def test_issue_17671(): assert limit(Ei(-log(x)) - log(log(x)) / x, x, 1) == EulerGamma
def test_nth_algebraic_noprep2(): eqn = Eq(Derivative(x*Derivative(f(x), x), x)/x, exp(x)) sol = Eq(f(x), C1 + C2*log(x) + exp(x) - Ei(x)) assert checkodesol(eqn, sol, order=2, solve_for_func=False)[0] assert sol == dsolve(eqn, f(x), prep=False, hint='nth_algebraic')
def test_issue_3583(): assert gruntz(exp(2 * Ei(-x)) / x**2, x, 0) == exp(2 * EulerGamma)
def test_manualintegrate_trivial_substitution(): assert manualintegrate((exp(x) - exp(-x)) / x, x) == -Ei(-x) + Ei(x) f = Function('f') assert manualintegrate((f(x) - f(-x))/x, x) == \ -Integral(f(-x)/x, x) + Integral(f(x)/x, 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_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{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 )}' # 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 _get_examples_ode_sol_nth_algebraic(): M, m, r, t = symbols('M m r t') phi = Function('phi') # This one needs a substitution f' = g. # 'algeb_12': { # 'eq': -exp(x) + (x*Derivative(f(x), (x, 2)) + Derivative(f(x), x))/x, # 'sol': [Eq(f(x), C1 + C2*log(x) + exp(x) - Ei(x))], # }, return { 'hint': "nth_algebraic", 'func': f(x), 'examples': { 'algeb_01': { 'eq': f(x) * f(x).diff(x) * f(x).diff(x, x) * (f(x) - 1) * (f(x).diff(x) - x), 'sol': [Eq(f(x), C1 + x**2 / 2), Eq(f(x), C1 + C2 * x)] }, 'algeb_02': { 'eq': f(x) * f(x).diff(x) * f(x).diff(x, x) * (f(x) - 1), 'sol': [Eq(f(x), C1 + C2 * x)] }, 'algeb_03': { 'eq': f(x) * f(x).diff(x) * f(x).diff(x, x), 'sol': [Eq(f(x), C1 + C2 * x)] }, 'algeb_04': { 'eq': Eq( -M * phi(t).diff(t), Rational(3, 2) * m * r**2 * phi(t).diff(t) * phi(t).diff(t, t)), 'sol': [ Eq(phi(t), C1), Eq(phi(t), C1 + C2 * t - M * t**2 / (3 * m * r**2)) ], 'func': phi(t) }, 'algeb_05': { 'eq': (1 - sin(f(x))) * f(x).diff(x), 'sol': [Eq(f(x), C1)], 'XFAIL': ['separable'] #It raised exception. }, 'algeb_06': { 'eq': (diff(f(x)) - x) * (diff(f(x)) + x), 'sol': [Eq(f(x), C1 - x**2 / 2), Eq(f(x), C1 + x**2 / 2)] }, 'algeb_07': { 'eq': Eq(Derivative(f(x), x), Derivative(g(x), x)), 'sol': [Eq(f(x), C1 + g(x))], }, 'algeb_08': { 'eq': f(x).diff(x) - C1, #this example is from issue 15999 'sol': [Eq(f(x), C1 * x + C2)], }, 'algeb_09': { 'eq': f(x) * f(x).diff(x), 'sol': [Eq(f(x), C1)], }, 'algeb_10': { 'eq': (diff(f(x)) - x) * (diff(f(x)) + x), 'sol': [Eq(f(x), C1 - x**2 / 2), Eq(f(x), C1 + x**2 / 2)], }, 'algeb_11': { 'eq': f(x) + f(x) * f(x).diff(x), 'sol': [Eq(f(x), 0), Eq(f(x), C1 - x)], 'XFAIL': [ 'separable', '1st_exact', '1st_linear', 'Bernoulli', '1st_homogeneous_coeff_best', '1st_homogeneous_coeff_subs_indep_div_dep', '1st_homogeneous_coeff_subs_dep_div_indep', 'lie_group', 'nth_linear_constant_coeff_undetermined_coefficients', 'nth_linear_euler_eq_nonhomogeneous_undetermined_coefficients', 