'TODO: check scaling of r-learing: seems worse than linear: 9e3 25e3 65e3 (10,20,40-D)'

def __init__(self, x0, sigma0, randn=np.random.randn):

    self.N = len(x0)
    N = self.N
    self.dampi = (4 * N)
    self.eta_r = ((0 / N) / 3)
    self.mu = 1
    self.use_abs_sigma = 1
    self.use_abs_sigma_r = 1
    self.randn = randn
    self.x0 = array(x0, copy=True)
    self.sigma0 = sigma0
    self.cs = (1 / (N ** 0.5))
    self.damps = 1
    self.use_sign = 0
    self.use_scalar_product = 0
    self.csr = (1 / (N ** 0.5))
    self.dampsr = ((4 * N) ** 0.5)
    self.chi1 = ((2 / np.pi) ** 0.5)
    self.chiN = ((N ** 0.5) * ((1 - (1.0 / (4.0 * N))) + (1.0 / (21.0 * (N ** 2)))))
    self.initialize()
