce_order(Hyper_Function(ap, bq)) assert func.ap == (a1, ) assert func.bq == (b1, ) assert tn(apply_operators(h, ops, op), hyper(ap, bq, z), z)
def test_plan(): assert devise_plan(Hyper_Function([0], ()), Hyper_Function([0], ()), z) == [] with pytest.raises(ValueError): devise_plan(Hyper_Function([1], ()), Hyper_Function((), ()), z) with pytest.raises(ValueError): devise_plan(Hyper_Function([2], [1]), Hyper_Function([2], [2]), z) with pytest.raises(ValueError): devise_plan(Hyper_Function([2], []), Hyper_Function([Rational(1, 2)], []), z) # We cannot use pi/(10000 + n) because polys is insanely slow. a1, a2, b1 = (randcplx(n) for n in range(3)) b1 += 2*I h = hyper([a1, a2], [b1], z) h2 = hyper((a1 + 1, a2), [b1], z) assert tn(apply_operators(h, devise_plan(Hyper_Function((a1 + 1, a2), [b1]), Hyper_Function((a1, a2), [b1]), z), op), h2, z) h2 = hyper((a1 + 1, a2 - 1), [b1], z) assert tn(apply_operators(h, devise_plan(Hyper_Function((a1 + 1, a2 - 1), [b1]), Hyper_Function((a1, a2), [b1]), z), op), h2, z)
def test_hyper_unpolarify(): a = exp_polar(2 * pi * I) * x b = x assert hyper([], [], a).argument == b assert hyper([0], [], a).argument == a assert hyper([0], [0], a).argument == b assert hyper([0, 1], [0], a).argument == a
def test_polynomial(): from diofant import oo assert hyperexpand(hyper([], [-1], z)) == oo assert hyperexpand(hyper([-2], [-1], z)) == oo assert hyperexpand(hyper([0, 0], [-1], z)) == 1 assert can_do([-5, -2, randcplx(), randcplx()], [-10, randcplx()]) assert hyperexpand(hyper((-1, 1), (-2, ), z)) == 1 + z / 2
def test_hyper_unpolarify(): a = exp_polar(2*pi*I)*x b = x assert hyper([], [], a).argument == b assert hyper([0], [], a).argument == a assert hyper([0], [0], a).argument == b assert hyper([0, 1], [0], a).argument == a
def test_hyper_unpolarify(): from diofant import exp_polar a = exp_polar(2 * pi * I) * x b = x assert hyper([], [], a).argument == b assert hyper([0], [], a).argument == a assert hyper([0], [0], a).argument == b assert hyper([0, 1], [0], a).argument == a
def test_hyper_rewrite_sum(): _k = Dummy("k") assert replace_dummy(hyper((1, 2), (1, 3), x).rewrite(Sum), _k) == \ Sum(x**_k / factorial(_k) * RisingFactorial(2, _k) / RisingFactorial(3, _k), (_k, 0, oo)) assert hyper((1, 2, 3), (-1, 3), z).rewrite(Sum) == \ hyper((1, 2, 3), (-1, 3), z)
def test_hyper_rewrite_sum(): _k = Dummy("k") assert replace_dummy(hyper((1, 2), (1, 3), x).rewrite(Sum), _k) == \ Sum(x**_k / factorial(_k) * RisingFactorial(2, _k) / RisingFactorial(3, _k), (_k, 0, oo)) assert hyper((1, 2, 3), (-1, 3), z).rewrite(Sum) == \ hyper((1, 2, 3), (-1, 3), z)
def test_limits(): k, x = symbols('k, x') assert hyper((1,), (Rational(4, 3), Rational(5, 3)), k**2).series(k) == \ hyper((1,), (Rational(4, 3), Rational(5, 3)), 0) + \ 9*k**2*hyper((2,), (Rational(7, 3), Rational(8, 3)), 0)/20 + \ 81*k**4*hyper((3,), (Rational(10, 3), Rational(11, 3)), 0)/1120 + \ O(k**6) # issue sympy/sympy#6350 assert limit(meijerg((), (), (1,), (0,), -x), x, 0) == \ meijerg(((), ()), ((1,), (0,)), 0) # issue sympy/sympy#6052
def test_limits(): k, x = symbols('k, x') assert hyper((1,), (Rational(4, 3), Rational(5, 3)), k**2).series(k) == \ hyper((1,), (Rational(4, 3), Rational(5, 3)), 0) + \ 9*k**2*hyper((2,), (Rational(7, 3), Rational(8, 3)), 0)/20 + \ 81*k**4*hyper((3,), (Rational(10, 3), Rational(11, 3)), 0)/1120 + \ O(k**6) # issue sympy/sympy#6350 assert limit(meijerg((), (), (1,), (0,), -x), x, 0) == \ meijerg(((), ()), ((1,), (0,)), 0) # issue sympy/sympy#6052
def test_hyperexpand(): # Luke, Y. L. (1969), The Special Functions and Their Approximations, # Volume 1, section 6.2 assert hyperexpand(hyper([], [], z)) == exp(z) assert hyperexpand(hyper([1, 1], [2], -z)*z) == log(1 + z) assert hyperexpand(hyper([], [S.Half], -z**2/4)) == cos(z) assert hyperexpand(z*hyper([], [Rational(3, 2)], -z**2/4)) == sin(z) assert hyperexpand(hyper([Rational(1, 2), Rational(1, 2)], [Rational(3, 2)], z**2)*z) \ == asin(z)
def test_hyperexpand(): # Luke, Y. L. (1969), The Special Functions and Their Approximations, # Volume 1, section 6.2 assert hyperexpand(hyper([], [], z)) == exp(z) assert hyperexpand(hyper([1, 1], [2], -z)*z) == log(1 + z) assert hyperexpand(hyper([], [Rational(1, 2)], -z**2/4)) == cos(z) assert hyperexpand(z*hyper([], [Rational(3, 2)], -z**2/4)) == sin(z) assert hyperexpand(hyper([Rational(1, 2), Rational(1, 2)], [Rational(3, 2)], z**2)*z) \ == asin(z)
def test_airybi(): z = Symbol('z', extended_real=False) t = Symbol('t', negative=True) p = Symbol('p', positive=True) assert isinstance(airybi(z), airybi) assert airybi(0) == 3**Rational(5, 6) / (3 * gamma(Rational(2, 3))) assert airybi(oo) == oo assert airybi(-oo) == 0 assert diff(airybi(z), z) == airybiprime(z) assert series(airybi(z), z, 0, 3) == (cbrt(3) * gamma(Rational(1, 3)) / (2 * pi) + 3**Rational(2, 3) * z * gamma(Rational(2, 3)) / (2 * pi) + O(z**3)) l = Limit( airybi(I / x) / (exp(Rational(2, 3) * (I / x)**Rational(3, 2)) * sqrt(pi * sqrt(I / x))), x, 0) assert l.doit() == l assert airybi(z).rewrite(hyper) == (root(3, 6) * z * hyper( (), (Rational(4, 3), ), z**3 / 9) / gamma(Rational(1, 3)) + 3**Rational(5, 6) * hyper( (), (Rational(2, 3), ), z**3 / 9) / (3 * gamma(Rational(2, 3)))) assert isinstance(airybi(z).rewrite(besselj), airybi) assert (airybi(t).rewrite(besselj) == sqrt(3) * sqrt(-t) * (besselj(-1 / 3, 2 * (-t)**Rational(3, 2) / 3) - besselj(Rational(1, 3), 2 * (-t)**Rational(3, 2) / 3)) / 3) assert airybi(z).rewrite(besseli) == ( sqrt(3) * (z * besseli(Rational(1, 3), 2 * z**Rational(3, 2) / 3) / cbrt(z**Rational(3, 2)) + cbrt(z**Rational(3, 2)) * besseli(-Rational(1, 3), 2 * z**Rational(3, 2) / 3)) / 3) assert airybi(p).rewrite(besseli) == ( sqrt(3) * sqrt(p) * (besseli(-Rational(1, 3), 2 * p**Rational(3, 2) / 3) + besseli(Rational(1, 3), 2 * p**Rational(3, 2) / 3)) / 3) assert airybi(p).rewrite(besselj) == airybi(p) assert expand_func(airybi( 2 * cbrt(3 * z**5))) == (sqrt(3) * (1 - cbrt(z**5) / z**Rational(5, 3)) * airyai(2 * cbrt(3) * z**Rational(5, 3)) / 2 + (1 + cbrt(z**5) / z**Rational(5, 3)) * airybi(2 * cbrt(3) * z**Rational(5, 3)) / 2) assert expand_func(airybi(x * y)) == airybi(x * y) assert expand_func(airybi(log(x))) == airybi(log(x)) assert expand_func(airybi(2 * root(3 * z**5, 5))) == airybi( 2 * root(3 * z**5, 5)) assert airybi(x).taylor_term(-1, x) == 0
def test_hyperexpand_special(): assert hyperexpand(hyper([a, b], [c], 1)) == \ gamma(c)*gamma(c - a - b)/gamma(c - a)/gamma(c - b) assert hyperexpand(hyper([a, b], [1 + a - b], -1)) == \ gamma(1 + a/2)*gamma(1 + a - b)/gamma(1 + a)/gamma(1 + a/2 - b) assert hyperexpand(hyper([a, b], [1 + b - a], -1)) == \ gamma(1 + b/2)*gamma(1 + b - a)/gamma(1 + b)/gamma(1 + b/2 - a) assert hyperexpand(meijerg([1 - z - a/2], [1 - z + a/2], [b/2], [-b/2], 1)) == \ gamma(1 - 2*z)*gamma(z + a/2 + b/2)/gamma(1 - z + a/2 - b/2) \ / gamma(1 - z - a/2 + b/2)/gamma(1 - z + a/2 + b/2) assert hyperexpand(hyper([a], [b], 0)) == 1 assert hyper([a], [b], 0) != 0
def test_hyperexpand_special(): assert hyperexpand(hyper([a, b], [c], 1)) == \ gamma(c)*gamma(c - a - b)/gamma(c - a)/gamma(c - b) assert hyperexpand(hyper([a, b], [1 + a - b], -1)) == \ gamma(1 + a/2)*gamma(1 + a - b)/gamma(1 + a)/gamma(1 + a/2 - b) assert hyperexpand(hyper([a, b], [1 + b - a], -1)) == \ gamma(1 + b/2)*gamma(1 + b - a)/gamma(1 + b)/gamma(1 + b/2 - a) assert hyperexpand(meijerg([1 - z - a/2], [1 - z + a/2], [b/2], [-b/2], 1)) == \ gamma(1 - 2*z)*gamma(z + a/2 + b/2)/gamma(1 - z + a/2 - b/2) \ / gamma(1 - z - a/2 + b/2)/gamma(1 - z + a/2 + b/2) assert hyperexpand(hyper([a], [b], 0)) == 1 assert hyper([a], [b], 0) != 0
