{{alias}}( t, sigma )
    Evaluates the moment-generating function (MGF) for a Rayleigh distribution
    with scale parameter `sigma` at a value `t`.

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

    If provided a negative value for `sigma`, the function returns `NaN`.

    Parameters
    ----------
    t: number
        Input value.

    sigma: number
        Scale parameter.

    Returns
    -------
    out: number
        Evaluated MGF.

    Examples
    --------
    > var y = {{alias}}( 1.0, 3.0 )
    ~678.508
    > y = {{alias}}( 1.0, 2.0 )
    ~38.65
    > y = {{alias}}( -1.0, 4.0 )
    ~-0.947
    > y = {{alias}}( NaN, 1.0 )
    NaN
    > y = {{alias}}( 0.0, NaN )
    NaN
    > y = {{alias}}( 0.5, -1.0 )
    NaN


{{alias}}.factory( sigma )
    Returns a function for evaluating the moment-generating function (MGF) of a
    Rayleigh distribution with scale parameter `sigma`.

    Parameters
    ----------
    sigma: number
        Scale parameter.

    Returns
    -------
    mgf: Function
        Moment-generating function (MGF).

    Examples
    --------
    > var myMGF = {{alias}}.factory( 0.5 );
    > var y = myMGF( 1.0 )
    ~2.715
    > y = myMGF( 0.5 )
    ~1.888

    See Also
    --------