
{{alias}}( k, λ )
    Returns the standard deviation of an Erlang distribution.

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

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

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

    Parameters
    ----------
    k: integer
        Shape parameter.

    λ: number
        Rate parameter.

    Returns
    -------
    out: number
        Standard deviation.

    Examples
    --------
    > var v = {{alias}}( 1, 1.0 )
    1.0
    > v = {{alias}}( 4, 12.0 )
    ~0.167
    > v = {{alias}}( 8, 2.0 )
    ~1.414

    See Also
    --------

