  In this paper, we propose a novel space partitioning strategy for implicit
hierarchy visualization such that the new plot not only has a tidy layout
similar to the treemap, but also is flexible to data changes similar to the
Voronoi treemap. To achieve this, we define a new distance function and
neighborhood relationship between sites so that space will be divided by
axis-aligned segments. Then a sweepline+skyline based heuristic algorithm is
proposed to allocate the partitioned spaces to form an orthogonal Voronoi
diagram with orthogonal rectangles. To the best of our knowledge, it is the
first time to use a sweepline-based strategy for the Voronoi treemap. Moreover,
we design a novel strategy to initialize the diagram status and modify the
status update procedure so that the generation of our plot is more effective
and efficient. We show that the proposed algorithm has an O(nlog(n)) complexity
which is the same as the state-of-the-art Voronoi treemap. To this end, we show
via experiments on the artificial dataset and real-world dataset the
performance of our algorithm in terms of computation time, converge rate, and
aspect ratio. Finally, we discuss the pros and cons of our method and make a
conclusion.
