The search radii corresponding to P1 is δ1, and has a permanent tendency to reduce, while the search radii corresponding to P2 is δ2, and it has a permanent tendency to increase. Thus, the points generated by P1 will be increasingly focused around P1 with iterations while those generated by P2 will be increasingly dissipated around P2. This corresponds to a gradual increase in the exploitative aspect of the points generated from point P1 as well as the gradual increase in the explorative aspect of the points generated from point P2.