def test_airyai(): z = Symbol('z', extended_real=False) r = Symbol('r', extended_real=True) t = Symbol('t', negative=True) p = Symbol('p', positive=True) assert isinstance(airyai(z), airyai) assert airyai(0) == cbrt(3)/(3*gamma(Rational(2, 3))) assert airyai(oo) == 0 assert airyai(-oo) == 0 assert diff(airyai(z), z) == airyaiprime(z) assert airyai(z).series(z, 0, 3) == ( 3**Rational(5, 6)*gamma(Rational(1, 3))/(6*pi) - root(3, 6)*z*gamma(Rational(2, 3))/(2*pi) + O(z**3)) l = Limit(airyai(I/x)/(exp(-Rational(2, 3)*(I/x)**Rational(3, 2))*sqrt(pi*sqrt(I/x))/2), x, 0) assert l.doit() == l # cover _airyais._eval_aseries assert airyai(z).rewrite(hyper) == ( -3**Rational(2, 3)*z*hyper((), (Rational(4, 3),), z**3/9)/(3*gamma(Rational(1, 3))) + cbrt(3)*hyper((), (Rational(2, 3),), z**3/9)/(3*gamma(Rational(2, 3)))) assert isinstance(airyai(z).rewrite(besselj), airyai) assert airyai(t).rewrite(besselj) == ( sqrt(-t)*(besselj(-Rational(1, 3), 2*(-t)**Rational(3, 2)/3) + besselj(Rational(1, 3), 2*(-t)**Rational(3, 2)/3))/3) assert airyai(z).rewrite(besseli) == ( -z*besseli(Rational(1, 3), 2*z**Rational(3, 2)/3)/(3*cbrt(z**Rational(3, 2))) + cbrt(z**Rational(3, 2))*besseli(-Rational(1, 3), 2*z**Rational(3, 2)/3)/3) assert airyai(p).rewrite(besseli) == ( sqrt(p)*(besseli(-Rational(1, 3), 2*p**Rational(3, 2)/3) - besseli(Rational(1, 3), 2*p**Rational(3, 2)/3))/3) assert expand_func(airyai(2*cbrt(3*z**5))) == ( -sqrt(3)*(-1 + cbrt(z**5)/z**Rational(5, 3))*airybi(2*cbrt(3)*z**Rational(5, 3))/6 + (1 + cbrt(z**5)/z**Rational(5, 3))*airyai(2*cbrt(3)*z**Rational(5, 3))/2) assert expand_func(airyai(x*y)) == airyai(x*y) assert expand_func(airyai(log(x))) == airyai(log(x)) assert expand_func(airyai(2*root(3*z**5, 5))) == airyai(2*root(3*z**5, 5)) assert (airyai(r).as_real_imag() == airyai(r).as_real_imag(deep=False) == (airyai(r), 0)) assert airyai(x).as_real_imag() == airyai(x).as_real_imag(deep=False) assert (airyai(x).as_real_imag() == (airyai(re(x) - I*re(x)*abs(im(x))/abs(re(x)))/2 + airyai(re(x) + I*re(x)*abs(im(x))/abs(re(x)))/2, I*(airyai(re(x) - I*re(x)*abs(im(x))/abs(re(x))) - airyai(re(x) + I*re(x)*abs(im(x))/abs(re(x)))) * re(x)*abs(im(x))/(2*im(x)*abs(re(x))))) assert airyai(x).taylor_term(-1, x) == 0
def test_airyai(): z = Symbol('z', extended_real=False) r = Symbol('r', extended_real=True) t = Symbol('t', negative=True) p = Symbol('p', positive=True) assert isinstance(airyai(z), airyai) assert airyai(0) == cbrt(3)/(3*gamma(Rational(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**Rational(5, 6)*gamma(Rational(1, 3))/(6*pi) - root(3, 6)*z*gamma(Rational(2, 3))/(2*pi) + O(z**3)) l = Limit(airyai(I/x)/(exp(-Rational(2, 3)*(I/x)**Rational(3, 2))*sqrt(pi*sqrt(I/x))/2), x, 0) assert l.doit() == l # cover _airyais._eval_aseries assert airyai(z).rewrite(hyper) == ( -3**Rational(2, 3)*z*hyper((), (Rational(4, 3),), z**3/9)/(3*gamma(Rational(1, 3))) + cbrt(3)*hyper((), (Rational(2, 3),), z**3/9)/(3*gamma(Rational(2, 3)))) assert isinstance(airyai(z).rewrite(besselj), airyai) assert airyai(t).rewrite(besselj) == ( sqrt(-t)*(besselj(-Rational(1, 3), 2*(-t)**Rational(3, 2)/3) + besselj(Rational(1, 3), 2*(-t)**Rational(3, 2)/3))/3) assert airyai(z).rewrite(besseli) == ( -z*besseli(Rational(1, 3), 2*z**Rational(3, 2)/3)/(3*cbrt(z**Rational(3, 2))) + cbrt(z**Rational(3, 2))*besseli(-Rational(1, 3), 2*z**Rational(3, 2)/3)/3) assert airyai(p).rewrite(besseli) == ( sqrt(p)*(besseli(-Rational(1, 3), 2*p**Rational(3, 2)/3) - besseli(Rational(1, 3), 2*p**Rational(3, 2)/3))/3) assert expand_func(airyai(2*cbrt(3*z**5))) == ( -sqrt(3)*(-1 + cbrt(z**5)/z**Rational(5, 3))*airybi(2*cbrt(3)*z**Rational(5, 3))/6 + (1 + cbrt(z**5)/z**Rational(5, 3))*airyai(2*cbrt(3)*z**Rational(5, 3))/2) assert expand_func(airyai(x*y)) == airyai(x*y) assert expand_func(airyai(log(x))) == airyai(log(x)) assert expand_func(airyai(2*root(3*z**5, 5))) == airyai(2*root(3*z**5, 5)) assert (airyai(r).as_real_imag() == airyai(r).as_real_imag(deep=False) == (airyai(r), 0)) assert airyai(x).as_real_imag() == airyai(x).as_real_imag(deep=False) assert (airyai(x).as_real_imag() == (airyai(re(x) - I*re(x)*abs(im(x))/abs(re(x)))/2 + airyai(re(x) + I*re(x)*abs(im(x))/abs(re(x)))/2, I*(airyai(re(x) - I*re(x)*abs(im(x))/abs(re(x))) - airyai(re(x) + I*re(x)*abs(im(x))/Abs(re(x)))) * re(x)*abs(im(x))/(2*im(x)*abs(re(x))))) assert airyai(x).taylor_term(-1, x) == 0
def test_elliptic_e(): assert elliptic_e(z, 0) == z assert elliptic_e(0, m) == 0 assert elliptic_e(i * pi / 2, m) == i * elliptic_e(m) assert elliptic_e(z, oo) == zoo assert elliptic_e(z, -oo) == zoo assert elliptic_e(0) == pi / 2 assert elliptic_e(1) == 1 assert elliptic_e(oo) == I * oo assert elliptic_e(-oo) == oo assert elliptic_e(zoo) == zoo assert elliptic_e(-z, m) == -elliptic_e(z, m) assert elliptic_e(z, m).diff(z) == sqrt(1 - m * sin(z)**2) assert elliptic_e( z, m).diff(m) == (elliptic_e(z, m) - elliptic_f(z, m)) / (2 * m) assert elliptic_e(z).diff(z) == (elliptic_e(z) - elliptic_k(z)) / (2 * z) r = randcplx() assert td(elliptic_e(r, m), m) assert td(elliptic_e(z, r), z) assert td(elliptic_e(z), z) pytest.raises(ArgumentIndexError, lambda: elliptic_e(z, m).fdiff(3)) pytest.raises(ArgumentIndexError, lambda: elliptic_e(z).fdiff(2)) mi = Symbol('m', extended_real=False) assert elliptic_e(z, mi).conjugate() == elliptic_e(z.conjugate(), mi.conjugate()) assert elliptic_e(mi).conjugate() == elliptic_e(mi.conjugate()) mr = Symbol('m', extended_real=True, negative=True) assert elliptic_e(z, mr).conjugate() == elliptic_e(z.conjugate(), mr) assert elliptic_e(mr).conjugate() == elliptic_e(mr) assert elliptic_e(z, m).conjugate() == conjugate(elliptic_e(z, m)) assert elliptic_e(z).conjugate() == conjugate(elliptic_e(z)) assert elliptic_e(z).rewrite(hyper) == (pi / 2) * hyper( (Rational(-1, 2), Rational(1, 2)), (1, ), z) assert elliptic_e(z, m).rewrite(hyper) == elliptic_e(z, m) assert tn(elliptic_e(z), (pi / 2) * hyper( (Rational(-1, 2), Rational(1, 2)), (1, ), z)) assert elliptic_e(z).rewrite(meijerg) == \ -meijerg(((Rational(1, 2), Rational(3, 2)), []), ((0,), (0,)), -z)/4 assert elliptic_e(z, m).rewrite(meijerg) == elliptic_e(z, m) assert tn( elliptic_e(z), -meijerg(((Rational(1, 2), Rational(3, 2)), []), ((0, ), (0, )), -z) / 4) assert elliptic_e(z, m).series(z) == \ z + z**5*(-m**2/40 + m/30) - m*z**3/6 + O(z**6) assert elliptic_e(z).series(z) == pi/2 - pi*z/8 - 3*pi*z**2/128 - \ 5*pi*z**3/512 - 175*pi*z**4/32768 - 441*pi*z**5/131072 + O(z**6)
def test_airybiprime(): z = Symbol('z', extended_real=False) t = Symbol('t', negative=True) p = Symbol('p', positive=True) assert isinstance(airybiprime(z), airybiprime) assert airybiprime(0) == root(3, 6) / gamma(Rational(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) == (root(3, 6) / gamma(Rational(1, 3)) + 3**Rational(5, 6) * z**2 / (6 * gamma(Rational(2, 3))) + O(z**3)) assert airybiprime(z).rewrite(hyper) == ( 3**Rational(5, 6) * z**2 * hyper((), (Rational(5, 3), ), z**3 / 9) / (6 * gamma(Rational(2, 3))) + root(3, 6) * hyper( (), (Rational(1, 3), ), z**3 / 9) / gamma(Rational(1, 3))) assert isinstance(airybiprime(z).rewrite(besselj), airybiprime) assert (airybiprime(t).rewrite(besselj) == -sqrt(3) * t * (besselj(-Rational(2, 3), 2 * (-t)**Rational(3, 2) / 3) + besselj(Rational(2, 3), 2 * (-t)**Rational(3, 2) / 3)) / 3) assert airybiprime(z).rewrite(besseli) == ( sqrt(3) * (z**2 * besseli(Rational(2, 3), 2 * z**Rational(3, 2) / 3) / (z**Rational(3, 2))**Rational(2, 3) + (z**Rational(3, 2))**Rational(2, 3) * besseli(-Rational(2, 3), 2 * z**Rational(3, 2) / 3)) / 3) assert airybiprime(p).rewrite(besseli) == ( sqrt(3) * p * (besseli(-Rational(2, 3), 2 * p**Rational(3, 2) / 3) + besseli(Rational(2, 3), 2 * p**Rational(3, 2) / 3)) / 3) assert airybiprime(p).rewrite(besselj) == airybiprime(p) assert expand_func(airybiprime( 2 * cbrt(3 * z**5))) == (sqrt(3) * (z**Rational(5, 3) / cbrt(z**5) - 1) * airyaiprime(2 * cbrt(3) * z**Rational(5, 3)) / 2 + (z**Rational(5, 3) / cbrt(z**5) + 1) * airybiprime(2 * cbrt(3) * z**Rational(5, 3)) / 2) assert expand_func(airybiprime(x * y)) == airybiprime(x * y) assert expand_func(airybiprime(log(x))) == airybiprime(log(x)) assert expand_func(airybiprime(2 * root(3 * z**5, 5))) == airybiprime( 2 * root(3 * z**5, 5)) assert airybiprime(-2).evalf(50) == Float( '0.27879516692116952268509756941098324140300059345163131', dps=50)