'nth_linear_constant_coeff_variation_of_parameters', 'nth_linear_euler_eq_nonhomogeneous_variation_of_parameters' ] #nth_linear_constant_coeff_undetermined_coefficients raises exception rest all of them misses a solution. }, 'algeb_12': { 'eq': Derivative(x * f(x), x, x, x), 'sol': [Eq(f(x), (C1 + C2 * x + C3 * x**2) / x)], 'XFAIL': ['nth_algebraic' ] # It passes only when prep=False is set in dsolve. }, 'algeb_13': { 'eq': Eq(Derivative(x * Derivative(f(x), x), x) / x, exp(x)), 'sol': [Eq(f(x), C1 + C2 * log(x) + exp(x) - Ei(x))], 'XFAIL': ['nth_algebraic' ] # It passes only when prep=False is set in dsolve. }, } }
def test_checkodesol(): # For the most part, checkodesol is well tested in the tests below. # These tests only handle cases not checked below. raises(ValueError, lambda: checkodesol(f(x, y).diff(x), Eq(f(x, y), x))) raises(ValueError, lambda: checkodesol(f(x).diff(x), Eq(f(x, y), x), f(x, y))) assert checkodesol(f(x).diff(x), Eq(f(x, y), x)) == ( False, -f(x).diff(x) + f(x, y).diff(x) - 1, ) assert checkodesol(f(x).diff(x), Eq(f(x), x)) is not True assert checkodesol(f(x).diff(x), Eq(f(x), x)) == (False, 1) sol1 = Eq(f(x)**5 + 11 * f(x) - 2 * f(x) + x, 0) assert checkodesol(diff(sol1.lhs, x), sol1) == (True, 0) assert checkodesol(diff(sol1.lhs, x) * exp(f(x)), sol1) == (True, 0) assert checkodesol(diff(sol1.lhs, x, 2), sol1) == (True, 0) assert checkodesol(diff(sol1.lhs, x, 2) * exp(f(x)), sol1) == (True, 0) assert checkodesol(diff(sol1.lhs, x, 3), sol1) == (True, 0) assert checkodesol(diff(sol1.lhs, x, 3) * exp(f(x)), sol1) == (True, 0) assert checkodesol(diff(sol1.lhs, x, 3), Eq(f(x), x * log(x))) == ( False, 60 * x**4 * ((log(x) + 1)**2 + log(x)) * (log(x) + 1) * log(x)**2 - 5 * x**4 * log(x)**4 - 9, ) assert checkodesol(diff(exp(f(x)) + x, x) * x, Eq(exp(f(x)) + x, 0)) == (True, 0) assert checkodesol(diff(exp(f(x)) + x, x) * x, Eq(exp(f(x)) + x, 0), solve_for_func=False) == (True, 0) assert checkodesol( f(x).diff(x, 2), [ Eq(f(x), C1 + C2 * x), Eq(f(x), C2 + C1 * x), Eq(f(x), C1 * x + C2 * x**2) ], ) == [(True, 0), (True, 0), (False, C2)] assert checkodesol( f(x).diff(x, 2), set([ Eq(f(x), C1 + C2 * x), Eq(f(x), C2 + C1 * x), Eq(f(x), C1 * x + C2 * x**2), ]), ) == set([(True, 0), (True, 0), (False, C2)]) assert checkodesol(f(x).diff(x) - 1 / f(x) / 2, Eq(f(x)**2, x)) == [ (True, 0), (True, 0), ] assert checkodesol(f(x).diff(x) - f(x), Eq(C1 * exp(x), f(x))) == (True, 0) # Based on test_1st_homogeneous_coeff_ode2_eq3sol. Make sure that # checkodesol tries back substituting f(x) when it can. eq3 = x * exp(f(x) / x) + f(x) - x * f(x).diff(x) sol3 = Eq(f(x), log(log(C1 / x)**(-x))) assert not checkodesol(eq3, sol3)[1].has(f(x)) # This case was failing intermittently depending on hash-seed: eqn = Eq(Derivative(x * Derivative(f(x), x), x) / x, exp(x)) sol = Eq(f(x), C1 + C2 * log(x) + exp(x) - Ei(x)) assert checkodesol(eqn, sol, order=2, solve_for_func=False)[0] eq = x**2 * (f(x).diff(x, 2)) + x * (f(x).diff(x)) + (2 * x**2 + 25) * f(x) sol = Eq( f(x), C1 * besselj(5 * I, sqrt(2) * x) + C2 * bessely(5 * I, sqrt(2) * x)) assert checkodesol(eq, sol) == (True, 0)
