NORMA 3.0: aesthetic and group-aware visualization and analysis of annotated biological networks

Abstract

Summary: Interpreting a biological network often rests on the relationship between its connectivity and the functional groups annotated on it, such as pathways, complexes, or enriched terms. For example, whether a group forms a cohesive module, how groups overlap, and which proteins connect them. These relationships are often hard to assess visually when groups are numerous or overlap, and most tools represent membership only by node color. NORMA 3.0 is a complete client-side rewrite of its predecessors, delineating and laying out groups with convex hulls, bubble sets, or fog clouds. Multi-group nodes are rendered as pies and directed, and parallel edges retain their evidence channels. Eighteen 2D and nine 3D layouts are scored by silhouette width, outline intrusion and overlap, and benchmarked for group separation and run time. The implementation also includes edge bundling, network importers for six databases, 21 topological measures, group-level and enrichment statistics, comparison of up to ten networks, export of high-resolution images, and an Application Programming Interface. Availability and implementation: NORMA 3.0 is freely available at https://normaviz.org. The source code is available at https://github.com/PavlopoulosLab/NORMA.