def test_airyaiprime(): z = Symbol('z', extended_real=False) t = Symbol('t', negative=True) p = Symbol('p', positive=True) assert isinstance(airyaiprime(z), airyaiprime) assert airyaiprime(0) == -3**Rational(2, 3) / (3 * gamma(Rational(1, 3))) assert airyaiprime(oo) == 0 assert diff(airyaiprime(z), z) == z * airyai(z) assert series(airyaiprime(z), z, 0, 3) == (-3**Rational(2, 3) / (3 * gamma(Rational(1, 3))) + cbrt(3) * z**2 / (6 * gamma(Rational(2, 3))) + O(z**3)) assert airyaiprime(z).rewrite(hyper) == ( cbrt(3) * z**2 * hyper((), (Rational(5, 3), ), z**3 / 9) / (6 * gamma(Rational(2, 3))) - 3**Rational(2, 3) * hyper( (), (Rational(1, 3), ), z**3 / 9) / (3 * gamma(Rational(1, 3)))) assert isinstance(airyaiprime(z).rewrite(besselj), airyaiprime) assert (airyaiprime(t).rewrite(besselj) == t * (besselj(-Rational(2, 3), 2 * (-t)**Rational(3, 2) / 3) - besselj(Rational(2, 3), 2 * (-t)**Rational(3, 2) / 3)) / 3) assert airyaiprime(z).rewrite(besseli) == ( z**2 * besseli(Rational(2, 3), 2 * z**Rational(3, 2) / 3) / (3 * (z**Rational(3, 2))**Rational(2, 3)) - (z**Rational(3, 2))**Rational(2, 3) * besseli(-Rational(1, 3), 2 * z**Rational(3, 2) / 3) / 3) assert airyaiprime(p).rewrite(besseli) == ( p * (-besseli(-Rational(2, 3), 2 * p**Rational(3, 2) / 3) + besseli(Rational(2, 3), 2 * p**Rational(3, 2) / 3)) / 3) assert airyaiprime(p).rewrite(besselj) == airyaiprime(p) assert expand_func(airyaiprime( 2 * cbrt(3 * z**5))) == (sqrt(3) * (z**Rational(5, 3) / cbrt(z**5) - 1) * airybiprime(2 * cbrt(3) * z**Rational(5, 3)) / 6 + (z**Rational(5, 3) / cbrt(z**5) + 1) * airyaiprime(2 * cbrt(3) * z**Rational(5, 3)) / 2) assert expand_func(airyaiprime(x * y)) == airyaiprime(x * y) assert expand_func(airyaiprime(log(x))) == airyaiprime(log(x)) assert expand_func(airyaiprime(2 * root(3 * z**5, 5))) == airyaiprime( 2 * root(3 * z**5, 5)) assert airyaiprime(-2).evalf(50) == Float( '0.61825902074169104140626429133247528291577794512414753', dps=50)
def test_branch_bug(): assert hyperexpand(hyper((-Rational(1, 3), Rational(1, 2)), (Rational(2, 3), Rational(3, 2)), -z)) == \ -z**Rational(1, 3)*lowergamma(exp_polar(I*pi)/3, z)/5 \ + sqrt(pi)*erf(sqrt(z))/(5*sqrt(z)) assert hyperexpand(meijerg([Rational(7, 6), 1], [], [Rational(2, 3)], [Rational(1, 6), 0], z)) == \ 2*z**Rational(2, 3)*(2*sqrt(pi)*erf(sqrt(z))/sqrt(z) - 2*lowergamma(Rational(2, 3), z)/z**Rational(2, 3))*gamma(Rational(2, 3))/gamma(Rational(5, 3))
def test_li(): z = Symbol("z") zr = Symbol("z", extended_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)))
def test_erf(): assert erf(nan) == nan assert erf(oo) == 1 assert erf(-oo) == -1 assert erf(0) == 0 assert erf(I * oo) == oo * I assert erf(-I * oo) == -oo * I assert erf(-2) == -erf(2) assert erf(-x * y) == -erf(x * y) assert erf(-x - y) == -erf(x + y) assert erf(erfinv(x)) == x assert erf(erfcinv(x)) == 1 - x assert erf(erf2inv(0, x)) == x assert erf(erf2inv(0, erf(erfcinv(1 - erf(erfinv(x)))))) == x assert erf(I).is_extended_real is False assert erf(w).is_extended_real is True assert erf(z).is_extended_real is None assert conjugate(erf(z)) == erf(conjugate(z)) assert erf(x).as_leading_term(x) == 2 * x / sqrt(pi) assert erf(1 / x).as_leading_term(x) == erf(1 / x) assert erf(z).rewrite('uppergamma') == sqrt(z**2) * erf(sqrt(z**2)) / z assert erf(z).rewrite('erfc') == S.One - erfc(z) assert erf(z).rewrite('erfi') == -I * erfi(I * z) assert erf(z).rewrite('fresnels') == (1 + I) * ( fresnelc(z * (1 - I) / sqrt(pi)) - I * fresnels(z * (1 - I) / sqrt(pi))) assert erf(z).rewrite('fresnelc') == (1 + I) * ( fresnelc(z * (1 - I) / sqrt(pi)) - I * fresnels(z * (1 - I) / sqrt(pi))) assert erf(z).rewrite('hyper') == 2 * z * hyper([S.Half], [3 * S.Half], -z**2) / sqrt(pi) assert erf(z).rewrite('meijerg') == z * meijerg([S.Half], [], [0], [-S.Half], z**2) / sqrt(pi) assert erf(z).rewrite( 'expint') == sqrt(z**2) / z - z * expint(S.Half, z**2) / sqrt(S.Pi) assert limit(exp(x)*exp(x**2)*(erf(x + 1/exp(x)) - erf(x)), x, oo) == \ 2/sqrt(pi) assert limit((1 - erf(z)) * exp(z**2) * z, z, oo) == 1 / sqrt(pi) assert limit((1 - erf(x)) * exp(x**2) * sqrt(pi) * x, x, oo) == 1 assert limit(((1 - erf(x)) * exp(x**2) * sqrt(pi) * x - 1) * 2 * x**2, x, oo) == -1 assert erf(x).as_real_imag() == \ ((erf(re(x) - I*re(x)*Abs(im(x))/Abs(re(x)))/2 + erf(re(x) + I*re(x)*Abs(im(x))/Abs(re(x)))/2, I*(erf(re(x) - I*re(x)*Abs(im(x))/Abs(re(x))) - erf(re(x) + I*re(x)*Abs(im(x))/Abs(re(x)))) * re(x)*Abs(im(x))/(2*im(x)*Abs(re(x))))) pytest.raises(ArgumentIndexError, lambda: erf(x).fdiff(2))
def test_jacobi(): assert jacobi(0, a, b, x) == 1 assert jacobi(1, a, b, x) == a / 2 - b / 2 + x * (a / 2 + b / 2 + 1) assert (jacobi(2, a, b, x) == a**2 / 8 - a * b / 4 - a / 8 + b**2 / 8 - b / 8 + x**2 * (a**2 / 8 + a * b / 4 + 7 * a / 8 + b**2 / 8 + 7 * b / 8 + Rational(3, 2)) + x * (a**2 / 4 + 3 * a / 4 - b**2 / 4 - 3 * b / 4) - S.Half) assert jacobi(n, a, a, x) == RisingFactorial(a + 1, n) * gegenbauer( n, a + Rational(1, 2), x) / RisingFactorial(2 * a + 1, n) assert jacobi(n, a, -a, x) == ((-1)**a * (-x + 1)**(-a / 2) * (x + 1)**(a / 2) * assoc_legendre(n, a, x) * factorial(-a + n) * gamma(a + n + 1) / (factorial(a + n) * gamma(n + 1))) assert jacobi(n, -b, b, x) == ((-x + 1)**(b / 2) * (x + 1)**(-b / 2) * assoc_legendre(n, b, x) * gamma(-b + n + 1) / gamma(n + 1)) assert jacobi(n, 0, 0, x) == legendre(n, x) assert jacobi(n, S.Half, S.Half, x) == RisingFactorial(Rational( 3, 2), n) * chebyshevu(n, x) / factorial(n + 1) assert jacobi(n, -S.Half, -S.Half, x) == RisingFactorial( Rational(1, 2), n) * chebyshevt(n, x) / factorial(n) X = jacobi(n, a, b, x) assert isinstance(X, jacobi) assert jacobi(n, a, b, -x) == (-1)**n * jacobi(n, b, a, x) assert jacobi(n, a, b, 0) == 2**(-n) * gamma(a + n + 1) * hyper( (-b - n, -n), (a + 1, ), -1) / (factorial(n) * gamma(a + 1)) assert jacobi(n, a, b, 1) == RisingFactorial(a + 1, n) / factorial(n) m = Symbol("m", positive=True) assert jacobi(m, a, b, oo) == oo * RisingFactorial(a + b + m + 1, m) assert conjugate(jacobi(m, a, b, x)) == \ jacobi(m, conjugate(a), conjugate(b), conjugate(x)) assert diff(jacobi(n, a, b, x), n) == Derivative(jacobi(n, a, b, x), n) assert diff(jacobi(n, a, b, x), x) == \ (a/2 + b/2 + n/2 + Rational(1, 2))*jacobi(n - 1, a + 1, b + 1, x) # XXX see issue sympy/sympy#5539 assert str(jacobi(n, a, b, x).diff(a)) == \ ("Sum((jacobi(n, a, b, x) + (a + b + 2*_k + 1)*RisingFactorial(b + " "_k + 1, n - _k)*jacobi(_k, a, b, x)/((n - _k)*RisingFactorial(a + " "b + _k + 1, n - _k)))/(a + b + n + _k + 1), (_k, 0, n - 1))") assert str(jacobi(n, a, b, x).diff(b)) == \ ("Sum(((-1)**(n - _k)*(a + b + 2*_k + 1)*RisingFactorial(a + " "_k + 1, n - _k)*jacobi(_k, a, b, x)/((n - _k)*RisingFactorial(a + " "b + _k + 1, n - _k)) + jacobi(n, a, b, x))/(a + b + n + " "_k + 1), (_k, 0, n - 1))") assert jacobi_normalized(n, a, b, x) == \ (jacobi(n, a, b, x)/sqrt(2**(a + b + 1)*gamma(a + n + 1)*gamma(b + n + 1) / ((a + b + 2*n + 1)*factorial(n)*gamma(a + b + n + 1)))) pytest.raises(ValueError, lambda: jacobi(-2.1, a, b, x)) pytest.raises(ValueError, lambda: jacobi(Dummy(positive=True, integer=True), 1, 2, oo)) pytest.raises(ArgumentIndexError, lambda: jacobi(n, a, b, x).fdiff(5))
