Cells numbers may be used to create an attraction point  in cell space. These numbers can be generated using a function   that monotonically decreases, giving highest values for cells located near that point. With  as a fixed point, for each spot , a list of cells   with , , where . Here
the cell  will be selected for engaging the spot

This arrangement creates some anisotropy around the attraction point , such that spots will select with preference cells located in the vicinity of that point.

Figure 1 shows a convex surface created by cell numbers, with a maximum located at point  . New cells will be born at locations pointed by arrows, as they are closer to , causing cell patterns to move in that direction.