Adjacency-Preserving Spatial Treemaps

TL;DR

This paper introduces algorithms for converting arbitrary rectangular layouts into hierarchical spatial treemaps that preserve clustering and adjacency relationships, enhancing visualization of spatial data.

Contribution

It presents novel algorithms for transforming non-hierarchical layouts into adjacency-preserving spatial treemaps with hierarchical clustering.

Findings

Algorithms effectively preserve adjacency in treemaps.

Transformations maintain hierarchical clustering.

Applicable to geographic and political spatial visualizations.

Abstract

Rectangular layouts, subdivisions of an outer rectangle into smaller rectangles, have many applications in visualizing spatial information, for instance in rectangular cartograms in which the rectangles represent geographic or political regions. A spatial treemap is a rectangular layout with a hierarchical structure: the outer rectangle is subdivided into rectangles that are in turn subdivided into smaller rectangles. We describe algorithms for transforming a rectangular layout that does not have this hierarchical structure, together with a clustering of the rectangles of the layout, into a spatial treemap that respects the clustering and also respects to the extent possible the adjacencies of the input layout.