def test__eis(): assert _eis(z).diff(z) == -_eis(z) + 1 / z assert _eis(1/z).series(z) == \ z + z**2 + 2*z**3 + 6*z**4 + 24*z**5 + O(z**6) assert Ei(z).rewrite('tractable') == exp(z) * _eis(z) assert li(z).rewrite('tractable') == z * _eis(log(z)) assert _eis(z).rewrite('intractable') == exp(-z) * Ei(z) assert expand(li(z).rewrite('tractable').diff(z).rewrite('intractable')) \ == li(z).diff(z) assert expand(Ei(z).rewrite('tractable').diff(z).rewrite('intractable')) \ == Ei(z).diff(z) assert _eis(z).series(z, n=3) == EulerGamma + log(z) + z*(-log(z) - \ EulerGamma + 1) + z**2*(log(z)/2 - S(3)/4 + EulerGamma/2) + O(z**3*log(z)) raises(ArgumentIndexError, lambda: _eis(z).fdiff(2))
def test__eis(): assert _eis(z).diff(z) == -_eis(z) + 1/z assert _eis(1/z).series(z) == \ z + z**2 + 2*z**3 + 6*z**4 + 24*z**5 + O(z**6) assert Ei(z).rewrite('tractable') == exp(z)*_eis(z) assert li(z).rewrite('tractable') == z*_eis(log(z)) assert _eis(z).rewrite('intractable') == exp(-z)*Ei(z) assert expand(li(z).rewrite('tractable').diff(z).rewrite('intractable')) \ == li(z).diff(z) assert expand(Ei(z).rewrite('tractable').diff(z).rewrite('intractable')) \ == Ei(z).diff(z) assert _eis(z).series(z, n=3) == EulerGamma + log(z) + z*(-log(z) - \ EulerGamma + 1) + z**2*(log(z)/2 - S(3)/4 + EulerGamma/2) + O(z**3*log(z))
def test__eis(): assert _eis(z).diff(z) == -_eis(z) + 1 / z assert _eis(1/z).series(z) == \ z + z**2 + 2*z**3 + 6*z**4 + 24*z**5 + O(z**6) assert Ei(z).rewrite('tractable') == exp(z) * _eis(z) assert li(z).rewrite('tractable') == z * _eis(log(z)) assert _eis(z).rewrite('intractable') == exp(-z) * Ei(z) assert expand(li(z).rewrite('tractable').diff(z).rewrite('intractable')) \ == li(z).diff(z) assert expand(Ei(z).rewrite('tractable').diff(z).rewrite('intractable')) \ == Ei(z).diff(z)
def test__eis(): assert _eis(z).diff(z) == -_eis(z) + 1/z assert _eis(1/z).series(z) == \ z + z**2 + 2*z**3 + 6*z**4 + 24*z**5 + O(z**6) assert Ei(z).rewrite('tractable') == exp(z)*_eis(z) assert li(z).rewrite('tractable') == z*_eis(log(z)) assert _eis(z).rewrite('intractable') == exp(-z)*Ei(z) assert expand(li(z).rewrite('tractable').diff(z).rewrite('intractable')) \ == li(z).diff(z) assert expand(Ei(z).rewrite('tractable').diff(z).rewrite('intractable')) \ == Ei(z).diff(z)