{{alias}}( α, β )
    Returns the standard deviation of an inverse gamma distribution.

    If `α <= 2` or `β <= 0`, the function returns `NaN`.

    If `α` or `β` is `NaN`, the function returns `NaN`.

    Parameters
    ----------
    α: number
        Shape parameter.

    β: number
        Rate parameter.

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

    Examples
    --------
    > var v = {{alias}}( 5.0, 7.0 )
    ~1.01
    > v = {{alias}}( 4.0, 12.0 )
    ~2.828
    > v = {{alias}}( 8.0, 2.0 )
    ~0.117

    See Also
    --------