Visualizing and Animating Search Operations on Quadtrees on the Worldwide Web.
František Brabec, Hanan Samet · 2000
A set of spatial index JAVATM applets is described that enable users on the worldwide web to experiment with a number of variants of the quadtree spatial data structure for different spatial data types, and, most importantly, enable them to see in an animated manner how a number of basic search operations are executed for them. The spatial data types are points, line segments, and rectangles. The search operations are finding nearest neighbors from an object of arbitrary type and shape, and retrieving all objects that overlap an object of arbitrary type and shape or are within a given distance of an object of arbitrary type and shape. The nearest neighbor and within queries retrieve their results in the order of their distance from the given query object. The representations and algorithms are visualized and animated in a consistent manner using the same primitives so that the differences between the effects of the representations can be easily understood. The applets can be found at http://www.cs.umd.edu/~hjs/quadtree/index.html.