an alternative reincarnation of the original treemap concept, which itself is a widely used compact visualization of directory tree structure in a space-filling way. here, rectangles are replaced by circles. it has the advantage that zooming in on directories is efficient because the layout does not need to be recalculated, & that the aspect ratio of nodes stays constant, although the circular areas do not tend to fill the available space as effectively. see also voronoi treemap & color project.
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