
{{alias}}( x, α, β )
    Evaluates the natural logarithm of the probability density function (PDF)
    for a beta prime distribution with first shape parameter `α` and second
    shape parameter `β` at a value `x`.

    If provided `NaN` as any argument, the function returns `NaN`.

    If `α <= 0` or `β <= 0`, the function returns `NaN`.

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

    α: number
        First shape parameter.

    β: number
        Second shape parameter.

    Returns
    -------
    out: number
        Natural logarithm of the PDF.

    Examples
    --------
    > var y = {{alias}}( 0.5, 1.0, 1.0 )
    ~-0.811
    > y = {{alias}}( 0.5, 2.0, 4.0 )
    ~-0.13
    > y = {{alias}}( 0.2, 2.0, 2.0 )
    ~-0.547
    > y = {{alias}}( 0.8, 4.0, 4.0 )
    ~-0.43
    > y = {{alias}}( -0.5, 4.0, 2.0 )
    -Infinity

    > y = {{alias}}( 0.5, -1.0, 0.5 )
    NaN
    > y = {{alias}}( 0.5, 0.5, -1.0 )
    NaN

    > y = {{alias}}( NaN, 1.0, 1.0 )
    NaN
    > y = {{alias}}( 0.5, NaN, 1.0 )
    NaN
    > y = {{alias}}( 0.5, 1.0, NaN )
    NaN


{{alias}}.factory( α, β )
    Returns a function for evaluating the natural logarithm of the probability
    density function (PDF) of a beta prime distribution with first shape
    parameter `α` and second shape parameter `β`.

    Parameters
    ----------
    α: number
        First shape parameter.

    β: number
        Second shape parameter.

    Returns
    -------
    fcn: Function
        Function to evaluate the natural logarithm of the PDF.

    Examples
    --------
    > var mylogpdf = {{alias}}.factory( 0.5, 0.5 );
    > var y = mylogpdf( 0.8 )
    ~-1.62
    > y = mylogpdf( 0.3 )
    ~-0.805

    See Also
    --------

