Multiscale Visualization and Exploration of Large Bipartite Graphs

Abstract: A bipartite graph is a powerful abstraction for modeling relationships between two collections. Visualizations of bipartite graphs allow users to understand the mutual relationships between the elements in the two collections, e.g., by identifying clusters of similarly connected elements. However, commonly-used visual representations do not scale for the analysis of large bipartite graphs containing tens of millions of vertices, often resorting to an a-priori clustering of the sets. To address this issue, we present the Who's-Active-On-What-Visualization (WAOW-Vis) that allows for multiscale exploration of a bipartite social network without imposing an a-priori clustering. To this end, we propose to treat a bipartite graph as a high-dimensional space and we create the WAOW-Vis adapting the multiscale dimensionality-reduction technique HSNE. The application of HSNE for bipartite graph requires several modifications that form the contributions of this work. Given the nature of the problem, a set-based similarity is proposed. For efficient and scalable computations, we use compressed bitmaps to represent sets and we present a novel space partitioning tree to efficiently compute similarities; the Sets Intersection Tree. Finally, we validate WAOWVis on several datasets connecting Twitter-users and -streams in different domains: news, computer science and politics. We show how WAOW-Vis is particularly effective in identifying hierarchies of communities among social-media users.

Nicola Pezzotti, Jean-Daniel Fekete, Thomas Höllt, Boudewijn Lelieveldt, Elmar Eisemann, and Anna Vilanova. Multiscale Visualization and Exploration of Large Bipartite Graphs. Computer Graphics Forum (Proceedings of EuroVis 2018), 37(3): pp. 549–560, 2018.
@article { bib:2018_eurovis_waowvis,
author = { Nicola Pezzotti and Jean-Daniel Fekete and Thomas H{\"o}llt and Boudewijn Lelieveldt and Elmar Eisemann and Anna Vilanova },
title = { Multiscale Visualization and Exploration of Large Bipartite Graphs },
journal = { Computer Graphics Forum (Proceedings of EuroVis 2018) },
volume = { 37 },
number = { 3 },
pages = { 549 -- 560 },
year = { 2018 },
doi = { 10.1111/cgf.13441 },
}