Fig. : The best fit (blue) onto the curve (red) given by . A q-BWF is used (the values of α, ξ and q-parameters are given in the figure). The misfit is proposed in the lower part of the plot. The fitting calculation is obtained by minimizing the sum of the squares of the deviations (sum from n=1 to n=230). The value of this sum is 8.5 x 10 -4 .