
{{alias}}( x )
    Evaluates the natural logarithm of the factorial of `x`.

    For input values other than negative integers, the function returns

      ln( x! ) = ln( Γ(x+1) )

    where `Γ` is the Gamma function. For negative integers, the function returns
    `NaN`.

    If provided `NaN`, the function returns `NaN`.

    Parameters
    ----------
    x: number
        Input value.

    Returns
    -------
    y: number
        Natural logarithm of the factorial of `x`.

    Examples
    --------
    > var y = {{alias}}( 3.0 )
    ~1.792
    > y = {{alias}}( 2.4 )
    ~1.092
    > y = {{alias}}( -1.0 )
    NaN
    > y = {{alias}}( -1.5 )
    ~1.266
    > y = {{alias}}( NaN )
    NaN

    See Also
    --------