def test_hyperexpand(): # Luke, Y. L. (1969), The Special Functions and Their Approximations, # Volume 1, section 6.2 assert hyperexpand(hyper([], [], z)) == exp(z) assert hyperexpand(hyper([1, 1], [2], -z)*z) == log(1 + z) assert hyperexpand(hyper([], [Rational(1, 2)], -z**2/4)) == cos(z) assert hyperexpand(z*hyper([], [Rational(3, 2)], -z**2/4)) == sin(z) assert hyperexpand(hyper([Rational(1, 2), Rational(1, 2)], [Rational(3, 2)], z**2)*z) \ == asin(z) # Test place option f = meijerg(((0, 1), ()), ((Rational(1, 2),), (0,)), z**2) assert hyperexpand(f) == sqrt(pi)/sqrt(1 + z**(-2)) assert hyperexpand(f, place=0) == sqrt(pi)*z/sqrt(z**2 + 1) assert hyperexpand(f, place=zoo) == sqrt(pi)/sqrt(1 + z**(-2))
def test_branch_bug(): assert hyperexpand(hyper((-Rational(1, 3), Rational(1, 2)), (Rational(2, 3), Rational(3, 2)), -z)) == \ -cbrt(z)*lowergamma(exp_polar(I*pi)/3, z)/5 \ + sqrt(pi)*erf(sqrt(z))/(5*sqrt(z)) assert hyperexpand(meijerg([Rational(7, 6), 1], [], [Rational(2, 3)], [Rational(1, 6), 0], z)) == \ 2*z**Rational(2, 3)*(2*sqrt(pi)*erf(sqrt(z))/sqrt(z) - 2*lowergamma(Rational(2, 3), z)/z**Rational(2, 3))*gamma(Rational(2, 3))/gamma(Rational(5, 3))
def test_catalan(): n = Symbol('n', integer=True) m = Symbol('n', integer=True, positive=True) catalans = [1, 1, 2, 5, 14, 42, 132, 429, 1430, 4862, 16796, 58786] for i, c in enumerate(catalans): assert catalan(i) == c assert catalan(n).rewrite(factorial).subs({n: i}) == c assert catalan(n).rewrite(Product).subs({n: i}).doit() == c assert catalan(x) == catalan(x) assert catalan(2 * x).rewrite(binomial) == binomial(4 * x, 2 * x) / (2 * x + 1) assert catalan(Rational(1, 2)).rewrite(gamma) == 8 / (3 * pi) assert catalan(Rational(1, 2)).rewrite(factorial).rewrite(gamma) ==\ 8 / (3 * pi) assert catalan(3 * x).rewrite(gamma) == 4**( 3 * x) * gamma(3 * x + Rational(1, 2)) / (sqrt(pi) * gamma(3 * x + 2)) assert catalan(x).rewrite(hyper) == hyper((-x + 1, -x), (2, ), 1) assert catalan(n).rewrite(factorial) == factorial( 2 * n) / (factorial(n + 1) * factorial(n)) assert isinstance(catalan(n).rewrite(Product), catalan) assert isinstance(catalan(m).rewrite(Product), Product) assert diff(catalan(x), x) == (polygamma(0, x + Rational(1, 2)) - polygamma(0, x + 2) + log(4)) * catalan(x) assert catalan(x).evalf() == catalan(x) c = catalan(Rational(1, 2)).evalf() assert str(c) == '0.848826363156775' c = catalan(I).evalf(3) assert sstr((re(c), im(c))) == '(0.398, -0.0209)'
def test_erfc(): assert erfc(nan) == nan assert erfc(oo) == 0 assert erfc(-oo) == 2 assert erfc(0) == 1 assert erfc(I * oo) == -oo * I assert erfc(-I * oo) == oo * I assert erfc(-x) == Integer(2) - erfc(x) assert erfc(erfcinv(x)) == x assert erfc(erfinv(x)) == 1 - x assert erfc(I).is_extended_real is False assert erfc(w).is_extended_real is True assert erfc(z).is_extended_real is None assert conjugate(erfc(z)) == erfc(conjugate(z)) assert erfc(x).as_leading_term(x) == 1 assert erfc(1 / x).as_leading_term(x) == erfc(1 / x) assert erfc(z).rewrite('erf') == 1 - erf(z) assert erfc(z).rewrite('erfi') == 1 + I * erfi(I * z) assert erfc(z).rewrite('fresnels') == 1 - (1 + I) * ( fresnelc(z * (1 - I) / sqrt(pi)) - I * fresnels(z * (1 - I) / sqrt(pi))) assert erfc(z).rewrite('fresnelc') == 1 - (1 + I) * ( fresnelc(z * (1 - I) / sqrt(pi)) - I * fresnels(z * (1 - I) / sqrt(pi))) assert erfc(z).rewrite('hyper') == 1 - 2 * z * hyper( [Rational(1, 2)], [Rational(3, 2)], -z**2) / sqrt(pi) assert erfc(z).rewrite('meijerg') == 1 - z * meijerg( [Rational(1, 2)], [], [0], [Rational(-1, 2)], z**2) / sqrt(pi) assert erfc(z).rewrite( 'uppergamma') == 1 - sqrt(z**2) * erf(sqrt(z**2)) / z assert erfc(z).rewrite('expint') == 1 - sqrt(z**2) / z + z * expint( Rational(1, 2), z**2) / sqrt(pi) assert erfc(x).as_real_imag() == \ ((erfc(re(x) - I*re(x)*abs(im(x))/abs(re(x)))/2 + erfc(re(x) + I*re(x)*abs(im(x))/abs(re(x)))/2, I*(erfc(re(x) - I*re(x)*abs(im(x))/abs(re(x))) - erfc(re(x) + I*re(x)*abs(im(x))/abs(re(x)))) * re(x)*abs(im(x))/(2*im(x)*abs(re(x))))) assert erfc(x).as_real_imag(deep=False) == erfc(x).as_real_imag() assert erfc(w).as_real_imag() == (erfc(w), 0) assert erfc(w).as_real_imag(deep=False) == erfc(w).as_real_imag() assert erfc(I).as_real_imag() == (1, -erfi(1)) pytest.raises(ArgumentIndexError, lambda: erfc(x).fdiff(2)) assert erfc(x).taylor_term(3, x, *(-2 * x / sqrt(pi), 0)) == 2 * x**3 / 3 / sqrt(pi) assert erfc(x).limit(x, oo) == 0 assert erfc(x).diff(x) == -2 * exp(-x**2) / sqrt(pi)
def test_meijerg_with_Floats(): # see sympy/sympy#10681 f = meijerg(((3.0, 1), ()), ((Rational(3, 2),), (0,)), z) a = -2.3632718012073 g = a*z**Rational(3, 2)*hyper((-0.5, Rational(3, 2)), (Rational(5, 2),), z*exp_polar(I*pi)) assert RR.almosteq((hyperexpand(f)/g).n(), 1.0, 1e-12)
def test_meijerg_expand(): from diofant import combsimp, simplify # from mpmath docs assert hyperexpand(meijerg([[], []], [[0], []], -z)) == exp(z) assert hyperexpand(meijerg([[1, 1], []], [[1], [0]], z)) == \ log(z + 1) assert hyperexpand(meijerg([[1, 1], []], [[1], [1]], z)) == \ z/(z + 1) assert hyperexpand(meijerg([[], []], [[Rational(1, 2)], [0]], (z/2)**2)) \ == sin(z)/sqrt(pi) assert hyperexpand(meijerg([[], []], [[0], [Rational(1, 2)]], (z/2)**2)) \ == cos(z)/sqrt(pi) assert can_do_meijer([], [a], [a - 1, a - S.Half], []) assert can_do_meijer([], [], [a / 2], [-a / 2], False) # branches... assert can_do_meijer([a], [b], [a], [b, a - 1]) # wikipedia assert hyperexpand(meijerg([1], [], [], [0], z)) == \ Piecewise((0, abs(z) < 1), (1, abs(1/z) < 1), (meijerg([1], [], [], [0], z), True)) assert hyperexpand(meijerg([], [1], [0], [], z)) == \ Piecewise((1, abs(z) < 1), (0, abs(1/z) < 1), (meijerg([], [1], [0], [], z), True)) # The Special Functions and their Approximations assert can_do_meijer([], [], [a + b / 2], [a, a - b / 2, a + S.Half]) assert can_do_meijer([], [], [a], [b], False) # branches only agree for small z assert can_do_meijer([], [S.Half], [a], [-a]) assert can_do_meijer([], [], [a, b], []) assert can_do_meijer([], [], [a, b], []) assert can_do_meijer([], [], [a, a + S.Half], [b, b + S.Half]) assert can_do_meijer([], [], [a, -a], [0, S.Half], False) # dito assert can_do_meijer([], [], [a, a + S.Half, b, b + S.Half], []) assert can_do_meijer([S.Half], [], [0], [a, -a]) assert can_do_meijer([S.Half], [], [a], [0, -a], False) # dito assert can_do_meijer([], [a - S.Half], [a, b], [a - S.Half], False) assert can_do_meijer([], [a + S.Half], [a + b, a - b, a], [], False) assert can_do_meijer([a + S.Half], [], [b, 2 * a - b, a], [], False) # This for example is actually zero. assert can_do_meijer([], [], [], [a, b]) # Testing a bug: assert hyperexpand(meijerg([0, 2], [], [], [-1, 1], z)) == \ Piecewise((0, abs(z) < 1), (z/2 - 1/(2*z), abs(1/z) < 1), (meijerg([0, 2], [], [], [-1, 1], z), True)) # Test that the simplest possible answer is returned: assert combsimp(simplify(hyperexpand( meijerg([1], [1 - a], [-a/2, -a/2 + Rational(1, 2)], [], 1/z)))) == \ -2*sqrt(pi)*(sqrt(z + 1) + 1)**a/a # Test that hyper is returned assert hyperexpand(meijerg([1], [], [a], [0, 0], z)) == hyper( (a, ), (a + 1, a + 1), z * exp_polar(I * pi)) * z**a * gamma(a) / gamma(a + 1)**2
