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The shared data in shapefile
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There are three kinds of data in shapefile format for three largest European countries (France, Germany, and UK): arc, block and natural city. These three data fit into our model step by step in this paper. 
1. Arc file: generated by building up topological relationship. This is because the original OSM data are without topology, much like digitizing lines without generating coverage -- a topology-based vector data format. Through this preprocessing, all line segments will be assigned a direction and become arcs that meet at nodes and have left and right polygons.
2. Block file: based on the pre-processing, we compute the arc-based networks to extract individual blocks. During the process, the border number is calculated as the topological distance and stored as attribute in shapefile. 
3. Natural city file: We then cluster the smaller blocks into individual groups for the bottom up, which we call natural city here. 



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The core source code
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In the source code, we provide the main function which finish the extraction of block based on arc file. The code of generation of arc and natural city are pretty easy and straighforward, and thus not listed here.