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) is oo assert Shi(-oo) is -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 _get_examples_ode_sol_nth_order_reducible(): return { 'hint': "nth_order_reducible", 'func': f(x), 'examples':{ 'reducible_01': { 'eq': Eq(x*Derivative(f(x), x)**2 + Derivative(f(x), x, 2), 0), 'sol': [Eq(f(x),C1 - sqrt(-1/C2)*log(-C2*sqrt(-1/C2) + x) + sqrt(-1/C2)*log(C2*sqrt(-1/C2) + x))], 'slow': True, }, 'reducible_02': { 'eq': -exp(x) + (x*Derivative(f(x), (x, 2)) + Derivative(f(x), x))/x, 'sol': [Eq(f(x), C1 + C2*log(x) + exp(x) - Ei(x))], 'slow': True, }, 'reducible_03': { 'eq': Eq(sqrt(2) * f(x).diff(x,x,x) + f(x).diff(x), 0), 'sol': [Eq(f(x), C1 + C2*sin(2**Rational(3, 4)*x/2) + C3*cos(2**Rational(3, 4)*x/2))], 'slow': True, }, 'reducible_04': { 'eq': f(x).diff(x, 2) + 2*f(x).diff(x), 'sol': [Eq(f(x), C1 + C2*exp(-2*x))], }, 'reducible_05': { 'eq': f(x).diff(x, 3) + f(x).diff(x, 2) - 6*f(x).diff(x), 'sol': [Eq(f(x), C1 + C2*exp(-3*x) + C3*exp(2*x))], 'slow': True, }, 'reducible_06': { 'eq': f(x).diff(x, 4) - f(x).diff(x, 3) - 4*f(x).diff(x, 2) + \ 4*f(x).diff(x), 'sol': [Eq(f(x), C1 + C2*exp(-2*x) + C3*exp(x) + C4*exp(2*x))], 'slow': True, }, 'reducible_07': { 'eq': f(x).diff(x, 4) + 3*f(x).diff(x, 3), 'sol': [Eq(f(x), C1 + C2*x + C3*x**2 + C4*exp(-3*x))], 'slow': True, }, 'reducible_08': { 'eq': f(x).diff(x, 4) - 2*f(x).diff(x, 2), 'sol': [Eq(f(x), C1 + C2*x + C3*exp(-sqrt(2)*x) + C4*exp(sqrt(2)*x))], 'slow': True, }, 'reducible_09': { 'eq': f(x).diff(x, 4) + 4*f(x).diff(x, 2), 'sol': [Eq(f(x), C1 + C2*x + C3*sin(2*x) + C4*cos(2*x))], 'slow': True, }, 'reducible_10': { 'eq': f(x).diff(x, 5) + 2*f(x).diff(x, 3) + f(x).diff(x), 'sol': [Eq(f(x), C1 + C2*(x*sin(x) + cos(x)) + C3*(-x*cos(x) + sin(x)) + C4*sin(x) + C5*cos(x))], 'slow': True, }, 'reducible_11': { 'eq': f(x).diff(x, 2) - f(x).diff(x)**3, 'sol': [Eq(f(x), C1 - sqrt(2)*I*(C2 + x)*sqrt(1/(C2 + x))), Eq(f(x), C1 + sqrt(2)*I*(C2 + x)*sqrt(1/(C2 + x)))], 'slow': True, }, } }
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
def test_ei(): assert Ei(0) is S.NegativeInfinity assert Ei(oo) is S.Infinity assert Ei(-oo) is 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_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"\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)" 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(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(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)'
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'