def can_do(ap, bq, numerical=True, div=1, lowerplane=False): from diofant import exp_polar, exp r = hyperexpand(hyper(ap, bq, z)) if r.has(hyper): return False if not numerical: return True repl = {} for n, a in enumerate(r.free_symbols - {z}): repl[a] = randcplx(n)/div [a, b, c, d] = [2, -1, 3, 1] if lowerplane: [a, b, c, d] = [2, -2, 3, -1] return tn( hyper(ap, bq, z).subs(repl), r.replace(exp_polar, exp).subs(repl), z, a=a, b=b, c=c, d=d)
def test_erfi(): assert erfi(nan) == nan assert erfi(+oo) == +oo assert erfi(-oo) == -oo assert erfi(0) == 0 assert erfi(I * oo) == I assert erfi(-I * oo) == -I assert erfi(-x) == -erfi(x) assert erfi(I * erfinv(x)) == I * x assert erfi(I * erfcinv(x)) == I * (1 - x) assert erfi(I * erf2inv(0, x)) == I * x assert erfi(I).is_extended_real is False assert erfi(w).is_extended_real is True assert erfi(z).is_extended_real is None assert conjugate(erfi(z)) == erfi(conjugate(z)) assert erfi(z).rewrite('erf') == -I * erf(I * z) assert erfi(z).rewrite('erfc') == I * erfc(I * z) - I assert erfi(z).rewrite('fresnels') == (1 - I) * ( fresnelc(z * (1 + I) / sqrt(pi)) - I * fresnels(z * (1 + I) / sqrt(pi))) assert erfi(z).rewrite('fresnelc') == (1 - I) * ( fresnelc(z * (1 + I) / sqrt(pi)) - I * fresnels(z * (1 + I) / sqrt(pi))) assert erfi(z).rewrite('hyper') == 2 * z * hyper( [Rational(1, 2)], [Rational(3, 2)], z**2) / sqrt(pi) assert erfi(z).rewrite('meijerg') == z * meijerg( [Rational(1, 2)], [], [0], [Rational(-1, 2)], -z**2) / sqrt(pi) assert erfi(z).rewrite('uppergamma') == ( sqrt(-z**2) / z * (uppergamma(Rational(1, 2), -z**2) / sqrt(pi) - 1)) assert erfi(z).rewrite('expint') == sqrt(-z**2) / z - z * expint( Rational(1, 2), -z**2) / sqrt(pi) assert erfi(x).as_real_imag() == \ ((erfi(re(x) - I*re(x)*abs(im(x))/abs(re(x)))/2 + erfi(re(x) + I*re(x)*abs(im(x))/abs(re(x)))/2, I*(erfi(re(x) - I*re(x)*abs(im(x))/abs(re(x))) - erfi(re(x) + I*re(x)*abs(im(x))/abs(re(x)))) * re(x)*abs(im(x))/(2*im(x)*abs(re(x))))) assert erfi(x).as_real_imag(deep=False) == erfi(x).as_real_imag() assert erfi(w).as_real_imag() == (erfi(w), 0) assert erfi(w).as_real_imag(deep=False) == erfi(w).as_real_imag() assert erfi(I).as_real_imag() == (0, erf(1)) pytest.raises(ArgumentIndexError, lambda: erfi(x).fdiff(2)) assert erfi(x).taylor_term(3, x, *(2 * x / sqrt(pi), 0)) == 2 * x**3 / 3 / sqrt(pi) assert erfi(x).limit(x, oo) == oo
def test_airyai(): z = Symbol('z', extended_real=False) t = Symbol('t', negative=True) p = Symbol('p', positive=True) assert isinstance(airyai(z), airyai) assert airyai(0) == 3**Rational(1, 3) / (3 * gamma(Rational(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**Rational(5, 6) * gamma(Rational(1, 3)) / (6 * pi) - 3**Rational(1, 6) * z * gamma(Rational(2, 3)) / (2 * pi) + O(z**3)) assert airyai(z).rewrite(hyper) == (-3**Rational(2, 3) * z * hyper( (), (Rational(4, 3), ), z**Integer(3) / 9) / (3 * gamma(Rational(1, 3))) + 3**Rational(1, 3) * hyper( (), (Rational(2, 3), ), z**Integer(3) / 9) / (3 * gamma(Rational(2, 3)))) assert isinstance(airyai(z).rewrite(besselj), airyai) assert airyai(t).rewrite(besselj) == ( sqrt(-t) * (besselj(-Rational(1, 3), 2 * (-t)**Rational(3, 2) / 3) + besselj(Rational(1, 3), 2 * (-t)**Rational(3, 2) / 3)) / 3) assert airyai(z).rewrite(besseli) == ( -z * besseli(Rational(1, 3), 2 * z**Rational(3, 2) / 3) / (3 * (z**Rational(3, 2))**Rational(1, 3)) + (z**Rational(3, 2))**Rational(1, 3) * besseli(-Rational(1, 3), 2 * z**Rational(3, 2) / 3) / 3) assert airyai(p).rewrite(besseli) == ( sqrt(p) * (besseli(-Rational(1, 3), 2 * p**Rational(3, 2) / 3) - besseli(Rational(1, 3), 2 * p**Rational(3, 2) / 3)) / 3) assert expand_func(airyai(2 * (3 * z**5)**Rational(1, 3))) == ( -sqrt(3) * (-1 + (z**5)**Rational(1, 3) / z**Rational(5, 3)) * airybi(2 * 3**Rational(1, 3) * z**Rational(5, 3)) / 6 + (1 + (z**5)**Rational(1, 3) / z**Rational(5, 3)) * airyai(2 * 3**Rational(1, 3) * z**Rational(5, 3)) / 2)
def test_jacobi(): assert jacobi(0, a, b, x) == 1 assert jacobi(1, a, b, x) == a/2 - b/2 + x*(a/2 + b/2 + 1) assert (jacobi(2, a, b, x) == a**2/8 - a*b/4 - a/8 + b**2/8 - b/8 + x**2*(a**2/8 + a*b/4 + 7*a/8 + b**2/8 + 7*b/8 + Rational(3, 2)) + x*(a**2/4 + 3*a/4 - b**2/4 - 3*b/4) - Rational(1, 2)) assert jacobi(n, a, a, x) == RisingFactorial( a + 1, n)*gegenbauer(n, a + Rational(1, 2), x)/RisingFactorial(2*a + 1, n) assert jacobi(n, a, -a, x) == ((-1)**a*(-x + 1)**(-a/2)*(x + 1)**(a/2)*assoc_legendre(n, a, x) * factorial(-a + n)*gamma(a + n + 1)/(factorial(a + n)*gamma(n + 1))) assert jacobi(n, -b, b, x) == ((-x + 1)**(b/2)*(x + 1)**(-b/2)*assoc_legendre(n, b, x) * gamma(-b + n + 1)/gamma(n + 1)) assert jacobi(n, 0, 0, x) == legendre(n, x) assert jacobi(n, Rational(1, 2), Rational(1, 2), x) == RisingFactorial( Rational(3, 2), n)*chebyshevu(n, x)/factorial(n + 1) assert jacobi(n, Rational(-1, 2), Rational(-1, 2), x) == RisingFactorial( Rational(1, 2), n)*chebyshevt(n, x)/factorial(n) X = jacobi(n, a, b, x) assert isinstance(X, jacobi) assert jacobi(n, a, b, -x) == (-1)**n*jacobi(n, b, a, x) assert jacobi(n, a, b, 0) == 2**(-n)*gamma(a + n + 1)*hyper( (-b - n, -n), (a + 1,), -1)/(factorial(n)*gamma(a + 1)) assert jacobi(n, a, b, 1) == RisingFactorial(a + 1, n)/factorial(n) m = Symbol("m", positive=True) assert jacobi(m, a, b, oo) == oo*RisingFactorial(a + b + m + 1, m) assert jacobi(n, a, b, oo) == jacobi(n, a, b, oo, evaluate=False) assert conjugate(jacobi(m, a, b, x)) == \ jacobi(m, conjugate(a), conjugate(b), conjugate(x)) assert diff(jacobi(n, a, b, x), n) == Derivative(jacobi(n, a, b, x), n) assert diff(jacobi(n, a, b, x), x) == \ (a/2 + b/2 + n/2 + Rational(1, 2))*jacobi(n - 1, a + 1, b + 1, x) # XXX see issue sympy/sympy#5539 assert str(jacobi(n, a, b, x).diff(a)) == \ ("Sum((jacobi(n, a, b, x) + (a + b + 2*_k + 1)*RisingFactorial(b + " "_k + 1, n - _k)*jacobi(_k, a, b, x)/((n - _k)*RisingFactorial(a + " "b + _k + 1, n - _k)))/(a + b + n + _k + 1), (_k, 0, n - 1))") assert str(jacobi(n, a, b, x).diff(b)) == \ ("Sum(((-1)**(n - _k)*(a + b + 2*_k + 1)*RisingFactorial(a + " "_k + 1, n - _k)*jacobi(_k, a, b, x)/((n - _k)*RisingFactorial(a + " "b + _k + 1, n - _k)) + jacobi(n, a, b, x))/(a + b + n + " "_k + 1), (_k, 0, n - 1))") assert jacobi_normalized(n, a, b, x) == \ (jacobi(n, a, b, x)/sqrt(2**(a + b + 1)*gamma(a + n + 1)*gamma(b + n + 1) / ((a + b + 2*n + 1)*factorial(n)*gamma(a + b + n + 1)))) pytest.raises(ValueError, lambda: jacobi(-2.1, a, b, x)) pytest.raises(ValueError, lambda: jacobi(Dummy(positive=True, integer=True), 1, 2, oo)) pytest.raises(ArgumentIndexError, lambda: jacobi(n, a, b, x).fdiff(5))
def test_airybi(): z = Symbol('z', extended_real=False) t = Symbol('t', negative=True) p = Symbol('p', positive=True) assert isinstance(airybi(z), airybi) assert airybi(0) == 3**Rational(5, 6)/(3*gamma(Rational(2, 3))) assert airybi(oo) == oo assert airybi(-oo) == 0 assert diff(airybi(z), z) == airybiprime(z) assert series(airybi(z), z, 0, 3) == ( cbrt(3)*gamma(Rational(1, 3))/(2*pi) + 3**Rational(2, 3)*z*gamma(Rational(2, 3))/(2*pi) + O(z**3)) l = Limit(airybi(I/x)/(exp(Rational(2, 3)*(I/x)**Rational(3, 2))*sqrt(pi*sqrt(I/x))), x, 0) assert l.doit() == l assert airybi(z).rewrite(hyper) == ( root(3, 6)*z*hyper((), (Rational(4, 3),), z**3/9)/gamma(Rational(1, 3)) + 3**Rational(5, 6)*hyper((), (Rational(2, 3),), z**3/9)/(3*gamma(Rational(2, 3)))) assert isinstance(airybi(z).rewrite(besselj), airybi) assert (airybi(t).rewrite(besselj) == sqrt(3)*sqrt(-t)*(besselj(-1/3, 2*(-t)**Rational(3, 2)/3) - besselj(Rational(1, 3), 2*(-t)**Rational(3, 2)/3))/3) assert airybi(z).rewrite(besseli) == ( sqrt(3)*(z*besseli(Rational(1, 3), 2*z**Rational(3, 2)/3)/cbrt(z**Rational(3, 2)) + cbrt(z**Rational(3, 2))*besseli(-Rational(1, 3), 2*z**Rational(3, 2)/3))/3) assert airybi(p).rewrite(besseli) == ( sqrt(3)*sqrt(p)*(besseli(-Rational(1, 3), 2*p**Rational(3, 2)/3) + besseli(Rational(1, 3), 2*p**Rational(3, 2)/3))/3) assert airybi(p).rewrite(besselj) == airybi(p) assert expand_func(airybi(2*cbrt(3*z**5))) == ( sqrt(3)*(1 - cbrt(z**5)/z**Rational(5, 3))*airyai(2*cbrt(3)*z**Rational(5, 3))/2 + (1 + cbrt(z**5)/z**Rational(5, 3))*airybi(2*cbrt(3)*z**Rational(5, 3))/2) assert expand_func(airybi(x*y)) == airybi(x*y) assert expand_func(airybi(log(x))) == airybi(log(x)) assert expand_func(airybi(2*root(3*z**5, 5))) == airybi(2*root(3*z**5, 5)) assert airybi(x).taylor_term(-1, x) == 0
