Robustness Analysis of City Road Network at Different Granularities - Space-Time Integration in Geography and GIScience - page 130

Fig. 8.4 Beijing road segments

Fig. 8.5 Three dual graphs of Beijing road network

In Fig. 8.5 , the position of each segment/stroke/community is not based on its
location in the real world. In this figure, we use GEM (Generalization Expectation-
Maximization) (Dempster et al. 1977 ) algorithm provided by GUESS to layout
the nodes and edges. The layout principle of this algorithm is to minimize the
overlapping of edges. The significant variations of the three graphs imply that dual
graph can provide more insight on the urban road structure. To compare three dual
graphs quantitatively, we characterize the network structure with several metrics of
complex network theory.