Edge Bundling Method Based on Homologous Control Points

Abstract

Edge bundling is an effective method to reduce the visual clutter caused by the visualization of the node-link diagram with a large number of complex connections.Generally,the edge bundling based on spatial proximity will lead to independent edge ambiguity and give users a wrong perception.However,focusing only on topological structure of graphs cannot reduce visual clutter caused by dense connections to a large extent.The method based on edge path can control and bundle the edges by using the original nodes in the graph,avoid independent edge ambiguity,and show the advanced mode of data.Therefore,an edge bundling method based on homologous control points is proposed to improve the edge path method.Based on the topology structure information of the graph,the method can calculate homologous control points and select edge control points by using the shortest path algorithm.Then the degree of edge aggregation is optimized with the thinking of gradation.Finally,the edges are smoothed through Bezier curves and colored according to the direction of the edges.The edge bundling method based on homologous control points is used in the US migration dataset and the Chinese railway line dataset.Experimental results show that this method has a good effect on improving the problem of over-bundling.Compared with the original method,this method retains more local data details,balances the bundling degree between the whole and local edges,and can be effectively used for the visualization of complex connected graphs.

Keywords

• node-link diagrams|homologous control points|shortest path|edge bundling|graph visualization