def test_E(): assert E(z, 0) == z assert E(0, m) == 0 assert E(i*pi/2, m) == i*E(m) assert E(z, oo) == zoo assert E(z, -oo) == zoo assert E(0) == pi/2 assert E(1) == 1 assert E(oo) == I*oo assert E(-oo) == oo assert E(zoo) == zoo assert E(-z, m) == -E(z, m) assert E(z, m).diff(z) == sqrt(1 - m*sin(z)**2) assert E(z, m).diff(m) == (E(z, m) - F(z, m))/(2*m) assert E(z).diff(z) == (E(z) - K(z))/(2*z) r = randcplx() assert td(E(r, m), m) assert td(E(z, r), z) assert td(E(z), z) pytest.raises(ArgumentIndexError, lambda: E(z, m).fdiff(3)) pytest.raises(ArgumentIndexError, lambda: E(z).fdiff(2)) mi = Symbol('m', extended_real=False) assert E(z, mi).conjugate() == E(z.conjugate(), mi.conjugate()) assert E(mi).conjugate() == E(mi.conjugate()) mr = Symbol('m', extended_real=True, negative=True) assert E(z, mr).conjugate() == E(z.conjugate(), mr) assert E(mr).conjugate() == E(mr) assert E(z).rewrite(hyper) == (pi/2)*hyper((-S.Half, S.Half), (S.One,), z) assert E(z, m).rewrite(hyper) == E(z, m) assert tn(E(z), (pi/2)*hyper((-S.Half, S.Half), (S.One,), z)) assert E(z).rewrite(meijerg) == \ -meijerg(((S.Half, Rational(3, 2)), []), ((S.Zero,), (S.Zero,)), -z)/4 assert E(z, m).rewrite(meijerg) == E(z, m) assert tn(E(z), -meijerg(((S.Half, Rational(3, 2)), []), ((S.Zero,), (S.Zero,)), -z)/4) assert E(z, m).series(z) == \ z + z**5*(-m**2/40 + m/30) - m*z**3/6 + O(z**6) assert E(z).series(z) == pi/2 - pi*z/8 - 3*pi*z**2/128 - \ 5*pi*z**3/512 - 175*pi*z**4/32768 - 441*pi*z**5/131072 + O(z**6)
def test_lerchphi(): from diofant import combsimp, exp_polar, polylog, log, lerchphi assert hyperexpand(hyper([1, a], [a + 1], z) / a) == lerchphi(z, 1, a) assert hyperexpand(hyper([1, a, a], [a + 1, a + 1], z) / a**2) == lerchphi( z, 2, a) assert hyperexpand(hyper([1, a, a, a], [a + 1, a + 1, a + 1], z)/a**3) == \ lerchphi(z, 3, a) assert hyperexpand(hyper([1] + [a]*10, [a + 1]*10, z)/a**10) == \ lerchphi(z, 10, a) assert combsimp( hyperexpand(meijerg([0, 1 - a], [], [0], [-a], exp_polar(-I * pi) * z))) == lerchphi(z, 1, a) assert combsimp( hyperexpand( meijerg([0, 1 - a, 1 - a], [], [0], [-a, -a], exp_polar(-I * pi) * z))) == lerchphi(z, 2, a) assert combsimp( hyperexpand( meijerg([0, 1 - a, 1 - a, 1 - a], [], [0], [-a, -a, -a], exp_polar(-I * pi) * z))) == lerchphi(z, 3, a) assert hyperexpand(z * hyper([1, 1], [2], z)) == -log(1 + -z) assert hyperexpand(z * hyper([1, 1, 1], [2, 2], z)) == polylog(2, z) assert hyperexpand(z * hyper([1, 1, 1, 1], [2, 2, 2], z)) == polylog(3, z) assert hyperexpand(hyper([1, a, 1 + Rational(1, 2)], [a + 1, Rational(1, 2)], z)) == \ -2*a/(z - 1) + (-2*a**2 + a)*lerchphi(z, 1, a) # Now numerical tests. These make sure reductions etc are carried out # correctly # a rational function (polylog at negative integer order) assert can_do([2, 2, 2], [1, 1]) # NOTE these contain log(1-x) etc ... better make sure we have |z| < 1 # reduction of order for polylog assert can_do([1, 1, 1, b + 5], [2, 2, b], div=10) # reduction of order for lerchphi # XXX lerchphi in mpmath is flaky assert can_do([1, a, a, a, b + 5], [a + 1, a + 1, a + 1, b], numerical=False) # test a bug from diofant import Abs assert hyperexpand(hyper([Rational(1, 2), Rational(1, 2), Rational(1, 2), 1], [Rational(3, 2), Rational(3, 2), Rational(3, 2)], Rational(1, 4))) == \ Abs(-polylog(3, exp_polar(I*pi)/2) + polylog(3, Rational(1, 2)))
def test_erfc(): assert erfc(nan) == nan assert erfc(oo) == 0 assert erfc(-oo) == 2 assert erfc(0) == 1 assert erfc(I*oo) == -oo*I assert erfc(-I*oo) == oo*I assert erfc(-x) == Integer(2) - erfc(x) assert erfc(erfcinv(x)) == x assert erfc(erfinv(x)) == 1 - x assert erfc(I).is_extended_real is False assert erfc(w).is_extended_real is True assert erfc(z).is_extended_real is None assert conjugate(erfc(z)) == erfc(conjugate(z)) assert erfc(x).as_leading_term(x) == 1 assert erfc(1/x).as_leading_term(x) == erfc(1/x) assert erfc(z).rewrite('erf') == 1 - erf(z) assert erfc(z).rewrite('erfi') == 1 + I*erfi(I*z) assert erfc(z).rewrite('fresnels') == 1 - (1 + I)*(fresnelc(z*(1 - I)/sqrt(pi)) - I*fresnels(z*(1 - I)/sqrt(pi))) assert erfc(z).rewrite('fresnelc') == 1 - (1 + I)*(fresnelc(z*(1 - I)/sqrt(pi)) - I*fresnels(z*(1 - I)/sqrt(pi))) assert erfc(z).rewrite('hyper') == 1 - 2*z*hyper([Rational(1, 2)], [Rational(3, 2)], -z**2)/sqrt(pi) assert erfc(z).rewrite('meijerg') == 1 - z*meijerg([Rational(1, 2)], [], [0], [Rational(-1, 2)], z**2)/sqrt(pi) assert erfc(z).rewrite('uppergamma') == 1 - sqrt(z**2)*erf(sqrt(z**2))/z assert erfc(z).rewrite('expint') == 1 - sqrt(z**2)/z + z*expint(Rational(1, 2), z**2)/sqrt(pi) assert erfc(x).as_real_imag() == \ ((erfc(re(x) - I*re(x)*Abs(im(x))/Abs(re(x)))/2 + erfc(re(x) + I*re(x)*Abs(im(x))/Abs(re(x)))/2, I*(erfc(re(x) - I*re(x)*Abs(im(x))/Abs(re(x))) - erfc(re(x) + I*re(x)*Abs(im(x))/Abs(re(x)))) * re(x)*Abs(im(x))/(2*im(x)*Abs(re(x))))) assert erfc(x).as_real_imag(deep=False) == erfc(x).as_real_imag() assert erfc(w).as_real_imag() == (erfc(w), 0) assert erfc(w).as_real_imag(deep=False) == erfc(w).as_real_imag() assert erfc(I).as_real_imag() == (1, -erfi(1)) pytest.raises(ArgumentIndexError, lambda: erfc(x).fdiff(2)) assert erfc(x).taylor_term(3, x, *(-2*x/sqrt(pi), 0)) == 2*x**3/3/sqrt(pi) assert erfc(x).limit(x, oo) == 0 assert erfc(x).diff(x) == -2*exp(-x**2)/sqrt(pi)
def can_do(ap, bq, numerical=True, div=1, lowerplane=False): r = hyperexpand(hyper(ap, bq, z)) if r.has(hyper): return False if not numerical: return True repl = {} randsyms = r.free_symbols - {z} while randsyms: # Only randomly generated parameters are checked. for n, a in enumerate(randsyms): repl[a] = randcplx(n)/div if not any(b.is_Integer and b <= 0 for b in Tuple(*bq).subs(repl)): break [a, b, c, d] = [2, -1, 3, 1] if lowerplane: [a, b, c, d] = [2, -2, 3, -1] return tn( hyper(ap, bq, z).subs(repl), r.replace(exp_polar, exp).subs(repl), z, a=a, b=b, c=c, d=d)
def test_airybiprime(): z = Symbol('z', extended_real=False) t = Symbol('t', negative=True) p = Symbol('p', positive=True) assert isinstance(airybiprime(z), airybiprime) assert airybiprime(0) == root(3, 6)/gamma(Rational(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) == ( root(3, 6)/gamma(Rational(1, 3)) + 3**Rational(5, 6)*z**2/(6*gamma(Rational(2, 3))) + O(z**3)) assert airybiprime(z).rewrite(hyper) == ( 3**Rational(5, 6)*z**2*hyper((), (Rational(5, 3),), z**3/9)/(6*gamma(Rational(2, 3))) + root(3, 6)*hyper((), (Rational(1, 3),), z**3/9)/gamma(Rational(1, 3))) assert isinstance(airybiprime(z).rewrite(besselj), airybiprime) assert (airybiprime(t).rewrite(besselj) == -sqrt(3)*t*(besselj(-Rational(2, 3), 2*(-t)**Rational(3, 2)/3) + besselj(Rational(2, 3), 2*(-t)**Rational(3, 2)/3))/3) assert airybiprime(z).rewrite(besseli) == ( sqrt(3)*(z**2*besseli(Rational(2, 3), 2*z**Rational(3, 2)/3)/(z**Rational(3, 2))**Rational(2, 3) + (z**Rational(3, 2))**Rational(2, 3)*besseli(-Rational(2, 3), 2*z**Rational(3, 2)/3))/3) assert airybiprime(p).rewrite(besseli) == ( sqrt(3)*p*(besseli(-Rational(2, 3), 2*p**Rational(3, 2)/3) + besseli(Rational(2, 3), 2*p**Rational(3, 2)/3))/3) assert airybiprime(p).rewrite(besselj) == airybiprime(p) assert expand_func(airybiprime(2*cbrt(3*z**5))) == ( sqrt(3)*(z**Rational(5, 3)/cbrt(z**5) - 1)*airyaiprime(2*cbrt(3)*z**Rational(5, 3))/2 + (z**Rational(5, 3)/cbrt(z**5) + 1)*airybiprime(2*cbrt(3)*z**Rational(5, 3))/2) assert expand_func(airybiprime(x*y)) == airybiprime(x*y) assert expand_func(airybiprime(log(x))) == airybiprime(log(x)) assert expand_func(airybiprime(2*root(3*z**5, 5))) == airybiprime(2*root(3*z**5, 5)) assert airybiprime(-2).evalf(50) == Float('0.27879516692116952268509756941098324140300059345163131', dps=50)
