Editing Quadtree (section)

===Point-region (PR) quadtree===
Point-region (PR) quadtrees<ref>{{Cite journal|last=Orenstein|first=J. A.|year=1982|title=Multidimensional tries used for associative searching|journal=Information Processing Letters|publisher=Elsevier|volume=14 | issue = 4 |pages=150–157|doi=10.1016/0020-0190(82)90027-8}}</ref><ref>{{Cite journal|last=Samet|first=H.|year=1984|title=The quadtree and related hierarchical data structures|url=http://www.cs.umd.edu/~hjs/pubs/SameCSUR84-ocr.pdf|journal=ACM Computing Surveys |publisher=ACM|volume=16 | issue = 2 |pages=187–260|doi=10.1145/356924.356930|s2cid=10319214}}</ref> are very similar to region quadtrees. The difference is the type of information stored about the cells. In a region quadtree, a uniform value is stored that applies to the entire area of the cell of a leaf. The cells of a PR quadtree, however, store a list of points that exist within the cell of a leaf. As mentioned previously, for trees following this decomposition strategy the height depends on the spatial distribution of the points. Like the point quadtree, the PR quadtree may also have a linear height when given a "bad" set.