
{{alias}}( σ )
    Returns the standard deviation of a Rayleigh distribution.

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

    If provided `σ < 0`, the function returns `NaN`.

    Parameters
    ----------
    σ: number
        Scale parameter.

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

    Examples
    --------
    > var v = {{alias}}( 9.0 )
    ~5.896
    > v = {{alias}}( 4.5 )
    ~2.948

    See Also
    --------