def test_erfi(): assert erfi(nan) == nan assert erfi(+oo) == +oo assert erfi(-oo) == -oo assert erfi(0) == 0 assert erfi(I*oo) == I assert erfi(-I*oo) == -I assert erfi(-x) == -erfi(x) assert erfi(I*erfinv(x)) == I*x assert erfi(I*erfcinv(x)) == I*(1 - x) assert erfi(I*erf2inv(0, x)) == I*x assert erfi(I).is_extended_real is False assert erfi(w).is_extended_real is True assert erfi(z).is_extended_real is None assert conjugate(erfi(z)) == erfi(conjugate(z)) assert erfi(z).rewrite('erf') == -I*erf(I*z) assert erfi(z).rewrite('erfc') == I*erfc(I*z) - I assert erfi(z).rewrite('fresnels') == (1 - I)*(fresnelc(z*(1 + I)/sqrt(pi)) - I*fresnels(z*(1 + I)/sqrt(pi))) assert erfi(z).rewrite('fresnelc') == (1 - I)*(fresnelc(z*(1 + I)/sqrt(pi)) - I*fresnels(z*(1 + I)/sqrt(pi))) assert erfi(z).rewrite('hyper') == 2*z*hyper([Rational(1, 2)], [Rational(3, 2)], z**2)/sqrt(pi) assert erfi(z).rewrite('meijerg') == z*meijerg([Rational(1, 2)], [], [0], [Rational(-1, 2)], -z**2)/sqrt(pi) assert erfi(z).rewrite('uppergamma') == (sqrt(-z**2)/z*(uppergamma(Rational(1, 2), -z**2)/sqrt(pi) - 1)) assert erfi(z).rewrite('expint') == sqrt(-z**2)/z - z*expint(Rational(1, 2), -z**2)/sqrt(pi) assert erfi(x).as_real_imag() == \ ((erfi(re(x) - I*re(x)*Abs(im(x))/Abs(re(x)))/2 + erfi(re(x) + I*re(x)*Abs(im(x))/Abs(re(x)))/2, I*(erfi(re(x) - I*re(x)*Abs(im(x))/Abs(re(x))) - erfi(re(x) + I*re(x)*Abs(im(x))/Abs(re(x)))) * re(x)*Abs(im(x))/(2*im(x)*Abs(re(x))))) assert erfi(x).as_real_imag(deep=False) == erfi(x).as_real_imag() assert erfi(w).as_real_imag() == (erfi(w), 0) assert erfi(w).as_real_imag(deep=False) == erfi(w).as_real_imag() assert erfi(I).as_real_imag() == (0, erf(1)) pytest.raises(ArgumentIndexError, lambda: erfi(x).fdiff(2)) assert erfi(x).taylor_term(3, x, *(2*x/sqrt(pi), 0)) == 2*x**3/3/sqrt(pi) assert erfi(x).limit(x, oo) == oo
def test_airyaiprime(): z = Symbol('z', extended_real=False) t = Symbol('t', negative=True) p = Symbol('p', positive=True) assert isinstance(airyaiprime(z), airyaiprime) assert airyaiprime(0) == -3**Rational(2, 3)/(3*gamma(Rational(1, 3))) assert airyaiprime(oo) == 0 assert diff(airyaiprime(z), z) == z*airyai(z) assert series(airyaiprime(z), z, 0, 3) == ( -3**Rational(2, 3)/(3*gamma(Rational(1, 3))) + cbrt(3)*z**2/(6*gamma(Rational(2, 3))) + O(z**3)) assert airyaiprime(z).rewrite(hyper) == ( cbrt(3)*z**2*hyper((), (Rational(5, 3),), z**3/9)/(6*gamma(Rational(2, 3))) - 3**Rational(2, 3)*hyper((), (Rational(1, 3),), z**3/9)/(3*gamma(Rational(1, 3)))) assert isinstance(airyaiprime(z).rewrite(besselj), airyaiprime) assert (airyaiprime(t).rewrite(besselj) == t*(besselj(-Rational(2, 3), 2*(-t)**Rational(3, 2)/3) - besselj(Rational(2, 3), 2*(-t)**Rational(3, 2)/3))/3) assert airyaiprime(z).rewrite(besseli) == ( z**2*besseli(Rational(2, 3), 2*z**Rational(3, 2)/3)/(3*(z**Rational(3, 2))**Rational(2, 3)) - (z**Rational(3, 2))**Rational(2, 3)*besseli(-Rational(1, 3), 2*z**Rational(3, 2)/3)/3) assert airyaiprime(p).rewrite(besseli) == ( p*(-besseli(-Rational(2, 3), 2*p**Rational(3, 2)/3) + besseli(Rational(2, 3), 2*p**Rational(3, 2)/3))/3) assert airyaiprime(p).rewrite(besselj) == airyaiprime(p) assert expand_func(airyaiprime(2*cbrt(3*z**5))) == ( sqrt(3)*(z**Rational(5, 3)/cbrt(z**5) - 1)*airybiprime(2*cbrt(3)*z**Rational(5, 3))/6 + (z**Rational(5, 3)/cbrt(z**5) + 1)*airyaiprime(2*cbrt(3)*z**Rational(5, 3))/2) assert expand_func(airyaiprime(x*y)) == airyaiprime(x*y) assert expand_func(airyaiprime(log(x))) == airyaiprime(log(x)) assert expand_func(airyaiprime(2*root(3*z**5, 5))) == airyaiprime(2*root(3*z**5, 5)) assert airyaiprime(-2).evalf(50) == Float('0.61825902074169104140626429133247528291577794512414753', dps=50)
def test_lerchphi(): assert hyperexpand(hyper([1, a], [a + 1], z)/a) == lerchphi(z, 1, a) assert hyperexpand( hyper([1, a, a], [a + 1, a + 1], z)/a**2) == lerchphi(z, 2, a) assert hyperexpand(hyper([1, a, a, a], [a + 1, a + 1, a + 1], z)/a**3) == \ lerchphi(z, 3, a) assert hyperexpand(hyper([1] + [a]*10, [a + 1]*10, z)/a**10) == \ lerchphi(z, 10, a) assert combsimp(hyperexpand(meijerg([0, 1 - a], [], [0], [-a], exp_polar(-I*pi)*z))) == lerchphi(z, 1, a) assert combsimp(hyperexpand(meijerg([0, 1 - a, 1 - a], [], [0], [-a, -a], exp_polar(-I*pi)*z))) == lerchphi(z, 2, a) assert combsimp(hyperexpand(meijerg([0, 1 - a, 1 - a, 1 - a], [], [0], [-a, -a, -a], exp_polar(-I*pi)*z))) == lerchphi(z, 3, a) assert hyperexpand(z*hyper([1, 1], [2], z)) == -log(1 + -z) assert hyperexpand(z*hyper([1, 1, 1], [2, 2], z)) == polylog(2, z) assert hyperexpand(z*hyper([1, 1, 1, 1], [2, 2, 2], z)) == polylog(3, z) assert hyperexpand(hyper([1, a, 1 + Rational(1, 2)], [a + 1, Rational(1, 2)], z)) == \ -2*a/(z - 1) + (-2*a**2 + a)*lerchphi(z, 1, a) # Now numerical tests. These make sure reductions etc are carried out # correctly # a rational function (polylog at negative integer order) assert can_do([2, 2, 2], [1, 1]) # NOTE these contain log(1-x) etc ... better make sure we have |z| < 1 # reduction of order for polylog assert can_do([1, 1, 1, b + 5], [2, 2, b], div=10) # reduction of order for lerchphi # XXX lerchphi in mpmath is flaky assert can_do( [1, a, a, a, b + 5], [a + 1, a + 1, a + 1, b], numerical=False) # test a bug assert hyperexpand(hyper([Rational(1, 2), Rational(1, 2), Rational(1, 2), 1], [Rational(3, 2), Rational(3, 2), Rational(3, 2)], Rational(1, 4))) == \ abs(-polylog(3, exp_polar(I*pi)/2) + polylog(3, Rational(1, 2)))
def test_reduction_operators(): a1, a2, b1 = (randcplx(n) for n in range(3)) h = hyper([a1], [b1], z) assert ReduceOrder(2, 0) is None assert ReduceOrder(2, -1) is None assert ReduceOrder(1, Rational(1, 2)) is None h2 = hyper((a1, a2), (b1, a2), z) assert tn(ReduceOrder(a2, a2).apply(h, op), h2, z) h2 = hyper((a1, a2 + 1), (b1, a2), z) assert tn(ReduceOrder(a2 + 1, a2).apply(h, op), h2, z) h2 = hyper((a2 + 4, a1), (b1, a2), z) assert tn(ReduceOrder(a2 + 4, a2).apply(h, op), h2, z) # test several step order reduction ap = (a2 + 4, a1, b1 + 1) bq = (a2, b1, b1) func, ops = reduce_order(Hyper_Function(ap, bq)) assert func.ap == (a1,) assert func.bq == (b1,) assert tn(apply_operators(h, ops, op), hyper(ap, bq, z), z)
def test_shift_operators(): a1, a2, b1, b2, b3 = (randcplx(n) for n in range(5)) h = hyper((a1, a2), (b1, b2, b3), z) pytest.raises(ValueError, lambda: ShiftA(0)) pytest.raises(ValueError, lambda: ShiftB(1)) assert tn(ShiftA(a1).apply(h, op), hyper((a1 + 1, a2), (b1, b2, b3), z), z) assert tn(ShiftA(a2).apply(h, op), hyper((a1, a2 + 1), (b1, b2, b3), z), z) assert tn(ShiftB(b1).apply(h, op), hyper((a1, a2), (b1 - 1, b2, b3), z), z) assert tn(ShiftB(b2).apply(h, op), hyper((a1, a2), (b1, b2 - 1, b3), z), z) assert tn(ShiftB(b3).apply(h, op), hyper((a1, a2), (b1, b2, b3 - 1), z), z)
