I'm interested in computing a line graph for an input graph, preferably in GRASS since I'll be using other GRASS network analysis tools afterwards. I couldn't find any reference to line graphs in the GRASS docs. Is there a different term I should be using in my search or a hidden function that would create such a graph?
For context:
the line graph of an undirected graph G is another graph L(G) that represents the adjacencies between edges of G.
If Python is okay, then there are some good Python modules that know about line graphs. One example is NetworkX (which I installed with simply sudo pip install networkx).
This is not a perfect answer since you need to write some glue code. First you would convert your input into NetworkX graph objects:
import networkx as nx
G = nx.Graph()
G.add_node( ... )
G.add_edge( ... )
Then you'd call the line_graph function get NetworkX to compute the line graph:
H = nx.line_graph(G)
And finally you would convert the result back to something useful by iterating over H.edges() and H.nodes().
