
{{alias}}( x, k, λ )
    Evaluates the natural logarithm of the probability density function (PDF)
    for an Erlang distribution with shape parameter `k` and rate parameter `λ`
    at a value `x`.

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

    If not provided a nonnegative integer for `k`, the function returns `NaN`.

    If provided a non-positive value for `λ`, the function returns `NaN`.

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

    k: number
        Shape parameter.

    λ: number
        Rate parameter.

    Returns
    -------
    out: number
        Evaluated logPDF.

    Examples
    --------
    > var y = {{alias}}( 0.1, 1, 1.0 )
    ~-0.1
    > y = {{alias}}( 0.5, 2, 2.5 )
    ~-0.111
    > y = {{alias}}( -1.0, 4, 2.0 )
    -Infinity
    > y = {{alias}}( NaN, 1, 1.0 )
    NaN
    > y = {{alias}}( 0.0, NaN, 1.0 )
    NaN
    > y = {{alias}}( 0.0, 1, NaN )
    NaN
    > y = {{alias}}( 2.0, -2, 0.5 )
    NaN
    > y = {{alias}}( 2.0, 0.5, 0.5 )
    NaN
    > y = {{alias}}( 2.0, 0.0, 2.0 )
    -Infinity
    > y = {{alias}}( 0.0, 0.0, 2.0 )
    Infinity
    > y = {{alias}}( 2.0, 1, 0.0 )
    NaN
    > y = {{alias}}( 2.0, 1, -1.0 )
    NaN


{{alias}}.factory( k, λ )
    Returns a function for evaluating the natural logarithm of the probability
    density function (PDF) of an Erlang distribution with shape parameter `k`
    and rate parameter `λ`.

    Parameters
    ----------
    k: number
        Shape parameter.

    λ: number
        Rate parameter.

    Returns
    -------
    logpdf: Function
        Logarithm of probability density function (PDF).

    Examples
    --------
    > var myLogPDF = {{alias}}.factory( 6.0, 7.0 );
    > y = myLogPDF( 7.0 )
    ~-32.382


    See Also
    --------

