The algorithm of constructing a recursive partition tree is illustrated as follows.
The graphic description in Fig. 9 gives an simplified but intuitive explanation of the hierarchical structure. The structure is a tree. The root corresponds to the entire space of all the possible inputs. The children of the root partition the space into large cells, as shown by thick lines in Fig. 9. The children of a parent subdivide the parent's cell future into smaller cells, and so on.
Figure 9:
A 2-D illustration of a recursive partition tree. The samples surrounded
by circles
or rectangulars are the centers of the subregions.
Left: the partition. Right:
the corresponding recursive partition tree.