(z)
return expint(1, z)
Classical case of the generalized exponential integral.

    This is equivalent to ``expint(1, z)``.

    See Also
    ========

    Ei: Exponential integral.
    expint: Generalised exponential integral.
    li: Logarithmic integral.
    Li: Offset logarithmic integral.
    Si: Sine integral.
    Ci: Cosine integral.
    Shi: Hyperbolic sine integral.
    Chi: Hyperbolic cosine integral.
Classical case of the generalized exponential integral.
Classical case of the generalized exponential integral .
def E1(z):
    """
    Classical case of the generalized exponential integral.

    This is equivalent to ``expint(1, z)``.

    See Also
    ========

    Ei: Exponential integral.
    expint: Generalised exponential integral.
    li: Logarithmic integral.
    Li: Offset logarithmic integral.
    Si: Sine integral.
    Ci: Cosine integral.
    Shi: Hyperbolic sine integral.
    Chi: Hyperbolic cosine integral.
    """
    return expint(1, z)
def E1 ( z ) : return expint ( 1 , z )