def discrete_likelihood(data, xmin, alpha):
    """
    Equation B.8 in Clauset

    Given a data set, an xmin value, and an alpha "scaling parameter", computes
    the log-likelihood (the value to be maximized)
    """
    if not scipyOK:
        raise ImportError("Can't import scipy.  Need scipy for zeta function.")
    from scipy.special import zeta as zeta

    zz = data[data>=xmin]
    nn = len(zz)

    sum_log_data = np.log(zz).sum()

    zeta = zeta(alpha, xmin)

    L_of_alpha = -1*nn*log(zeta) - alpha * sum_log_data

    return L_of_alpha
Equation B.8 in Clauset

    Given a data set, an xmin value, and an alpha "scaling parameter", computes
    the log-likelihood (the value to be maximized)