def plato_to_sg(deg_plato):
    """
    Degrees Plato to Specific Gravity

    :param float deg_plato: Degrees Plato
    :return: Specific Gravity
    :rtype: float

    The simple formula for S.G. is:

    :math:`\\text{SG} = 1 + 0.004 \\times \\text{Plato}`

    The more precise calculation of SG is:

    :math:`\\text{SG} = \\frac{Plato}{258.6 - \\big(\\frac{Plato}{258.2} \\times 227.1\\big)} + 1`

    Source:

    * http://www.learntobrew.com/page/1mdhe/Shopping/Beer_Calculations.html
    """  # noqa
    return (deg_plato / (258.6 - ((deg_plato / 258.2) * 227.1))) + 1.0