A physics-based approach for interactive manipulation of graph visualizations

Abstract

This paper presents an interactive physics-based technique for the exploration and dynamic reorganization of graph layouts that takes into account semantic properties which the user might need to emphasize. Many techniques have been proposed that take a graph as input and produce a visualization solely based on its topology, seldom ever relying on the semantic attributes of nodes and edges. These automatic topology-based algorithms might generate aesthetically interesting layouts, but they neglect information that might be important for the user. Among these are the force-directed or energy minimization algorithms, which use physics analogies to produce satisfactory layouts. They consist of applying forces on the nodes, which move until the physical system enters a state of mechanical equilibrium. We propose an extension of this metaphor to include tools for the interactive manipulation of such layouts. These tools are comprised of magnets, which attract nodes with user-specified criteria to the regions surrounding the magnets. Magnets can be nested and also used to intuitively perform set operations such as union and intersection, becoming thus an intuitive visual tool for sorting through the datasets. To evaluate the technique we discuss how they can be used to perform common graph visualization tasks.

FlexiView: A Magnet-Based Approach for Visualizing Requirements Artifacts

“…A particular thread of work deals with manipulating graph visualizations based on a physical metaphor [9], treating graph nodes as metal balls and edges as springs that are flexibly attached to those balls [2]. By applying forces to such a network of balls and springs, for example by placing magnets, interesting parts of a graph can be highlighted or magnified [11], thus allowing the construction of intuitive, user-friendly graph visualization and navigation mechanisms.…”

“…To manipulate the size of the regions, we model the region boundaries with a physical spring model [2] (Fig. 1a) and apply forces to that model using virtual magnets [11] (Fig. 1b).…”

“…As in other work [11], we do not strive for physical accuracy, modeling exactly Hooke's law for the springs and the laws of magnetism for the magnets, but use the physical model as a metaphor for guiding algorithm design. The users of FlexiView will not have to bother with physics.…”

“…Based on a physical metaphor of magnets and springs [2], [9], [11], FlexiView shall be able to flexibly visualize detailed requirements artifacts without losing the surrounding context within a display canvas of fixed size. In contrast to existing visualization mechanisms, FlexiView will be designed such that it can be used for visualizing both single artifacts (e.g., a graphic model diagram or a sketch) and a network of multiple different artifacts.…”

Towards automated analysis and visualization of distributed software systems

“…Both approaches follow a model-driven concept, while we head towards an information visualization technique. Spritzer and Freitas have developed a magnet metaphor for interactive graph visualization [5], which we have adapted to our scope. Jerding and Stasko have presented the Information Mural [2], which we use to handle massive message trace data.…”