def convert_alpha_exponent(alpha):
    """Convert a DFA alpha value to the expected powerlaw exponent.

    Parameters
    ----------
    alpha : float
        Alpha value from a detrended fluctuation analysis.

    Returns
    -------
    exponent : float
        Predicted aperiodic exponent value, representing a 1/f distribution.

    References
    ----------
    .. [1] Schaefer, A., Brach, J. S., Perera, S., & Sejdić, E. (2014). A comparative analysis
           of spectral exponent estimation techniques for 1/fβ processes with applications to the
           analysis of stride interval time series. Journal of Neuroscience Methods, 222, 118–130.
           https://doi.org/10.1016/j.jneumeth.2013.10.017

    Examples
    --------
    Convert a DFA alpha value to the expected powerlaw exponent:

    >>> convert_alpha_exponent(1)
    -1.0
    """

    return -2. * alpha + 1