def test_expand_func(): # evaluation at 1 of Gauss' hypergeometric function: a1, b1, c1 = randcplx(), randcplx(), randcplx() + 5 assert expand_func(hyper([a, b], [c], 1)) == \ gamma(c)*gamma(-a - b + c)/(gamma(-a + c)*gamma(-b + c)) assert abs(expand_func(hyper([a1, b1], [c1], 1)) - hyper([a1, b1], [c1], 1)).evalf(strict=False) < 1e-10 # hyperexpand wrapper for hyper: assert expand_func(hyper([], [], z)) == exp(z) assert expand_func(hyper([1, 2, 3], [], z)) == hyper([1, 2, 3], [], z) assert expand_func(meijerg([[1, 1], []], [[1], [0]], z)) == log(z + 1) assert expand_func(meijerg([[1, 1], []], [[], []], z)) == \ meijerg([[1, 1], []], [[], []], z)
def test_hyperexpand_bases(): assert hyperexpand(hyper([2], [a], z)) == \ a + z**(-a + 1)*(-a**2 + 3*a + z*(a - 1) - 2)*exp(z) * \ lowergamma(a - 1, z) - 1 # TODO [a+1, a+Rational(-1, 2)], [2*a] assert hyperexpand(hyper([1, 2], [3], z)) == -2/z - 2*log(-z + 1)/z**2 assert hyperexpand(hyper([Rational(1, 2), 2], [Rational(3, 2)], z)) == \ -1/(2*z - 2) + atanh(sqrt(z))/sqrt(z)/2 assert hyperexpand(hyper([Rational(1, 2), Rational(1, 2)], [Rational(5, 2)], z)) == \ (-3*z + 3)/4/(z*sqrt(-z + 1)) \ + (6*z - 3)*asin(sqrt(z))/(4*z**Rational(3, 2)) assert hyperexpand(hyper([1, 2], [Rational(3, 2)], z)) == -1/(2*z - 2) \ - asin(sqrt(z))/(sqrt(z)*(2*z - 2)*sqrt(-z + 1)) assert hyperexpand(hyper([Rational(-1, 2) - 1, 1, 2], [Rational(1, 2), 3], z)) == \ sqrt(z)*(6*z/7 - Rational(6, 5))*atanh(sqrt(z)) \ + (-30*z**2 + 32*z - 6)/35/z - 6*log(-z + 1)/(35*z**2) assert hyperexpand(hyper([1 + Rational(1, 2), 1, 1], [2, 2], z)) == \ -4*log(sqrt(-z + 1)/2 + Rational(1, 2))/z # TODO hyperexpand(hyper([a], [2*a + 1], z)) # TODO [Rational(1, 2), a], [Rational(3, 2), a+1] assert hyperexpand(hyper([2], [b, 1], z)) == \ z**(-b/2 + Rational(1, 2))*besseli(b - 1, 2*sqrt(z))*gamma(b) \ + z**(-b/2 + 1)*besseli(b, 2*sqrt(z))*gamma(b)
def test_li(): z = Symbol("z") zr = Symbol("z", extended_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) pytest.raises(ArgumentIndexError, lambda: li(z).fdiff(2)) 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)))
def test_ushift_operators(): a1, a2, b1, b2, b3 = (randcplx(n) for n in range(5)) h = hyper((a1, a2), (b1, b2, b3), z) pytest.raises(ValueError, lambda: UnShiftA((1,), (), 0, z)) pytest.raises(ValueError, lambda: UnShiftB((), (-1,), 0, z)) pytest.raises(ValueError, lambda: UnShiftA((1,), (0, -1, 1), 0, z)) pytest.raises(ValueError, lambda: UnShiftB((0, 1), (1,), 0, z)) s = UnShiftA((a1, a2), (b1, b2, b3), 0, z) assert tn(s.apply(h, op), hyper((a1 - 1, a2), (b1, b2, b3), z), z) s = UnShiftA((a1, a2), (b1, b2, b3), 1, z) assert tn(s.apply(h, op), hyper((a1, a2 - 1), (b1, b2, b3), z), z) s = UnShiftB((a1, a2), (b1, b2, b3), 0, z) assert tn(s.apply(h, op), hyper((a1, a2), (b1 + 1, b2, b3), z), z) s = UnShiftB((a1, a2), (b1, b2, b3), 1, z) assert tn(s.apply(h, op), hyper((a1, a2), (b1, b2 + 1, b3), z), z) s = UnShiftB((a1, a2), (b1, b2, b3), 2, z) assert tn(s.apply(h, op), hyper((a1, a2), (b1, b2, b3 + 1), z), z)
def test_hyperexpand_parametric(): assert hyperexpand(hyper([a, Rational(1, 2) + a], [Rational(1, 2)], z)) \ == (1 + sqrt(z))**(-2*a)/2 + (1 - sqrt(z))**(-2*a)/2 assert hyperexpand(hyper([a, -Rational(1, 2) + a], [2*a], z)) \ == 2**(2*a - 1)*(sqrt(-z + 1) + 1)**(-2*a + 1)
def test_sympyissue_6052(): G0 = meijerg((), (), (1,), (0,), 0) assert hyperexpand(G0) == 0 assert hyperexpand(hyper((), (2,), 0)) == 1
def test_diofantissue_203(): h = hyper((-5, -3, -4), (-6, -6), 1) assert hyperexpand(h) == Rational(1, 30) h = hyper((-6, -7, -5), (-6, -6), 1) assert hyperexpand(h) == -Rational(1, 6)
def test_diofantissue_241(): e = hyper((2, 3, 5, 9, 1), (1, 4, 6, 10), 1) assert hyperexpand(e) == Rational(108, 7)
def test_partial_simp2(): # Now test that formulae are partially simplified. c, d, e = (randcplx() for _ in range(3)) assert hyperexpand(hyper([3, a], [1, b], z)) == \ (-a*b/2 + a*z/2 + 2*a)*hyper([a + 1], [b], z) \ + (a*b/2 - 2*a + 1)*hyper([a], [b], z) assert tn( hyperexpand(hyper([3, d], [1, e], z)), hyper([3, d], [1, e], z), z) assert hyperexpand(hyper([3], [1, a, b], z)) == \ hyper((), (a, b), z) \ + z*hyper((), (a + 1, b), z)/(2*a) \ - z*(b - 4)*hyper((), (a + 1, b + 1), z)/(2*a*b) assert tn( hyperexpand(hyper([3], [1, d, e], z)), hyper([3], [1, d, e], z), z)
def test_polynomial(): assert hyperexpand(hyper([], [-1], z)) == oo assert hyperexpand(hyper([-2], [-1], z)) == oo assert hyperexpand(hyper([0, 0], [-1], z)) == 1 assert can_do([-5, -2, randcplx(), randcplx()], [-10, randcplx()]) assert hyperexpand(hyper((-1, 1), (-2,), z)) == 1 + z/2
def test_shifted_sum(): assert simplify(hyperexpand(z**4*hyper([2], [3, Rational(3, 2)], -z**2))) \ == z*sin(2*z) + (-z**2 + Rational(1, 2))*cos(2*z) - Rational(1, 2)
def test_meijerg_expand(): # from mpmath docs assert hyperexpand(meijerg([[], []], [[0], []], -z)) == exp(z) assert hyperexpand(meijerg([[1, 1], []], [[1], [0]], z)) == \ log(z + 1) assert hyperexpand(meijerg([[1, 1], []], [[1], [1]], z)) == \ z/(z + 1) assert hyperexpand(meijerg([[], []], [[Rational(1, 2)], [0]], (z/2)**2)) \ == sin(z)/sqrt(pi) assert hyperexpand(meijerg([[], []], [[0], [Rational(1, 2)]], (z/2)**2)) \ == cos(z)/sqrt(pi) assert can_do_meijer([], [a], [a - 1, a - Rational(1, 2)], []) assert can_do_meijer([], [], [a/2], [-a/2], False) # branches... assert can_do_meijer([a], [b], [a], [b, a - 1]) # wikipedia assert hyperexpand(meijerg([1], [], [], [0], z)) == \ Piecewise((0, abs(z) < 1), (1, abs(1/z) < 1), (meijerg([1], [], [], [0], z), True)) assert hyperexpand(meijerg([], [1], [0], [], z)) == \ Piecewise((1, abs(z) < 1), (0, abs(1/z) < 1), (meijerg([], [1], [0], [], z), True)) # The Special Functions and their Approximations assert can_do_meijer([], [], [a + b/2], [a, a - b/2, a + Rational(1, 2)]) assert can_do_meijer( [], [], [a], [b], False) # branches only agree for small z assert can_do_meijer([], [Rational(1, 2)], [a], [-a]) assert can_do_meijer([], [], [a, b], []) assert can_do_meijer([], [], [a, b], []) assert can_do_meijer([], [], [a, a + Rational(1, 2)], [b, b + Rational(1, 2)]) assert can_do_meijer([], [], [a, -a], [0, Rational(1, 2)], False) # dito assert can_do_meijer([], [], [a, a + Rational(1, 2), b, b + Rational(1, 2)], []) assert can_do_meijer([Rational(1, 2)], [], [0], [a, -a]) assert can_do_meijer([Rational(1, 2)], [], [a], [0, -a], False) # dito assert can_do_meijer([], [a - Rational(1, 2)], [a, b], [a - Rational(1, 2)], False) assert can_do_meijer([], [a + Rational(1, 2)], [a + b, a - b, a], [], False) assert can_do_meijer([a + Rational(1, 2)], [], [b, 2*a - b, a], [], False) # This for example is actually zero. assert can_do_meijer([], [], [], [a, b]) # Testing a bug: assert hyperexpand(meijerg([0, 2], [], [], [-1, 1], z)) == \ Piecewise((0, abs(z) < 1), (z/2 - 1/(2*z), abs(1/z) < 1), (meijerg([0, 2], [], [], [-1, 1], z), True)) # Test that the simplest possible answer is returned: assert combsimp(simplify(hyperexpand( meijerg([1], [1 - a], [-a/2, -a/2 + Rational(1, 2)], [], 1/z)))) == \ -2*sqrt(pi)*(sqrt(z + 1) + 1)**a/a # Test that hyper is returned assert hyperexpand(meijerg([1], [], [a], [0, 0], z)) == hyper( (a,), (a + 1, a + 1), z*exp_polar(I*pi))*z**a*gamma(a)/gamma(a + 1)**2 assert can_do_meijer([], [], [a + Rational(1, 2)], [a, a - b/2, a + b/2]) assert can_do_meijer([], [], [3*a - Rational(1, 2), a, -a - Rational(1, 2)], [a - Rational(1, 2)]) assert can_do_meijer([], [], [0, a - Rational(1, 2), -a - Rational(1, 2)], [Rational(1, 2)]) assert can_do_meijer([Rational(1, 2)], [], [-a, a], [0])