Figure 4

The diagrams of the moving step. f(Xpeak) is the peak value of the function in the group, the corresponding value in x axis is xpeak. f(Xmax) is the max value in the group, the corresponding value in x axis is xmax. f(Xm) is a mass value of a surrounding dust in the group, the corresponding value in x axis is x_m. f(Xv) is the valley which is nearer than other valleys in the group, the corresponding value in x axis is x_v. The sub-figure (a) is shown as the kind of the peak value must be found in the group. The sub-figure (b) and (c) are shown as the kind of the x_max will be the pseudo peak value with probability p.