line graph

[mdeff]

graph = pg.graphs.Sensor(5, k=2, seed=10)
line_graph = pg.graphs.LineGraph(graph)
fig, ax = plt.subplots()
graph.plot(vertex_color='blue', edge_color='blue', indices=True, ax=ax)
line_graph.plot(vertex_color='red', edge_color='red', indices=True, ax=ax)
ax.set_title('graph and its line graph')

Todo:

• Check for directed graphs.
• Any way to set the edge weight?

Should be consistent with NetworkX's line_graph.

[coveralls]

Coverage increased (+0.07%) to 88.13% when pulling cf8f988 on line-graph into 8ce5bde on master.

[nperraud]

For the edge weight, I think we should think about the properties we want the graph to have. So let us do some math. For now we could raise a warning if the original graph is weighted.

[mdeff]

Agreed. Warning added. For now, it creates a binary line graph in all cases (as if the original graph was unweighted).

[nperraud]

This looks fine for me...