Drawing Graphs:Conclusion

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Conclusion

In this Chapter we have described just a small sample of graph drawing algorithms. Notable omissions include:

• Force directed methods: A graph can be used to define a system of forces. For example, we can define a Hooke’s law spring force between two adjacent vertices, and magnetic repulsion between nonadjacent vertices. A minimum energy

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FIGURE 46.17: Local transformations to transform a visibility representation to an orthogonal drawing.

configuration of the graph can lead to a good drawing. For methods using the force-directed paradigm.

• Clustered graph drawing methods: in practice, to handle large graphs, one needs to form clusters of the vertices to form “super-vertices”. Drawing graphs in which some vertices represent graphs is a challenging problem.

• Three dimensional graph drawing methods: the widespread availability of cheap three dimensional graphics systems has lead to the investigation of graph drawing in three dimensions.

• Crossing minimization methods: in this Chapter we have concentrated on planar graphs. In practice, we need to deal with non-planar graphs, by choosing a drawing with a small number of crossings.

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