cityImage.clean_network#

cityImage.clean_network(nodes_gdf, edges_gdf, dead_ends=False, remove_islands=True, same_vertexes_edges=True, self_loops=False, fix_topology=False, preserve_direction=False, nodes_to_keep_regardless=None)[source]#

Cleans a street network by applying a series of topology and geometry corrections to nodes and edges GeoDataFrames.

This function can:

  • Remove pseudo-nodes

  • Remove duplicate nodes and edges (by geometry or node pairing)

  • Remove disconnected islands (optional)

  • Remove edges with the same vertexes but different geometry (optional)

  • Remove dead-ends (optional)

  • Remove self-loops (optional)

  • Fix topology by breaking lines at intersections (optional)

Parameters:

  • nodes_gdf (GeoDataFrame) – Point GeoDataFrame containing network nodes (junctions), must include a unique node ID column.

  • edges_gdf (GeoDataFrame) – LineString GeoDataFrame containing street segments, must include columns for start/end node IDs and geometry.

  • dead_ends (bool, optional) – If True, removes dead-end nodes and corresponding edges. Default is False.

  • remove_islands (bool, optional) – If True, removes disconnected components (“islands”) in the network. Default is True.

  • same_vertexes_edges (bool, optional) – If True, treats multiple edges between the same pair of nodes as duplicates. Keeps only the longest edge when it is at least 10% longer than the others, otherwise replaces them with a center line. Default is True.

  • self_loops (bool, optional) – If True, removes self-loop edges (where start and end node are the same). Default is False.

  • fix_topology (bool, optional) – If True, breaks lines at intersections with other lines in the streets GeoDataFrame. Default is False.

  • preserve_direction (bool, optional) – If True, considers edge direction: edges with the same coordinates but opposite directions are not considered duplicates. If False, such edges are treated as duplicates. Default is False.

  • nodes_to_keep_regardless (list, optional) – List of node IDs to always keep, even if they would otherwise be removed (e.g. for transport stations). Default is empty list.

Returns:

  • nodes_gdf (GeoDataFrame) – Cleaned nodes GeoDataFrame.

  • edges_gdf (GeoDataFrame) – Cleaned edges GeoDataFrame.